1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.35.4" 127 #define SQLITE_VERSION_NUMBER 3035004 128 #define SQLITE_SOURCE_ID "2021-04-02 15:20:15 5d4c65779dab868b285519b19e4cf9d451d50c6048f06f653aa701ec212df45e" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #else 193 # define sqlite3_compileoption_used(X) 0 194 # define sqlite3_compileoption_get(X) ((void*)0) 195 #endif 196 197 /* 198 ** CAPI3REF: Test To See If The Library Is Threadsafe 199 ** 200 ** ^The sqlite3_threadsafe() function returns zero if and only if 201 ** SQLite was compiled with mutexing code omitted due to the 202 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 203 ** 204 ** SQLite can be compiled with or without mutexes. When 205 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206 ** are enabled and SQLite is threadsafe. When the 207 ** [SQLITE_THREADSAFE] macro is 0, 208 ** the mutexes are omitted. Without the mutexes, it is not safe 209 ** to use SQLite concurrently from more than one thread. 210 ** 211 ** Enabling mutexes incurs a measurable performance penalty. 212 ** So if speed is of utmost importance, it makes sense to disable 213 ** the mutexes. But for maximum safety, mutexes should be enabled. 214 ** ^The default behavior is for mutexes to be enabled. 215 ** 216 ** This interface can be used by an application to make sure that the 217 ** version of SQLite that it is linking against was compiled with 218 ** the desired setting of the [SQLITE_THREADSAFE] macro. 219 ** 220 ** This interface only reports on the compile-time mutex setting 221 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223 ** can be fully or partially disabled using a call to [sqlite3_config()] 224 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226 ** sqlite3_threadsafe() function shows only the compile-time setting of 227 ** thread safety, not any run-time changes to that setting made by 228 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229 ** is unchanged by calls to sqlite3_config().)^ 230 ** 231 ** See the [threading mode] documentation for additional information. 232 */ 233 SQLITE_API int sqlite3_threadsafe(void); 234 235 /* 236 ** CAPI3REF: Database Connection Handle 237 ** KEYWORDS: {database connection} {database connections} 238 ** 239 ** Each open SQLite database is represented by a pointer to an instance of 240 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243 ** and [sqlite3_close_v2()] are its destructors. There are many other 244 ** interfaces (such as 245 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 247 ** sqlite3 object. 248 */ 249 typedef struct sqlite3 sqlite3; 250 251 /* 252 ** CAPI3REF: 64-Bit Integer Types 253 ** KEYWORDS: sqlite_int64 sqlite_uint64 254 ** 255 ** Because there is no cross-platform way to specify 64-bit integer types 256 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 257 ** 258 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260 ** compatibility only. 261 ** 262 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 265 ** between 0 and +18446744073709551615 inclusive. 266 */ 267 #ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269 # ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271 # else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273 # endif 274 #elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277 #else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280 #endif 281 typedef sqlite_int64 sqlite3_int64; 282 typedef sqlite_uint64 sqlite3_uint64; 283 284 /* 285 ** If compiling for a processor that lacks floating point support, 286 ** substitute integer for floating-point. 287 */ 288 #ifdef SQLITE_OMIT_FLOATING_POINT 289 # define double sqlite3_int64 290 #endif 291 292 /* 293 ** CAPI3REF: Closing A Database Connection 294 ** DESTRUCTOR: sqlite3 295 ** 296 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297 ** for the [sqlite3] object. 298 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299 ** the [sqlite3] object is successfully destroyed and all associated 300 ** resources are deallocated. 301 ** 302 ** Ideally, applications should [sqlite3_finalize | finalize] all 303 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 304 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 305 ** with the [sqlite3] object prior to attempting to close the object. 306 ** ^If the database connection is associated with unfinalized prepared 307 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 308 ** sqlite3_close() will leave the database connection open and return 309 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 310 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 311 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 312 ** connection immediately, it marks the database connection as an unusable 313 ** "zombie" and makes arrangements to automatically deallocate the database 314 ** connection after all prepared statements are finalized, all BLOB handles 315 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 316 ** is intended for use with host languages that are garbage collected, and 317 ** where the order in which destructors are called is arbitrary. 318 ** 319 ** ^If an [sqlite3] object is destroyed while a transaction is open, 320 ** the transaction is automatically rolled back. 321 ** 322 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 323 ** must be either a NULL 324 ** pointer or an [sqlite3] object pointer obtained 325 ** from [sqlite3_open()], [sqlite3_open16()], or 326 ** [sqlite3_open_v2()], and not previously closed. 327 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 328 ** argument is a harmless no-op. 329 */ 330 SQLITE_API int sqlite3_close(sqlite3*); 331 SQLITE_API int sqlite3_close_v2(sqlite3*); 332 333 /* 334 ** The type for a callback function. 335 ** This is legacy and deprecated. It is included for historical 336 ** compatibility and is not documented. 337 */ 338 typedef int (*sqlite3_callback)(void*,int,char**, char**); 339 340 /* 341 ** CAPI3REF: One-Step Query Execution Interface 342 ** METHOD: sqlite3 343 ** 344 ** The sqlite3_exec() interface is a convenience wrapper around 345 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 346 ** that allows an application to run multiple statements of SQL 347 ** without having to use a lot of C code. 348 ** 349 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 350 ** semicolon-separate SQL statements passed into its 2nd argument, 351 ** in the context of the [database connection] passed in as its 1st 352 ** argument. ^If the callback function of the 3rd argument to 353 ** sqlite3_exec() is not NULL, then it is invoked for each result row 354 ** coming out of the evaluated SQL statements. ^The 4th argument to 355 ** sqlite3_exec() is relayed through to the 1st argument of each 356 ** callback invocation. ^If the callback pointer to sqlite3_exec() 357 ** is NULL, then no callback is ever invoked and result rows are 358 ** ignored. 359 ** 360 ** ^If an error occurs while evaluating the SQL statements passed into 361 ** sqlite3_exec(), then execution of the current statement stops and 362 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 363 ** is not NULL then any error message is written into memory obtained 364 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 365 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 366 ** on error message strings returned through the 5th parameter of 367 ** sqlite3_exec() after the error message string is no longer needed. 368 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 369 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 370 ** NULL before returning. 371 ** 372 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 373 ** routine returns SQLITE_ABORT without invoking the callback again and 374 ** without running any subsequent SQL statements. 375 ** 376 ** ^The 2nd argument to the sqlite3_exec() callback function is the 377 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 378 ** callback is an array of pointers to strings obtained as if from 379 ** [sqlite3_column_text()], one for each column. ^If an element of a 380 ** result row is NULL then the corresponding string pointer for the 381 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 382 ** sqlite3_exec() callback is an array of pointers to strings where each 383 ** entry represents the name of corresponding result column as obtained 384 ** from [sqlite3_column_name()]. 385 ** 386 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 387 ** to an empty string, or a pointer that contains only whitespace and/or 388 ** SQL comments, then no SQL statements are evaluated and the database 389 ** is not changed. 390 ** 391 ** Restrictions: 392 ** 393 ** <ul> 394 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 395 ** is a valid and open [database connection]. 396 ** <li> The application must not close the [database connection] specified by 397 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 398 ** <li> The application must not modify the SQL statement text passed into 399 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 400 ** </ul> 401 */ 402 SQLITE_API int sqlite3_exec( 403 sqlite3*, /* An open database */ 404 const char *sql, /* SQL to be evaluated */ 405 int (*callback)(void*,int,char**,char**), /* Callback function */ 406 void *, /* 1st argument to callback */ 407 char **errmsg /* Error msg written here */ 408 ); 409 410 /* 411 ** CAPI3REF: Result Codes 412 ** KEYWORDS: {result code definitions} 413 ** 414 ** Many SQLite functions return an integer result code from the set shown 415 ** here in order to indicate success or failure. 416 ** 417 ** New error codes may be added in future versions of SQLite. 418 ** 419 ** See also: [extended result code definitions] 420 */ 421 #define SQLITE_OK 0 /* Successful result */ 422 /* beginning-of-error-codes */ 423 #define SQLITE_ERROR 1 /* Generic error */ 424 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 425 #define SQLITE_PERM 3 /* Access permission denied */ 426 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 427 #define SQLITE_BUSY 5 /* The database file is locked */ 428 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 429 #define SQLITE_NOMEM 7 /* A malloc() failed */ 430 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 431 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 432 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 433 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 434 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 435 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 436 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 437 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 438 #define SQLITE_EMPTY 16 /* Internal use only */ 439 #define SQLITE_SCHEMA 17 /* The database schema changed */ 440 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 441 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 442 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 443 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 444 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 445 #define SQLITE_AUTH 23 /* Authorization denied */ 446 #define SQLITE_FORMAT 24 /* Not used */ 447 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 448 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 449 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 450 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 451 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 452 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 453 /* end-of-error-codes */ 454 455 /* 456 ** CAPI3REF: Extended Result Codes 457 ** KEYWORDS: {extended result code definitions} 458 ** 459 ** In its default configuration, SQLite API routines return one of 30 integer 460 ** [result codes]. However, experience has shown that many of 461 ** these result codes are too coarse-grained. They do not provide as 462 ** much information about problems as programmers might like. In an effort to 463 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 464 ** and later) include 465 ** support for additional result codes that provide more detailed information 466 ** about errors. These [extended result codes] are enabled or disabled 467 ** on a per database connection basis using the 468 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 469 ** the most recent error can be obtained using 470 ** [sqlite3_extended_errcode()]. 471 */ 472 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 473 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 474 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 475 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 507 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 508 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 509 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 510 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 511 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 512 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 513 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 514 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 515 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 516 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 517 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 518 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 519 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 521 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 522 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 529 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 530 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 531 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 532 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 533 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 534 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 535 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 536 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 537 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 538 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 539 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 540 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 541 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 542 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 543 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 544 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 545 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 546 547 /* 548 ** CAPI3REF: Flags For File Open Operations 549 ** 550 ** These bit values are intended for use in the 551 ** 3rd parameter to the [sqlite3_open_v2()] interface and 552 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 553 */ 554 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 555 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 557 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 558 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 559 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 560 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 561 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 562 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 563 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 564 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 565 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 566 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 567 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 568 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 569 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 570 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 571 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 572 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 573 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 574 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 575 576 /* Reserved: 0x00F00000 */ 577 /* Legacy compatibility: */ 578 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 579 580 581 /* 582 ** CAPI3REF: Device Characteristics 583 ** 584 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 585 ** object returns an integer which is a vector of these 586 ** bit values expressing I/O characteristics of the mass storage 587 ** device that holds the file that the [sqlite3_io_methods] 588 ** refers to. 589 ** 590 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 591 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 592 ** mean that writes of blocks that are nnn bytes in size and 593 ** are aligned to an address which is an integer multiple of 594 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 595 ** that when data is appended to a file, the data is appended 596 ** first then the size of the file is extended, never the other 597 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 598 ** information is written to disk in the same order as calls 599 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 600 ** after reboot following a crash or power loss, the only bytes in a 601 ** file that were written at the application level might have changed 602 ** and that adjacent bytes, even bytes within the same sector are 603 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 604 ** flag indicates that a file cannot be deleted when open. The 605 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 606 ** read-only media and cannot be changed even by processes with 607 ** elevated privileges. 608 ** 609 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 610 ** filesystem supports doing multiple write operations atomically when those 611 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 612 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 613 */ 614 #define SQLITE_IOCAP_ATOMIC 0x00000001 615 #define SQLITE_IOCAP_ATOMIC512 0x00000002 616 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 617 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 618 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 619 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 620 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 621 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 622 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 623 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 624 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 625 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 626 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 627 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 628 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 629 630 /* 631 ** CAPI3REF: File Locking Levels 632 ** 633 ** SQLite uses one of these integer values as the second 634 ** argument to calls it makes to the xLock() and xUnlock() methods 635 ** of an [sqlite3_io_methods] object. 636 */ 637 #define SQLITE_LOCK_NONE 0 638 #define SQLITE_LOCK_SHARED 1 639 #define SQLITE_LOCK_RESERVED 2 640 #define SQLITE_LOCK_PENDING 3 641 #define SQLITE_LOCK_EXCLUSIVE 4 642 643 /* 644 ** CAPI3REF: Synchronization Type Flags 645 ** 646 ** When SQLite invokes the xSync() method of an 647 ** [sqlite3_io_methods] object it uses a combination of 648 ** these integer values as the second argument. 649 ** 650 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 651 ** sync operation only needs to flush data to mass storage. Inode 652 ** information need not be flushed. If the lower four bits of the flag 653 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 654 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 655 ** to use Mac OS X style fullsync instead of fsync(). 656 ** 657 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 658 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 659 ** settings. The [synchronous pragma] determines when calls to the 660 ** xSync VFS method occur and applies uniformly across all platforms. 661 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 662 ** energetic or rigorous or forceful the sync operations are and 663 ** only make a difference on Mac OSX for the default SQLite code. 664 ** (Third-party VFS implementations might also make the distinction 665 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 666 ** operating systems natively supported by SQLite, only Mac OSX 667 ** cares about the difference.) 668 */ 669 #define SQLITE_SYNC_NORMAL 0x00002 670 #define SQLITE_SYNC_FULL 0x00003 671 #define SQLITE_SYNC_DATAONLY 0x00010 672 673 /* 674 ** CAPI3REF: OS Interface Open File Handle 675 ** 676 ** An [sqlite3_file] object represents an open file in the 677 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 678 ** implementations will 679 ** want to subclass this object by appending additional fields 680 ** for their own use. The pMethods entry is a pointer to an 681 ** [sqlite3_io_methods] object that defines methods for performing 682 ** I/O operations on the open file. 683 */ 684 typedef struct sqlite3_file sqlite3_file; 685 struct sqlite3_file { 686 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 687 }; 688 689 /* 690 ** CAPI3REF: OS Interface File Virtual Methods Object 691 ** 692 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 693 ** [sqlite3_file] object (or, more commonly, a subclass of the 694 ** [sqlite3_file] object) with a pointer to an instance of this object. 695 ** This object defines the methods used to perform various operations 696 ** against the open file represented by the [sqlite3_file] object. 697 ** 698 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 699 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 700 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 701 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 702 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 703 ** to NULL. 704 ** 705 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 706 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 707 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 708 ** flag may be ORed in to indicate that only the data of the file 709 ** and not its inode needs to be synced. 710 ** 711 ** The integer values to xLock() and xUnlock() are one of 712 ** <ul> 713 ** <li> [SQLITE_LOCK_NONE], 714 ** <li> [SQLITE_LOCK_SHARED], 715 ** <li> [SQLITE_LOCK_RESERVED], 716 ** <li> [SQLITE_LOCK_PENDING], or 717 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 718 ** </ul> 719 ** xLock() increases the lock. xUnlock() decreases the lock. 720 ** The xCheckReservedLock() method checks whether any database connection, 721 ** either in this process or in some other process, is holding a RESERVED, 722 ** PENDING, or EXCLUSIVE lock on the file. It returns true 723 ** if such a lock exists and false otherwise. 724 ** 725 ** The xFileControl() method is a generic interface that allows custom 726 ** VFS implementations to directly control an open file using the 727 ** [sqlite3_file_control()] interface. The second "op" argument is an 728 ** integer opcode. The third argument is a generic pointer intended to 729 ** point to a structure that may contain arguments or space in which to 730 ** write return values. Potential uses for xFileControl() might be 731 ** functions to enable blocking locks with timeouts, to change the 732 ** locking strategy (for example to use dot-file locks), to inquire 733 ** about the status of a lock, or to break stale locks. The SQLite 734 ** core reserves all opcodes less than 100 for its own use. 735 ** A [file control opcodes | list of opcodes] less than 100 is available. 736 ** Applications that define a custom xFileControl method should use opcodes 737 ** greater than 100 to avoid conflicts. VFS implementations should 738 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 739 ** recognize. 740 ** 741 ** The xSectorSize() method returns the sector size of the 742 ** device that underlies the file. The sector size is the 743 ** minimum write that can be performed without disturbing 744 ** other bytes in the file. The xDeviceCharacteristics() 745 ** method returns a bit vector describing behaviors of the 746 ** underlying device: 747 ** 748 ** <ul> 749 ** <li> [SQLITE_IOCAP_ATOMIC] 750 ** <li> [SQLITE_IOCAP_ATOMIC512] 751 ** <li> [SQLITE_IOCAP_ATOMIC1K] 752 ** <li> [SQLITE_IOCAP_ATOMIC2K] 753 ** <li> [SQLITE_IOCAP_ATOMIC4K] 754 ** <li> [SQLITE_IOCAP_ATOMIC8K] 755 ** <li> [SQLITE_IOCAP_ATOMIC16K] 756 ** <li> [SQLITE_IOCAP_ATOMIC32K] 757 ** <li> [SQLITE_IOCAP_ATOMIC64K] 758 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 759 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 760 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 761 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 762 ** <li> [SQLITE_IOCAP_IMMUTABLE] 763 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 764 ** </ul> 765 ** 766 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 767 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 768 ** mean that writes of blocks that are nnn bytes in size and 769 ** are aligned to an address which is an integer multiple of 770 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 771 ** that when data is appended to a file, the data is appended 772 ** first then the size of the file is extended, never the other 773 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 774 ** information is written to disk in the same order as calls 775 ** to xWrite(). 776 ** 777 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 778 ** in the unread portions of the buffer with zeros. A VFS that 779 ** fails to zero-fill short reads might seem to work. However, 780 ** failure to zero-fill short reads will eventually lead to 781 ** database corruption. 782 */ 783 typedef struct sqlite3_io_methods sqlite3_io_methods; 784 struct sqlite3_io_methods { 785 int iVersion; 786 int (*xClose)(sqlite3_file*); 787 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 788 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 789 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 790 int (*xSync)(sqlite3_file*, int flags); 791 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 792 int (*xLock)(sqlite3_file*, int); 793 int (*xUnlock)(sqlite3_file*, int); 794 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 795 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 796 int (*xSectorSize)(sqlite3_file*); 797 int (*xDeviceCharacteristics)(sqlite3_file*); 798 /* Methods above are valid for version 1 */ 799 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 800 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 801 void (*xShmBarrier)(sqlite3_file*); 802 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 803 /* Methods above are valid for version 2 */ 804 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 805 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 806 /* Methods above are valid for version 3 */ 807 /* Additional methods may be added in future releases */ 808 }; 809 810 /* 811 ** CAPI3REF: Standard File Control Opcodes 812 ** KEYWORDS: {file control opcodes} {file control opcode} 813 ** 814 ** These integer constants are opcodes for the xFileControl method 815 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 816 ** interface. 817 ** 818 ** <ul> 819 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 820 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 821 ** opcode causes the xFileControl method to write the current state of 822 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 823 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 824 ** into an integer that the pArg argument points to. This capability 825 ** is used during testing and is only available when the SQLITE_TEST 826 ** compile-time option is used. 827 ** 828 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 829 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 830 ** layer a hint of how large the database file will grow to be during the 831 ** current transaction. This hint is not guaranteed to be accurate but it 832 ** is often close. The underlying VFS might choose to preallocate database 833 ** file space based on this hint in order to help writes to the database 834 ** file run faster. 835 ** 836 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 837 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 838 ** implements [sqlite3_deserialize()] to set an upper bound on the size 839 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 840 ** If the integer pointed to is negative, then it is filled in with the 841 ** current limit. Otherwise the limit is set to the larger of the value 842 ** of the integer pointed to and the current database size. The integer 843 ** pointed to is set to the new limit. 844 ** 845 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 846 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 847 ** extends and truncates the database file in chunks of a size specified 848 ** by the user. The fourth argument to [sqlite3_file_control()] should 849 ** point to an integer (type int) containing the new chunk-size to use 850 ** for the nominated database. Allocating database file space in large 851 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 852 ** improve performance on some systems. 853 ** 854 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 855 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 856 ** to the [sqlite3_file] object associated with a particular database 857 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 858 ** 859 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 860 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 861 ** to the [sqlite3_file] object associated with the journal file (either 862 ** the [rollback journal] or the [write-ahead log]) for a particular database 863 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 864 ** 865 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 866 ** No longer in use. 867 ** 868 ** <li>[[SQLITE_FCNTL_SYNC]] 869 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 870 ** sent to the VFS immediately before the xSync method is invoked on a 871 ** database file descriptor. Or, if the xSync method is not invoked 872 ** because the user has configured SQLite with 873 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 874 ** of the xSync method. In most cases, the pointer argument passed with 875 ** this file-control is NULL. However, if the database file is being synced 876 ** as part of a multi-database commit, the argument points to a nul-terminated 877 ** string containing the transactions super-journal file name. VFSes that 878 ** do not need this signal should silently ignore this opcode. Applications 879 ** should not call [sqlite3_file_control()] with this opcode as doing so may 880 ** disrupt the operation of the specialized VFSes that do require it. 881 ** 882 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 883 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 884 ** and sent to the VFS after a transaction has been committed immediately 885 ** but before the database is unlocked. VFSes that do not need this signal 886 ** should silently ignore this opcode. Applications should not call 887 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 888 ** operation of the specialized VFSes that do require it. 889 ** 890 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 891 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 892 ** retry counts and intervals for certain disk I/O operations for the 893 ** windows [VFS] in order to provide robustness in the presence of 894 ** anti-virus programs. By default, the windows VFS will retry file read, 895 ** file write, and file delete operations up to 10 times, with a delay 896 ** of 25 milliseconds before the first retry and with the delay increasing 897 ** by an additional 25 milliseconds with each subsequent retry. This 898 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 899 ** to be adjusted. The values are changed for all database connections 900 ** within the same process. The argument is a pointer to an array of two 901 ** integers where the first integer is the new retry count and the second 902 ** integer is the delay. If either integer is negative, then the setting 903 ** is not changed but instead the prior value of that setting is written 904 ** into the array entry, allowing the current retry settings to be 905 ** interrogated. The zDbName parameter is ignored. 906 ** 907 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 908 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 909 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 910 ** write ahead log ([WAL file]) and shared memory 911 ** files used for transaction control 912 ** are automatically deleted when the latest connection to the database 913 ** closes. Setting persistent WAL mode causes those files to persist after 914 ** close. Persisting the files is useful when other processes that do not 915 ** have write permission on the directory containing the database file want 916 ** to read the database file, as the WAL and shared memory files must exist 917 ** in order for the database to be readable. The fourth parameter to 918 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 919 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 920 ** WAL mode. If the integer is -1, then it is overwritten with the current 921 ** WAL persistence setting. 922 ** 923 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 924 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 925 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 926 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 927 ** xDeviceCharacteristics methods. The fourth parameter to 928 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 929 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 930 ** mode. If the integer is -1, then it is overwritten with the current 931 ** zero-damage mode setting. 932 ** 933 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 934 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 935 ** a write transaction to indicate that, unless it is rolled back for some 936 ** reason, the entire database file will be overwritten by the current 937 ** transaction. This is used by VACUUM operations. 938 ** 939 ** <li>[[SQLITE_FCNTL_VFSNAME]] 940 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 941 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 942 ** final bottom-level VFS are written into memory obtained from 943 ** [sqlite3_malloc()] and the result is stored in the char* variable 944 ** that the fourth parameter of [sqlite3_file_control()] points to. 945 ** The caller is responsible for freeing the memory when done. As with 946 ** all file-control actions, there is no guarantee that this will actually 947 ** do anything. Callers should initialize the char* variable to a NULL 948 ** pointer in case this file-control is not implemented. This file-control 949 ** is intended for diagnostic use only. 950 ** 951 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 952 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 953 ** [VFSes] currently in use. ^(The argument X in 954 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 955 ** of type "[sqlite3_vfs] **". This opcodes will set *X 956 ** to a pointer to the top-level VFS.)^ 957 ** ^When there are multiple VFS shims in the stack, this opcode finds the 958 ** upper-most shim only. 959 ** 960 ** <li>[[SQLITE_FCNTL_PRAGMA]] 961 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 962 ** file control is sent to the open [sqlite3_file] object corresponding 963 ** to the database file to which the pragma statement refers. ^The argument 964 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 965 ** pointers to strings (char**) in which the second element of the array 966 ** is the name of the pragma and the third element is the argument to the 967 ** pragma or NULL if the pragma has no argument. ^The handler for an 968 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 969 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 970 ** or the equivalent and that string will become the result of the pragma or 971 ** the error message if the pragma fails. ^If the 972 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 973 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 974 ** file control returns [SQLITE_OK], then the parser assumes that the 975 ** VFS has handled the PRAGMA itself and the parser generates a no-op 976 ** prepared statement if result string is NULL, or that returns a copy 977 ** of the result string if the string is non-NULL. 978 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 979 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 980 ** that the VFS encountered an error while handling the [PRAGMA] and the 981 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 982 ** file control occurs at the beginning of pragma statement analysis and so 983 ** it is able to override built-in [PRAGMA] statements. 984 ** 985 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 986 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 987 ** file-control may be invoked by SQLite on the database file handle 988 ** shortly after it is opened in order to provide a custom VFS with access 989 ** to the connection's busy-handler callback. The argument is of type (void**) 990 ** - an array of two (void *) values. The first (void *) actually points 991 ** to a function of type (int (*)(void *)). In order to invoke the connection's 992 ** busy-handler, this function should be invoked with the second (void *) in 993 ** the array as the only argument. If it returns non-zero, then the operation 994 ** should be retried. If it returns zero, the custom VFS should abandon the 995 ** current operation. 996 ** 997 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 998 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 999 ** to have SQLite generate a 1000 ** temporary filename using the same algorithm that is followed to generate 1001 ** temporary filenames for TEMP tables and other internal uses. The 1002 ** argument should be a char** which will be filled with the filename 1003 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1004 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1005 ** 1006 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1007 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1008 ** maximum number of bytes that will be used for memory-mapped I/O. 1009 ** The argument is a pointer to a value of type sqlite3_int64 that 1010 ** is an advisory maximum number of bytes in the file to memory map. The 1011 ** pointer is overwritten with the old value. The limit is not changed if 1012 ** the value originally pointed to is negative, and so the current limit 1013 ** can be queried by passing in a pointer to a negative number. This 1014 ** file-control is used internally to implement [PRAGMA mmap_size]. 1015 ** 1016 ** <li>[[SQLITE_FCNTL_TRACE]] 1017 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1018 ** to the VFS about what the higher layers of the SQLite stack are doing. 1019 ** This file control is used by some VFS activity tracing [shims]. 1020 ** The argument is a zero-terminated string. Higher layers in the 1021 ** SQLite stack may generate instances of this file control if 1022 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1023 ** 1024 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1025 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1026 ** pointer to an integer and it writes a boolean into that integer depending 1027 ** on whether or not the file has been renamed, moved, or deleted since it 1028 ** was first opened. 1029 ** 1030 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1031 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1032 ** underlying native file handle associated with a file handle. This file 1033 ** control interprets its argument as a pointer to a native file handle and 1034 ** writes the resulting value there. 1035 ** 1036 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1037 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1038 ** opcode causes the xFileControl method to swap the file handle with the one 1039 ** pointed to by the pArg argument. This capability is used during testing 1040 ** and only needs to be supported when SQLITE_TEST is defined. 1041 ** 1042 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1043 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1044 ** be advantageous to block on the next WAL lock if the lock is not immediately 1045 ** available. The WAL subsystem issues this signal during rare 1046 ** circumstances in order to fix a problem with priority inversion. 1047 ** Applications should <em>not</em> use this file-control. 1048 ** 1049 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1050 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1051 ** VFS should return SQLITE_NOTFOUND for this opcode. 1052 ** 1053 ** <li>[[SQLITE_FCNTL_RBU]] 1054 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1055 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1056 ** this opcode. 1057 ** 1058 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1059 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1060 ** the file descriptor is placed in "batch write mode", which 1061 ** means all subsequent write operations will be deferred and done 1062 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1063 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1064 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1065 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1066 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1067 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1068 ** except for calls to the xWrite method and the xFileControl method 1069 ** with [SQLITE_FCNTL_SIZE_HINT]. 1070 ** 1071 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1072 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1073 ** operations since the previous successful call to 1074 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1075 ** This file control returns [SQLITE_OK] if and only if the writes were 1076 ** all performed successfully and have been committed to persistent storage. 1077 ** ^Regardless of whether or not it is successful, this file control takes 1078 ** the file descriptor out of batch write mode so that all subsequent 1079 ** write operations are independent. 1080 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1081 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1082 ** 1083 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1084 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1085 ** operations since the previous successful call to 1086 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1087 ** ^This file control takes the file descriptor out of batch write mode 1088 ** so that all subsequent write operations are independent. 1089 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1090 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1091 ** 1092 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1093 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1094 ** to block for up to M milliseconds before failing when attempting to 1095 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1096 ** The parameter is a pointer to a 32-bit signed integer that contains 1097 ** the value that M is to be set to. Before returning, the 32-bit signed 1098 ** integer is overwritten with the previous value of M. 1099 ** 1100 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1101 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1102 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1103 ** The "data version" for the pager is written into the pointer. The 1104 ** "data version" changes whenever any change occurs to the corresponding 1105 ** database file, either through SQL statements on the same database 1106 ** connection or through transactions committed by separate database 1107 ** connections possibly in other processes. The [sqlite3_total_changes()] 1108 ** interface can be used to find if any database on the connection has changed, 1109 ** but that interface responds to changes on TEMP as well as MAIN and does 1110 ** not provide a mechanism to detect changes to MAIN only. Also, the 1111 ** [sqlite3_total_changes()] interface responds to internal changes only and 1112 ** omits changes made by other database connections. The 1113 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1114 ** a single attached database that occur due to other database connections, 1115 ** but omits changes implemented by the database connection on which it is 1116 ** called. This file control is the only mechanism to detect changes that 1117 ** happen either internally or externally and that are associated with 1118 ** a particular attached database. 1119 ** 1120 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1121 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1122 ** in wal mode before the client starts to copy pages from the wal 1123 ** file to the database file. 1124 ** 1125 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1126 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1127 ** in wal mode after the client has finished copying pages from the wal 1128 ** file to the database file, but before the *-shm file is updated to 1129 ** record the fact that the pages have been checkpointed. 1130 ** </ul> 1131 */ 1132 #define SQLITE_FCNTL_LOCKSTATE 1 1133 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1134 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1135 #define SQLITE_FCNTL_LAST_ERRNO 4 1136 #define SQLITE_FCNTL_SIZE_HINT 5 1137 #define SQLITE_FCNTL_CHUNK_SIZE 6 1138 #define SQLITE_FCNTL_FILE_POINTER 7 1139 #define SQLITE_FCNTL_SYNC_OMITTED 8 1140 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1141 #define SQLITE_FCNTL_PERSIST_WAL 10 1142 #define SQLITE_FCNTL_OVERWRITE 11 1143 #define SQLITE_FCNTL_VFSNAME 12 1144 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1145 #define SQLITE_FCNTL_PRAGMA 14 1146 #define SQLITE_FCNTL_BUSYHANDLER 15 1147 #define SQLITE_FCNTL_TEMPFILENAME 16 1148 #define SQLITE_FCNTL_MMAP_SIZE 18 1149 #define SQLITE_FCNTL_TRACE 19 1150 #define SQLITE_FCNTL_HAS_MOVED 20 1151 #define SQLITE_FCNTL_SYNC 21 1152 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1153 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1154 #define SQLITE_FCNTL_WAL_BLOCK 24 1155 #define SQLITE_FCNTL_ZIPVFS 25 1156 #define SQLITE_FCNTL_RBU 26 1157 #define SQLITE_FCNTL_VFS_POINTER 27 1158 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1159 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1160 #define SQLITE_FCNTL_PDB 30 1161 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1162 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1163 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1164 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1165 #define SQLITE_FCNTL_DATA_VERSION 35 1166 #define SQLITE_FCNTL_SIZE_LIMIT 36 1167 #define SQLITE_FCNTL_CKPT_DONE 37 1168 #define SQLITE_FCNTL_RESERVE_BYTES 38 1169 #define SQLITE_FCNTL_CKPT_START 39 1170 1171 /* deprecated names */ 1172 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1173 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1174 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1175 1176 1177 /* 1178 ** CAPI3REF: Mutex Handle 1179 ** 1180 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1181 ** abstract type for a mutex object. The SQLite core never looks 1182 ** at the internal representation of an [sqlite3_mutex]. It only 1183 ** deals with pointers to the [sqlite3_mutex] object. 1184 ** 1185 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1186 */ 1187 typedef struct sqlite3_mutex sqlite3_mutex; 1188 1189 /* 1190 ** CAPI3REF: Loadable Extension Thunk 1191 ** 1192 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1193 ** the third parameter to entry points of [loadable extensions]. This 1194 ** structure must be typedefed in order to work around compiler warnings 1195 ** on some platforms. 1196 */ 1197 typedef struct sqlite3_api_routines sqlite3_api_routines; 1198 1199 /* 1200 ** CAPI3REF: OS Interface Object 1201 ** 1202 ** An instance of the sqlite3_vfs object defines the interface between 1203 ** the SQLite core and the underlying operating system. The "vfs" 1204 ** in the name of the object stands for "virtual file system". See 1205 ** the [VFS | VFS documentation] for further information. 1206 ** 1207 ** The VFS interface is sometimes extended by adding new methods onto 1208 ** the end. Each time such an extension occurs, the iVersion field 1209 ** is incremented. The iVersion value started out as 1 in 1210 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1211 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1212 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1213 ** may be appended to the sqlite3_vfs object and the iVersion value 1214 ** may increase again in future versions of SQLite. 1215 ** Note that due to an oversight, the structure 1216 ** of the sqlite3_vfs object changed in the transition from 1217 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1218 ** and yet the iVersion field was not increased. 1219 ** 1220 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1221 ** structure used by this VFS. mxPathname is the maximum length of 1222 ** a pathname in this VFS. 1223 ** 1224 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1225 ** the pNext pointer. The [sqlite3_vfs_register()] 1226 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1227 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1228 ** searches the list. Neither the application code nor the VFS 1229 ** implementation should use the pNext pointer. 1230 ** 1231 ** The pNext field is the only field in the sqlite3_vfs 1232 ** structure that SQLite will ever modify. SQLite will only access 1233 ** or modify this field while holding a particular static mutex. 1234 ** The application should never modify anything within the sqlite3_vfs 1235 ** object once the object has been registered. 1236 ** 1237 ** The zName field holds the name of the VFS module. The name must 1238 ** be unique across all VFS modules. 1239 ** 1240 ** [[sqlite3_vfs.xOpen]] 1241 ** ^SQLite guarantees that the zFilename parameter to xOpen 1242 ** is either a NULL pointer or string obtained 1243 ** from xFullPathname() with an optional suffix added. 1244 ** ^If a suffix is added to the zFilename parameter, it will 1245 ** consist of a single "-" character followed by no more than 1246 ** 11 alphanumeric and/or "-" characters. 1247 ** ^SQLite further guarantees that 1248 ** the string will be valid and unchanged until xClose() is 1249 ** called. Because of the previous sentence, 1250 ** the [sqlite3_file] can safely store a pointer to the 1251 ** filename if it needs to remember the filename for some reason. 1252 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1253 ** must invent its own temporary name for the file. ^Whenever the 1254 ** xFilename parameter is NULL it will also be the case that the 1255 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1256 ** 1257 ** The flags argument to xOpen() includes all bits set in 1258 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1259 ** or [sqlite3_open16()] is used, then flags includes at least 1260 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1261 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1262 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1263 ** 1264 ** ^(SQLite will also add one of the following flags to the xOpen() 1265 ** call, depending on the object being opened: 1266 ** 1267 ** <ul> 1268 ** <li> [SQLITE_OPEN_MAIN_DB] 1269 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1270 ** <li> [SQLITE_OPEN_TEMP_DB] 1271 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1272 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1273 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1274 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1275 ** <li> [SQLITE_OPEN_WAL] 1276 ** </ul>)^ 1277 ** 1278 ** The file I/O implementation can use the object type flags to 1279 ** change the way it deals with files. For example, an application 1280 ** that does not care about crash recovery or rollback might make 1281 ** the open of a journal file a no-op. Writes to this journal would 1282 ** also be no-ops, and any attempt to read the journal would return 1283 ** SQLITE_IOERR. Or the implementation might recognize that a database 1284 ** file will be doing page-aligned sector reads and writes in a random 1285 ** order and set up its I/O subsystem accordingly. 1286 ** 1287 ** SQLite might also add one of the following flags to the xOpen method: 1288 ** 1289 ** <ul> 1290 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1291 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1292 ** </ul> 1293 ** 1294 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1295 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1296 ** will be set for TEMP databases and their journals, transient 1297 ** databases, and subjournals. 1298 ** 1299 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1300 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1301 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1302 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1303 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1304 ** be created, and that it is an error if it already exists. 1305 ** It is <i>not</i> used to indicate the file should be opened 1306 ** for exclusive access. 1307 ** 1308 ** ^At least szOsFile bytes of memory are allocated by SQLite 1309 ** to hold the [sqlite3_file] structure passed as the third 1310 ** argument to xOpen. The xOpen method does not have to 1311 ** allocate the structure; it should just fill it in. Note that 1312 ** the xOpen method must set the sqlite3_file.pMethods to either 1313 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1314 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1315 ** element will be valid after xOpen returns regardless of the success 1316 ** or failure of the xOpen call. 1317 ** 1318 ** [[sqlite3_vfs.xAccess]] 1319 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1320 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1321 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1322 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1323 ** flag is never actually used and is not implemented in the built-in 1324 ** VFSes of SQLite. The file is named by the second argument and can be a 1325 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1326 ** non-zero error code if there is an I/O error or if the name of 1327 ** the file given in the second argument is illegal. If SQLITE_OK 1328 ** is returned, then non-zero or zero is written into *pResOut to indicate 1329 ** whether or not the file is accessible. 1330 ** 1331 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1332 ** output buffer xFullPathname. The exact size of the output buffer 1333 ** is also passed as a parameter to both methods. If the output buffer 1334 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1335 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1336 ** to prevent this by setting mxPathname to a sufficiently large value. 1337 ** 1338 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1339 ** interfaces are not strictly a part of the filesystem, but they are 1340 ** included in the VFS structure for completeness. 1341 ** The xRandomness() function attempts to return nBytes bytes 1342 ** of good-quality randomness into zOut. The return value is 1343 ** the actual number of bytes of randomness obtained. 1344 ** The xSleep() method causes the calling thread to sleep for at 1345 ** least the number of microseconds given. ^The xCurrentTime() 1346 ** method returns a Julian Day Number for the current date and time as 1347 ** a floating point value. 1348 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1349 ** Day Number multiplied by 86400000 (the number of milliseconds in 1350 ** a 24-hour day). 1351 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1352 ** date and time if that method is available (if iVersion is 2 or 1353 ** greater and the function pointer is not NULL) and will fall back 1354 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1355 ** 1356 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1357 ** are not used by the SQLite core. These optional interfaces are provided 1358 ** by some VFSes to facilitate testing of the VFS code. By overriding 1359 ** system calls with functions under its control, a test program can 1360 ** simulate faults and error conditions that would otherwise be difficult 1361 ** or impossible to induce. The set of system calls that can be overridden 1362 ** varies from one VFS to another, and from one version of the same VFS to the 1363 ** next. Applications that use these interfaces must be prepared for any 1364 ** or all of these interfaces to be NULL or for their behavior to change 1365 ** from one release to the next. Applications must not attempt to access 1366 ** any of these methods if the iVersion of the VFS is less than 3. 1367 */ 1368 typedef struct sqlite3_vfs sqlite3_vfs; 1369 typedef void (*sqlite3_syscall_ptr)(void); 1370 struct sqlite3_vfs { 1371 int iVersion; /* Structure version number (currently 3) */ 1372 int szOsFile; /* Size of subclassed sqlite3_file */ 1373 int mxPathname; /* Maximum file pathname length */ 1374 sqlite3_vfs *pNext; /* Next registered VFS */ 1375 const char *zName; /* Name of this virtual file system */ 1376 void *pAppData; /* Pointer to application-specific data */ 1377 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1378 int flags, int *pOutFlags); 1379 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1380 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1381 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1382 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1383 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1384 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1385 void (*xDlClose)(sqlite3_vfs*, void*); 1386 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1387 int (*xSleep)(sqlite3_vfs*, int microseconds); 1388 int (*xCurrentTime)(sqlite3_vfs*, double*); 1389 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1390 /* 1391 ** The methods above are in version 1 of the sqlite_vfs object 1392 ** definition. Those that follow are added in version 2 or later 1393 */ 1394 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1395 /* 1396 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1397 ** Those below are for version 3 and greater. 1398 */ 1399 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1400 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1401 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1402 /* 1403 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1404 ** New fields may be appended in future versions. The iVersion 1405 ** value will increment whenever this happens. 1406 */ 1407 }; 1408 1409 /* 1410 ** CAPI3REF: Flags for the xAccess VFS method 1411 ** 1412 ** These integer constants can be used as the third parameter to 1413 ** the xAccess method of an [sqlite3_vfs] object. They determine 1414 ** what kind of permissions the xAccess method is looking for. 1415 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1416 ** simply checks whether the file exists. 1417 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1418 ** checks whether the named directory is both readable and writable 1419 ** (in other words, if files can be added, removed, and renamed within 1420 ** the directory). 1421 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1422 ** [temp_store_directory pragma], though this could change in a future 1423 ** release of SQLite. 1424 ** With SQLITE_ACCESS_READ, the xAccess method 1425 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1426 ** currently unused, though it might be used in a future release of 1427 ** SQLite. 1428 */ 1429 #define SQLITE_ACCESS_EXISTS 0 1430 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1431 #define SQLITE_ACCESS_READ 2 /* Unused */ 1432 1433 /* 1434 ** CAPI3REF: Flags for the xShmLock VFS method 1435 ** 1436 ** These integer constants define the various locking operations 1437 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1438 ** following are the only legal combinations of flags to the 1439 ** xShmLock method: 1440 ** 1441 ** <ul> 1442 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1443 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1444 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1445 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1446 ** </ul> 1447 ** 1448 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1449 ** was given on the corresponding lock. 1450 ** 1451 ** The xShmLock method can transition between unlocked and SHARED or 1452 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1453 ** and EXCLUSIVE. 1454 */ 1455 #define SQLITE_SHM_UNLOCK 1 1456 #define SQLITE_SHM_LOCK 2 1457 #define SQLITE_SHM_SHARED 4 1458 #define SQLITE_SHM_EXCLUSIVE 8 1459 1460 /* 1461 ** CAPI3REF: Maximum xShmLock index 1462 ** 1463 ** The xShmLock method on [sqlite3_io_methods] may use values 1464 ** between 0 and this upper bound as its "offset" argument. 1465 ** The SQLite core will never attempt to acquire or release a 1466 ** lock outside of this range 1467 */ 1468 #define SQLITE_SHM_NLOCK 8 1469 1470 1471 /* 1472 ** CAPI3REF: Initialize The SQLite Library 1473 ** 1474 ** ^The sqlite3_initialize() routine initializes the 1475 ** SQLite library. ^The sqlite3_shutdown() routine 1476 ** deallocates any resources that were allocated by sqlite3_initialize(). 1477 ** These routines are designed to aid in process initialization and 1478 ** shutdown on embedded systems. Workstation applications using 1479 ** SQLite normally do not need to invoke either of these routines. 1480 ** 1481 ** A call to sqlite3_initialize() is an "effective" call if it is 1482 ** the first time sqlite3_initialize() is invoked during the lifetime of 1483 ** the process, or if it is the first time sqlite3_initialize() is invoked 1484 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1485 ** of sqlite3_initialize() does any initialization. All other calls 1486 ** are harmless no-ops.)^ 1487 ** 1488 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1489 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1490 ** an effective call to sqlite3_shutdown() does any deinitialization. 1491 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1492 ** 1493 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1494 ** is not. The sqlite3_shutdown() interface must only be called from a 1495 ** single thread. All open [database connections] must be closed and all 1496 ** other SQLite resources must be deallocated prior to invoking 1497 ** sqlite3_shutdown(). 1498 ** 1499 ** Among other things, ^sqlite3_initialize() will invoke 1500 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1501 ** will invoke sqlite3_os_end(). 1502 ** 1503 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1504 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1505 ** the library (perhaps it is unable to allocate a needed resource such 1506 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1507 ** 1508 ** ^The sqlite3_initialize() routine is called internally by many other 1509 ** SQLite interfaces so that an application usually does not need to 1510 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1511 ** calls sqlite3_initialize() so the SQLite library will be automatically 1512 ** initialized when [sqlite3_open()] is called if it has not be initialized 1513 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1514 ** compile-time option, then the automatic calls to sqlite3_initialize() 1515 ** are omitted and the application must call sqlite3_initialize() directly 1516 ** prior to using any other SQLite interface. For maximum portability, 1517 ** it is recommended that applications always invoke sqlite3_initialize() 1518 ** directly prior to using any other SQLite interface. Future releases 1519 ** of SQLite may require this. In other words, the behavior exhibited 1520 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1521 ** default behavior in some future release of SQLite. 1522 ** 1523 ** The sqlite3_os_init() routine does operating-system specific 1524 ** initialization of the SQLite library. The sqlite3_os_end() 1525 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1526 ** performed by these routines include allocation or deallocation 1527 ** of static resources, initialization of global variables, 1528 ** setting up a default [sqlite3_vfs] module, or setting up 1529 ** a default configuration using [sqlite3_config()]. 1530 ** 1531 ** The application should never invoke either sqlite3_os_init() 1532 ** or sqlite3_os_end() directly. The application should only invoke 1533 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1534 ** interface is called automatically by sqlite3_initialize() and 1535 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1536 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1537 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1538 ** When [custom builds | built for other platforms] 1539 ** (using the [SQLITE_OS_OTHER=1] compile-time 1540 ** option) the application must supply a suitable implementation for 1541 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1542 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1543 ** must return [SQLITE_OK] on success and some other [error code] upon 1544 ** failure. 1545 */ 1546 SQLITE_API int sqlite3_initialize(void); 1547 SQLITE_API int sqlite3_shutdown(void); 1548 SQLITE_API int sqlite3_os_init(void); 1549 SQLITE_API int sqlite3_os_end(void); 1550 1551 /* 1552 ** CAPI3REF: Configuring The SQLite Library 1553 ** 1554 ** The sqlite3_config() interface is used to make global configuration 1555 ** changes to SQLite in order to tune SQLite to the specific needs of 1556 ** the application. The default configuration is recommended for most 1557 ** applications and so this routine is usually not necessary. It is 1558 ** provided to support rare applications with unusual needs. 1559 ** 1560 ** <b>The sqlite3_config() interface is not threadsafe. The application 1561 ** must ensure that no other SQLite interfaces are invoked by other 1562 ** threads while sqlite3_config() is running.</b> 1563 ** 1564 ** The sqlite3_config() interface 1565 ** may only be invoked prior to library initialization using 1566 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1567 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1568 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1569 ** Note, however, that ^sqlite3_config() can be called as part of the 1570 ** implementation of an application-defined [sqlite3_os_init()]. 1571 ** 1572 ** The first argument to sqlite3_config() is an integer 1573 ** [configuration option] that determines 1574 ** what property of SQLite is to be configured. Subsequent arguments 1575 ** vary depending on the [configuration option] 1576 ** in the first argument. 1577 ** 1578 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1579 ** ^If the option is unknown or SQLite is unable to set the option 1580 ** then this routine returns a non-zero [error code]. 1581 */ 1582 SQLITE_API int sqlite3_config(int, ...); 1583 1584 /* 1585 ** CAPI3REF: Configure database connections 1586 ** METHOD: sqlite3 1587 ** 1588 ** The sqlite3_db_config() interface is used to make configuration 1589 ** changes to a [database connection]. The interface is similar to 1590 ** [sqlite3_config()] except that the changes apply to a single 1591 ** [database connection] (specified in the first argument). 1592 ** 1593 ** The second argument to sqlite3_db_config(D,V,...) is the 1594 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1595 ** that indicates what aspect of the [database connection] is being configured. 1596 ** Subsequent arguments vary depending on the configuration verb. 1597 ** 1598 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1599 ** the call is considered successful. 1600 */ 1601 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1602 1603 /* 1604 ** CAPI3REF: Memory Allocation Routines 1605 ** 1606 ** An instance of this object defines the interface between SQLite 1607 ** and low-level memory allocation routines. 1608 ** 1609 ** This object is used in only one place in the SQLite interface. 1610 ** A pointer to an instance of this object is the argument to 1611 ** [sqlite3_config()] when the configuration option is 1612 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1613 ** By creating an instance of this object 1614 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1615 ** during configuration, an application can specify an alternative 1616 ** memory allocation subsystem for SQLite to use for all of its 1617 ** dynamic memory needs. 1618 ** 1619 ** Note that SQLite comes with several [built-in memory allocators] 1620 ** that are perfectly adequate for the overwhelming majority of applications 1621 ** and that this object is only useful to a tiny minority of applications 1622 ** with specialized memory allocation requirements. This object is 1623 ** also used during testing of SQLite in order to specify an alternative 1624 ** memory allocator that simulates memory out-of-memory conditions in 1625 ** order to verify that SQLite recovers gracefully from such 1626 ** conditions. 1627 ** 1628 ** The xMalloc, xRealloc, and xFree methods must work like the 1629 ** malloc(), realloc() and free() functions from the standard C library. 1630 ** ^SQLite guarantees that the second argument to 1631 ** xRealloc is always a value returned by a prior call to xRoundup. 1632 ** 1633 ** xSize should return the allocated size of a memory allocation 1634 ** previously obtained from xMalloc or xRealloc. The allocated size 1635 ** is always at least as big as the requested size but may be larger. 1636 ** 1637 ** The xRoundup method returns what would be the allocated size of 1638 ** a memory allocation given a particular requested size. Most memory 1639 ** allocators round up memory allocations at least to the next multiple 1640 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1641 ** Every memory allocation request coming in through [sqlite3_malloc()] 1642 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1643 ** that causes the corresponding memory allocation to fail. 1644 ** 1645 ** The xInit method initializes the memory allocator. For example, 1646 ** it might allocate any required mutexes or initialize internal data 1647 ** structures. The xShutdown method is invoked (indirectly) by 1648 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1649 ** by xInit. The pAppData pointer is used as the only parameter to 1650 ** xInit and xShutdown. 1651 ** 1652 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1653 ** the xInit method, so the xInit method need not be threadsafe. The 1654 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1655 ** not need to be threadsafe either. For all other methods, SQLite 1656 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1657 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1658 ** it is by default) and so the methods are automatically serialized. 1659 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1660 ** methods must be threadsafe or else make their own arrangements for 1661 ** serialization. 1662 ** 1663 ** SQLite will never invoke xInit() more than once without an intervening 1664 ** call to xShutdown(). 1665 */ 1666 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1667 struct sqlite3_mem_methods { 1668 void *(*xMalloc)(int); /* Memory allocation function */ 1669 void (*xFree)(void*); /* Free a prior allocation */ 1670 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1671 int (*xSize)(void*); /* Return the size of an allocation */ 1672 int (*xRoundup)(int); /* Round up request size to allocation size */ 1673 int (*xInit)(void*); /* Initialize the memory allocator */ 1674 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1675 void *pAppData; /* Argument to xInit() and xShutdown() */ 1676 }; 1677 1678 /* 1679 ** CAPI3REF: Configuration Options 1680 ** KEYWORDS: {configuration option} 1681 ** 1682 ** These constants are the available integer configuration options that 1683 ** can be passed as the first argument to the [sqlite3_config()] interface. 1684 ** 1685 ** New configuration options may be added in future releases of SQLite. 1686 ** Existing configuration options might be discontinued. Applications 1687 ** should check the return code from [sqlite3_config()] to make sure that 1688 ** the call worked. The [sqlite3_config()] interface will return a 1689 ** non-zero [error code] if a discontinued or unsupported configuration option 1690 ** is invoked. 1691 ** 1692 ** <dl> 1693 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1694 ** <dd>There are no arguments to this option. ^This option sets the 1695 ** [threading mode] to Single-thread. In other words, it disables 1696 ** all mutexing and puts SQLite into a mode where it can only be used 1697 ** by a single thread. ^If SQLite is compiled with 1698 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1699 ** it is not possible to change the [threading mode] from its default 1700 ** value of Single-thread and so [sqlite3_config()] will return 1701 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1702 ** configuration option.</dd> 1703 ** 1704 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1705 ** <dd>There are no arguments to this option. ^This option sets the 1706 ** [threading mode] to Multi-thread. In other words, it disables 1707 ** mutexing on [database connection] and [prepared statement] objects. 1708 ** The application is responsible for serializing access to 1709 ** [database connections] and [prepared statements]. But other mutexes 1710 ** are enabled so that SQLite will be safe to use in a multi-threaded 1711 ** environment as long as no two threads attempt to use the same 1712 ** [database connection] at the same time. ^If SQLite is compiled with 1713 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1714 ** it is not possible to set the Multi-thread [threading mode] and 1715 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1716 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1717 ** 1718 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1719 ** <dd>There are no arguments to this option. ^This option sets the 1720 ** [threading mode] to Serialized. In other words, this option enables 1721 ** all mutexes including the recursive 1722 ** mutexes on [database connection] and [prepared statement] objects. 1723 ** In this mode (which is the default when SQLite is compiled with 1724 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1725 ** to [database connections] and [prepared statements] so that the 1726 ** application is free to use the same [database connection] or the 1727 ** same [prepared statement] in different threads at the same time. 1728 ** ^If SQLite is compiled with 1729 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1730 ** it is not possible to set the Serialized [threading mode] and 1731 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1732 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1733 ** 1734 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1735 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1736 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1737 ** The argument specifies 1738 ** alternative low-level memory allocation routines to be used in place of 1739 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1740 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1741 ** before the [sqlite3_config()] call returns.</dd> 1742 ** 1743 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1744 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1745 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1746 ** The [sqlite3_mem_methods] 1747 ** structure is filled with the currently defined memory allocation routines.)^ 1748 ** This option can be used to overload the default memory allocation 1749 ** routines with a wrapper that simulations memory allocation failure or 1750 ** tracks memory usage, for example. </dd> 1751 ** 1752 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1753 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1754 ** type int, interpreted as a boolean, which if true provides a hint to 1755 ** SQLite that it should avoid large memory allocations if possible. 1756 ** SQLite will run faster if it is free to make large memory allocations, 1757 ** but some application might prefer to run slower in exchange for 1758 ** guarantees about memory fragmentation that are possible if large 1759 ** allocations are avoided. This hint is normally off. 1760 ** </dd> 1761 ** 1762 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1763 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1764 ** interpreted as a boolean, which enables or disables the collection of 1765 ** memory allocation statistics. ^(When memory allocation statistics are 1766 ** disabled, the following SQLite interfaces become non-operational: 1767 ** <ul> 1768 ** <li> [sqlite3_hard_heap_limit64()] 1769 ** <li> [sqlite3_memory_used()] 1770 ** <li> [sqlite3_memory_highwater()] 1771 ** <li> [sqlite3_soft_heap_limit64()] 1772 ** <li> [sqlite3_status64()] 1773 ** </ul>)^ 1774 ** ^Memory allocation statistics are enabled by default unless SQLite is 1775 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1776 ** allocation statistics are disabled by default. 1777 ** </dd> 1778 ** 1779 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1780 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1781 ** </dd> 1782 ** 1783 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1784 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1785 ** that SQLite can use for the database page cache with the default page 1786 ** cache implementation. 1787 ** This configuration option is a no-op if an application-defined page 1788 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1789 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1790 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1791 ** and the number of cache lines (N). 1792 ** The sz argument should be the size of the largest database page 1793 ** (a power of two between 512 and 65536) plus some extra bytes for each 1794 ** page header. ^The number of extra bytes needed by the page header 1795 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1796 ** ^It is harmless, apart from the wasted memory, 1797 ** for the sz parameter to be larger than necessary. The pMem 1798 ** argument must be either a NULL pointer or a pointer to an 8-byte 1799 ** aligned block of memory of at least sz*N bytes, otherwise 1800 ** subsequent behavior is undefined. 1801 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1802 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1803 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1804 ** is exhausted. 1805 ** ^If pMem is NULL and N is non-zero, then each database connection 1806 ** does an initial bulk allocation for page cache memory 1807 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1808 ** of -1024*N bytes if N is negative, . ^If additional 1809 ** page cache memory is needed beyond what is provided by the initial 1810 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1811 ** additional cache line. </dd> 1812 ** 1813 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1814 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1815 ** that SQLite will use for all of its dynamic memory allocation needs 1816 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1817 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1818 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1819 ** [SQLITE_ERROR] if invoked otherwise. 1820 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1821 ** An 8-byte aligned pointer to the memory, 1822 ** the number of bytes in the memory buffer, and the minimum allocation size. 1823 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1824 ** to using its default memory allocator (the system malloc() implementation), 1825 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1826 ** memory pointer is not NULL then the alternative memory 1827 ** allocator is engaged to handle all of SQLites memory allocation needs. 1828 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1829 ** boundary or subsequent behavior of SQLite will be undefined. 1830 ** The minimum allocation size is capped at 2**12. Reasonable values 1831 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1832 ** 1833 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1834 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1835 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1836 ** The argument specifies alternative low-level mutex routines to be used 1837 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1838 ** the content of the [sqlite3_mutex_methods] structure before the call to 1839 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1840 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1841 ** the entire mutexing subsystem is omitted from the build and hence calls to 1842 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1843 ** return [SQLITE_ERROR].</dd> 1844 ** 1845 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1846 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1847 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1848 ** [sqlite3_mutex_methods] 1849 ** structure is filled with the currently defined mutex routines.)^ 1850 ** This option can be used to overload the default mutex allocation 1851 ** routines with a wrapper used to track mutex usage for performance 1852 ** profiling or testing, for example. ^If SQLite is compiled with 1853 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1854 ** the entire mutexing subsystem is omitted from the build and hence calls to 1855 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1856 ** return [SQLITE_ERROR].</dd> 1857 ** 1858 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1859 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1860 ** the default size of lookaside memory on each [database connection]. 1861 ** The first argument is the 1862 ** size of each lookaside buffer slot and the second is the number of 1863 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1864 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1865 ** option to [sqlite3_db_config()] can be used to change the lookaside 1866 ** configuration on individual connections.)^ </dd> 1867 ** 1868 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1869 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1870 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1871 ** the interface to a custom page cache implementation.)^ 1872 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1873 ** 1874 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1875 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1876 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1877 ** the current page cache implementation into that object.)^ </dd> 1878 ** 1879 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1880 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1881 ** global [error log]. 1882 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1883 ** function with a call signature of void(*)(void*,int,const char*), 1884 ** and a pointer to void. ^If the function pointer is not NULL, it is 1885 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1886 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1887 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1888 ** passed through as the first parameter to the application-defined logger 1889 ** function whenever that function is invoked. ^The second parameter to 1890 ** the logger function is a copy of the first parameter to the corresponding 1891 ** [sqlite3_log()] call and is intended to be a [result code] or an 1892 ** [extended result code]. ^The third parameter passed to the logger is 1893 ** log message after formatting via [sqlite3_snprintf()]. 1894 ** The SQLite logging interface is not reentrant; the logger function 1895 ** supplied by the application must not invoke any SQLite interface. 1896 ** In a multi-threaded application, the application-defined logger 1897 ** function must be threadsafe. </dd> 1898 ** 1899 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1900 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1901 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1902 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1903 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1904 ** [sqlite3_open16()] or 1905 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1906 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1907 ** connection is opened. ^If it is globally disabled, filenames are 1908 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1909 ** database connection is opened. ^(By default, URI handling is globally 1910 ** disabled. The default value may be changed by compiling with the 1911 ** [SQLITE_USE_URI] symbol defined.)^ 1912 ** 1913 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1914 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1915 ** argument which is interpreted as a boolean in order to enable or disable 1916 ** the use of covering indices for full table scans in the query optimizer. 1917 ** ^The default setting is determined 1918 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1919 ** if that compile-time option is omitted. 1920 ** The ability to disable the use of covering indices for full table scans 1921 ** is because some incorrectly coded legacy applications might malfunction 1922 ** when the optimization is enabled. Providing the ability to 1923 ** disable the optimization allows the older, buggy application code to work 1924 ** without change even with newer versions of SQLite. 1925 ** 1926 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1927 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1928 ** <dd> These options are obsolete and should not be used by new code. 1929 ** They are retained for backwards compatibility but are now no-ops. 1930 ** </dd> 1931 ** 1932 ** [[SQLITE_CONFIG_SQLLOG]] 1933 ** <dt>SQLITE_CONFIG_SQLLOG 1934 ** <dd>This option is only available if sqlite is compiled with the 1935 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1936 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1937 ** The second should be of type (void*). The callback is invoked by the library 1938 ** in three separate circumstances, identified by the value passed as the 1939 ** fourth parameter. If the fourth parameter is 0, then the database connection 1940 ** passed as the second argument has just been opened. The third argument 1941 ** points to a buffer containing the name of the main database file. If the 1942 ** fourth parameter is 1, then the SQL statement that the third parameter 1943 ** points to has just been executed. Or, if the fourth parameter is 2, then 1944 ** the connection being passed as the second parameter is being closed. The 1945 ** third parameter is passed NULL In this case. An example of using this 1946 ** configuration option can be seen in the "test_sqllog.c" source file in 1947 ** the canonical SQLite source tree.</dd> 1948 ** 1949 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1950 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1951 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1952 ** that are the default mmap size limit (the default setting for 1953 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1954 ** ^The default setting can be overridden by each database connection using 1955 ** either the [PRAGMA mmap_size] command, or by using the 1956 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1957 ** will be silently truncated if necessary so that it does not exceed the 1958 ** compile-time maximum mmap size set by the 1959 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1960 ** ^If either argument to this option is negative, then that argument is 1961 ** changed to its compile-time default. 1962 ** 1963 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1964 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1965 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1966 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1967 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1968 ** that specifies the maximum size of the created heap. 1969 ** 1970 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1971 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1972 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1973 ** is a pointer to an integer and writes into that integer the number of extra 1974 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1975 ** The amount of extra space required can change depending on the compiler, 1976 ** target platform, and SQLite version. 1977 ** 1978 ** [[SQLITE_CONFIG_PMASZ]] 1979 ** <dt>SQLITE_CONFIG_PMASZ 1980 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1981 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1982 ** sorter to that integer. The default minimum PMA Size is set by the 1983 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1984 ** to help with sort operations when multithreaded sorting 1985 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1986 ** to be sorted exceeds the page size times the minimum of the 1987 ** [PRAGMA cache_size] setting and this value. 1988 ** 1989 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1990 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1991 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1992 ** becomes the [statement journal] spill-to-disk threshold. 1993 ** [Statement journals] are held in memory until their size (in bytes) 1994 ** exceeds this threshold, at which point they are written to disk. 1995 ** Or if the threshold is -1, statement journals are always held 1996 ** exclusively in memory. 1997 ** Since many statement journals never become large, setting the spill 1998 ** threshold to a value such as 64KiB can greatly reduce the amount of 1999 ** I/O required to support statement rollback. 2000 ** The default value for this setting is controlled by the 2001 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2002 ** 2003 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2004 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2005 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2006 ** of type (int) - the new value of the sorter-reference size threshold. 2007 ** Usually, when SQLite uses an external sort to order records according 2008 ** to an ORDER BY clause, all fields required by the caller are present in the 2009 ** sorted records. However, if SQLite determines based on the declared type 2010 ** of a table column that its values are likely to be very large - larger 2011 ** than the configured sorter-reference size threshold - then a reference 2012 ** is stored in each sorted record and the required column values loaded 2013 ** from the database as records are returned in sorted order. The default 2014 ** value for this option is to never use this optimization. Specifying a 2015 ** negative value for this option restores the default behaviour. 2016 ** This option is only available if SQLite is compiled with the 2017 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2018 ** 2019 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2020 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2021 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2022 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2023 ** database created using [sqlite3_deserialize()]. This default maximum 2024 ** size can be adjusted up or down for individual databases using the 2025 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2026 ** configuration setting is never used, then the default maximum is determined 2027 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2028 ** compile-time option is not set, then the default maximum is 1073741824. 2029 ** </dl> 2030 */ 2031 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2032 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2033 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2034 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2035 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2036 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2037 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2038 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2039 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2040 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2041 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2042 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2043 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2044 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2045 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2046 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2047 #define SQLITE_CONFIG_URI 17 /* int */ 2048 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2049 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2050 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2051 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2052 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2053 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2054 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2055 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2056 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2057 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2058 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2059 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2060 2061 /* 2062 ** CAPI3REF: Database Connection Configuration Options 2063 ** 2064 ** These constants are the available integer configuration options that 2065 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2066 ** 2067 ** New configuration options may be added in future releases of SQLite. 2068 ** Existing configuration options might be discontinued. Applications 2069 ** should check the return code from [sqlite3_db_config()] to make sure that 2070 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2071 ** non-zero [error code] if a discontinued or unsupported configuration option 2072 ** is invoked. 2073 ** 2074 ** <dl> 2075 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2076 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2077 ** <dd> ^This option takes three additional arguments that determine the 2078 ** [lookaside memory allocator] configuration for the [database connection]. 2079 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2080 ** pointer to a memory buffer to use for lookaside memory. 2081 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2082 ** may be NULL in which case SQLite will allocate the 2083 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2084 ** size of each lookaside buffer slot. ^The third argument is the number of 2085 ** slots. The size of the buffer in the first argument must be greater than 2086 ** or equal to the product of the second and third arguments. The buffer 2087 ** must be aligned to an 8-byte boundary. ^If the second argument to 2088 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2089 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2090 ** configuration for a database connection can only be changed when that 2091 ** connection is not currently using lookaside memory, or in other words 2092 ** when the "current value" returned by 2093 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2094 ** Any attempt to change the lookaside memory configuration when lookaside 2095 ** memory is in use leaves the configuration unchanged and returns 2096 ** [SQLITE_BUSY].)^</dd> 2097 ** 2098 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2099 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2100 ** <dd> ^This option is used to enable or disable the enforcement of 2101 ** [foreign key constraints]. There should be two additional arguments. 2102 ** The first argument is an integer which is 0 to disable FK enforcement, 2103 ** positive to enable FK enforcement or negative to leave FK enforcement 2104 ** unchanged. The second parameter is a pointer to an integer into which 2105 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2106 ** following this call. The second parameter may be a NULL pointer, in 2107 ** which case the FK enforcement setting is not reported back. </dd> 2108 ** 2109 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2110 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2111 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2112 ** There should be two additional arguments. 2113 ** The first argument is an integer which is 0 to disable triggers, 2114 ** positive to enable triggers or negative to leave the setting unchanged. 2115 ** The second parameter is a pointer to an integer into which 2116 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2117 ** following this call. The second parameter may be a NULL pointer, in 2118 ** which case the trigger setting is not reported back. 2119 ** 2120 ** <p>Originally this option disabled all triggers. ^(However, since 2121 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2122 ** this option is off. So, in other words, this option now only disables 2123 ** triggers in the main database schema or in the schemas of ATTACH-ed 2124 ** databases.)^ </dd> 2125 ** 2126 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2127 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2128 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2129 ** There should be two additional arguments. 2130 ** The first argument is an integer which is 0 to disable views, 2131 ** positive to enable views or negative to leave the setting unchanged. 2132 ** The second parameter is a pointer to an integer into which 2133 ** is written 0 or 1 to indicate whether views are disabled or enabled 2134 ** following this call. The second parameter may be a NULL pointer, in 2135 ** which case the view setting is not reported back. 2136 ** 2137 ** <p>Originally this option disabled all views. ^(However, since 2138 ** SQLite version 3.35.0, TEMP views are still allowed even if 2139 ** this option is off. So, in other words, this option now only disables 2140 ** views in the main database schema or in the schemas of ATTACH-ed 2141 ** databases.)^ </dd> 2142 ** 2143 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2144 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2145 ** <dd> ^This option is used to enable or disable the 2146 ** [fts3_tokenizer()] function which is part of the 2147 ** [FTS3] full-text search engine extension. 2148 ** There should be two additional arguments. 2149 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2150 ** positive to enable fts3_tokenizer() or negative to leave the setting 2151 ** unchanged. 2152 ** The second parameter is a pointer to an integer into which 2153 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2154 ** following this call. The second parameter may be a NULL pointer, in 2155 ** which case the new setting is not reported back. </dd> 2156 ** 2157 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2158 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2159 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2160 ** interface independently of the [load_extension()] SQL function. 2161 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2162 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2163 ** There should be two additional arguments. 2164 ** When the first argument to this interface is 1, then only the C-API is 2165 ** enabled and the SQL function remains disabled. If the first argument to 2166 ** this interface is 0, then both the C-API and the SQL function are disabled. 2167 ** If the first argument is -1, then no changes are made to state of either the 2168 ** C-API or the SQL function. 2169 ** The second parameter is a pointer to an integer into which 2170 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2171 ** is disabled or enabled following this call. The second parameter may 2172 ** be a NULL pointer, in which case the new setting is not reported back. 2173 ** </dd> 2174 ** 2175 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2176 ** <dd> ^This option is used to change the name of the "main" database 2177 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2178 ** which will become the new schema name in place of "main". ^SQLite 2179 ** does not make a copy of the new main schema name string, so the application 2180 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2181 ** until after the database connection closes. 2182 ** </dd> 2183 ** 2184 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2185 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2186 ** <dd> Usually, when a database in wal mode is closed or detached from a 2187 ** database handle, SQLite checks if this will mean that there are now no 2188 ** connections at all to the database. If so, it performs a checkpoint 2189 ** operation before closing the connection. This option may be used to 2190 ** override this behaviour. The first parameter passed to this operation 2191 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2192 ** default) to enable them, and negative to leave the setting unchanged. 2193 ** The second parameter is a pointer to an integer 2194 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2195 ** have been disabled - 0 if they are not disabled, 1 if they are. 2196 ** </dd> 2197 ** 2198 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2199 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2200 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2201 ** a single SQL query statement will always use the same algorithm regardless 2202 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2203 ** that look at the values of bound parameters, which can make some queries 2204 ** slower. But the QPSG has the advantage of more predictable behavior. With 2205 ** the QPSG active, SQLite will always use the same query plan in the field as 2206 ** was used during testing in the lab. 2207 ** The first argument to this setting is an integer which is 0 to disable 2208 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2209 ** unchanged. The second parameter is a pointer to an integer into which 2210 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2211 ** following this call. 2212 ** </dd> 2213 ** 2214 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2215 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2216 ** include output for any operations performed by trigger programs. This 2217 ** option is used to set or clear (the default) a flag that governs this 2218 ** behavior. The first parameter passed to this operation is an integer - 2219 ** positive to enable output for trigger programs, or zero to disable it, 2220 ** or negative to leave the setting unchanged. 2221 ** The second parameter is a pointer to an integer into which is written 2222 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2223 ** it is not disabled, 1 if it is. 2224 ** </dd> 2225 ** 2226 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2227 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2228 ** [VACUUM] in order to reset a database back to an empty database 2229 ** with no schema and no content. The following process works even for 2230 ** a badly corrupted database file: 2231 ** <ol> 2232 ** <li> If the database connection is newly opened, make sure it has read the 2233 ** database schema by preparing then discarding some query against the 2234 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2235 ** errors. This step is only necessary if the application desires to keep 2236 ** the database in WAL mode after the reset if it was in WAL mode before 2237 ** the reset. 2238 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2239 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2240 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2241 ** </ol> 2242 ** Because resetting a database is destructive and irreversible, the 2243 ** process requires the use of this obscure API and multiple steps to help 2244 ** ensure that it does not happen by accident. 2245 ** 2246 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2247 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2248 ** "defensive" flag for a database connection. When the defensive 2249 ** flag is enabled, language features that allow ordinary SQL to 2250 ** deliberately corrupt the database file are disabled. The disabled 2251 ** features include but are not limited to the following: 2252 ** <ul> 2253 ** <li> The [PRAGMA writable_schema=ON] statement. 2254 ** <li> The [PRAGMA journal_mode=OFF] statement. 2255 ** <li> Writes to the [sqlite_dbpage] virtual table. 2256 ** <li> Direct writes to [shadow tables]. 2257 ** </ul> 2258 ** </dd> 2259 ** 2260 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2261 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2262 ** "writable_schema" flag. This has the same effect and is logically equivalent 2263 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2264 ** The first argument to this setting is an integer which is 0 to disable 2265 ** the writable_schema, positive to enable writable_schema, or negative to 2266 ** leave the setting unchanged. The second parameter is a pointer to an 2267 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2268 ** is enabled or disabled following this call. 2269 ** </dd> 2270 ** 2271 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2272 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2273 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2274 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2275 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2276 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2277 ** additional information. This feature can also be turned on and off 2278 ** using the [PRAGMA legacy_alter_table] statement. 2279 ** </dd> 2280 ** 2281 ** [[SQLITE_DBCONFIG_DQS_DML]] 2282 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2283 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2284 ** the legacy [double-quoted string literal] misfeature for DML statements 2285 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2286 ** default value of this setting is determined by the [-DSQLITE_DQS] 2287 ** compile-time option. 2288 ** </dd> 2289 ** 2290 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2291 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2292 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2293 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2294 ** such as CREATE TABLE and CREATE INDEX. The 2295 ** default value of this setting is determined by the [-DSQLITE_DQS] 2296 ** compile-time option. 2297 ** </dd> 2298 ** 2299 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2300 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2301 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2302 ** assume that database schemas are untainted by malicious content. 2303 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2304 ** takes additional defensive steps to protect the application from harm 2305 ** including: 2306 ** <ul> 2307 ** <li> Prohibit the use of SQL functions inside triggers, views, 2308 ** CHECK constraints, DEFAULT clauses, expression indexes, 2309 ** partial indexes, or generated columns 2310 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2311 ** <li> Prohibit the use of virtual tables inside of triggers or views 2312 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2313 ** </ul> 2314 ** This setting defaults to "on" for legacy compatibility, however 2315 ** all applications are advised to turn it off if possible. This setting 2316 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2317 ** </dd> 2318 ** 2319 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2320 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2321 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2322 ** the legacy file format flag. When activated, this flag causes all newly 2323 ** created database file to have a schema format version number (the 4-byte 2324 ** integer found at offset 44 into the database header) of 1. This in turn 2325 ** means that the resulting database file will be readable and writable by 2326 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2327 ** newly created databases are generally not understandable by SQLite versions 2328 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2329 ** is now scarcely any need to generated database files that are compatible 2330 ** all the way back to version 3.0.0, and so this setting is of little 2331 ** practical use, but is provided so that SQLite can continue to claim the 2332 ** ability to generate new database files that are compatible with version 2333 ** 3.0.0. 2334 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2335 ** the [VACUUM] command will fail with an obscure error when attempting to 2336 ** process a table with generated columns and a descending index. This is 2337 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2338 ** either generated columns or decending indexes. 2339 ** </dd> 2340 ** </dl> 2341 */ 2342 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2343 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2344 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2345 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2346 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2347 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2348 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2349 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2350 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2351 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2352 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2353 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2354 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2355 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2356 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2357 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2358 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2359 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2360 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2361 2362 /* 2363 ** CAPI3REF: Enable Or Disable Extended Result Codes 2364 ** METHOD: sqlite3 2365 ** 2366 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2367 ** [extended result codes] feature of SQLite. ^The extended result 2368 ** codes are disabled by default for historical compatibility. 2369 */ 2370 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2371 2372 /* 2373 ** CAPI3REF: Last Insert Rowid 2374 ** METHOD: sqlite3 2375 ** 2376 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2377 ** has a unique 64-bit signed 2378 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2379 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2380 ** names are not also used by explicitly declared columns. ^If 2381 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2382 ** is another alias for the rowid. 2383 ** 2384 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2385 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2386 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2387 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2388 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2389 ** zero. 2390 ** 2391 ** As well as being set automatically as rows are inserted into database 2392 ** tables, the value returned by this function may be set explicitly by 2393 ** [sqlite3_set_last_insert_rowid()] 2394 ** 2395 ** Some virtual table implementations may INSERT rows into rowid tables as 2396 ** part of committing a transaction (e.g. to flush data accumulated in memory 2397 ** to disk). In this case subsequent calls to this function return the rowid 2398 ** associated with these internal INSERT operations, which leads to 2399 ** unintuitive results. Virtual table implementations that do write to rowid 2400 ** tables in this way can avoid this problem by restoring the original 2401 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2402 ** control to the user. 2403 ** 2404 ** ^(If an [INSERT] occurs within a trigger then this routine will 2405 ** return the [rowid] of the inserted row as long as the trigger is 2406 ** running. Once the trigger program ends, the value returned 2407 ** by this routine reverts to what it was before the trigger was fired.)^ 2408 ** 2409 ** ^An [INSERT] that fails due to a constraint violation is not a 2410 ** successful [INSERT] and does not change the value returned by this 2411 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2412 ** and INSERT OR ABORT make no changes to the return value of this 2413 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2414 ** encounters a constraint violation, it does not fail. The 2415 ** INSERT continues to completion after deleting rows that caused 2416 ** the constraint problem so INSERT OR REPLACE will always change 2417 ** the return value of this interface.)^ 2418 ** 2419 ** ^For the purposes of this routine, an [INSERT] is considered to 2420 ** be successful even if it is subsequently rolled back. 2421 ** 2422 ** This function is accessible to SQL statements via the 2423 ** [last_insert_rowid() SQL function]. 2424 ** 2425 ** If a separate thread performs a new [INSERT] on the same 2426 ** database connection while the [sqlite3_last_insert_rowid()] 2427 ** function is running and thus changes the last insert [rowid], 2428 ** then the value returned by [sqlite3_last_insert_rowid()] is 2429 ** unpredictable and might not equal either the old or the new 2430 ** last insert [rowid]. 2431 */ 2432 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2433 2434 /* 2435 ** CAPI3REF: Set the Last Insert Rowid value. 2436 ** METHOD: sqlite3 2437 ** 2438 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2439 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2440 ** without inserting a row into the database. 2441 */ 2442 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2443 2444 /* 2445 ** CAPI3REF: Count The Number Of Rows Modified 2446 ** METHOD: sqlite3 2447 ** 2448 ** ^This function returns the number of rows modified, inserted or 2449 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2450 ** statement on the database connection specified by the only parameter. 2451 ** ^Executing any other type of SQL statement does not modify the value 2452 ** returned by this function. 2453 ** 2454 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2455 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2456 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2457 ** 2458 ** Changes to a view that are intercepted by 2459 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2460 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2461 ** DELETE statement run on a view is always zero. Only changes made to real 2462 ** tables are counted. 2463 ** 2464 ** Things are more complicated if the sqlite3_changes() function is 2465 ** executed while a trigger program is running. This may happen if the 2466 ** program uses the [changes() SQL function], or if some other callback 2467 ** function invokes sqlite3_changes() directly. Essentially: 2468 ** 2469 ** <ul> 2470 ** <li> ^(Before entering a trigger program the value returned by 2471 ** sqlite3_changes() function is saved. After the trigger program 2472 ** has finished, the original value is restored.)^ 2473 ** 2474 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2475 ** statement sets the value returned by sqlite3_changes() 2476 ** upon completion as normal. Of course, this value will not include 2477 ** any changes performed by sub-triggers, as the sqlite3_changes() 2478 ** value will be saved and restored after each sub-trigger has run.)^ 2479 ** </ul> 2480 ** 2481 ** ^This means that if the changes() SQL function (or similar) is used 2482 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2483 ** returns the value as set when the calling statement began executing. 2484 ** ^If it is used by the second or subsequent such statement within a trigger 2485 ** program, the value returned reflects the number of rows modified by the 2486 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2487 ** 2488 ** If a separate thread makes changes on the same database connection 2489 ** while [sqlite3_changes()] is running then the value returned 2490 ** is unpredictable and not meaningful. 2491 ** 2492 ** See also: 2493 ** <ul> 2494 ** <li> the [sqlite3_total_changes()] interface 2495 ** <li> the [count_changes pragma] 2496 ** <li> the [changes() SQL function] 2497 ** <li> the [data_version pragma] 2498 ** </ul> 2499 */ 2500 SQLITE_API int sqlite3_changes(sqlite3*); 2501 2502 /* 2503 ** CAPI3REF: Total Number Of Rows Modified 2504 ** METHOD: sqlite3 2505 ** 2506 ** ^This function returns the total number of rows inserted, modified or 2507 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2508 ** since the database connection was opened, including those executed as 2509 ** part of trigger programs. ^Executing any other type of SQL statement 2510 ** does not affect the value returned by sqlite3_total_changes(). 2511 ** 2512 ** ^Changes made as part of [foreign key actions] are included in the 2513 ** count, but those made as part of REPLACE constraint resolution are 2514 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2515 ** are not counted. 2516 ** 2517 ** The [sqlite3_total_changes(D)] interface only reports the number 2518 ** of rows that changed due to SQL statement run against database 2519 ** connection D. Any changes by other database connections are ignored. 2520 ** To detect changes against a database file from other database 2521 ** connections use the [PRAGMA data_version] command or the 2522 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2523 ** 2524 ** If a separate thread makes changes on the same database connection 2525 ** while [sqlite3_total_changes()] is running then the value 2526 ** returned is unpredictable and not meaningful. 2527 ** 2528 ** See also: 2529 ** <ul> 2530 ** <li> the [sqlite3_changes()] interface 2531 ** <li> the [count_changes pragma] 2532 ** <li> the [changes() SQL function] 2533 ** <li> the [data_version pragma] 2534 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2535 ** </ul> 2536 */ 2537 SQLITE_API int sqlite3_total_changes(sqlite3*); 2538 2539 /* 2540 ** CAPI3REF: Interrupt A Long-Running Query 2541 ** METHOD: sqlite3 2542 ** 2543 ** ^This function causes any pending database operation to abort and 2544 ** return at its earliest opportunity. This routine is typically 2545 ** called in response to a user action such as pressing "Cancel" 2546 ** or Ctrl-C where the user wants a long query operation to halt 2547 ** immediately. 2548 ** 2549 ** ^It is safe to call this routine from a thread different from the 2550 ** thread that is currently running the database operation. But it 2551 ** is not safe to call this routine with a [database connection] that 2552 ** is closed or might close before sqlite3_interrupt() returns. 2553 ** 2554 ** ^If an SQL operation is very nearly finished at the time when 2555 ** sqlite3_interrupt() is called, then it might not have an opportunity 2556 ** to be interrupted and might continue to completion. 2557 ** 2558 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2559 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2560 ** that is inside an explicit transaction, then the entire transaction 2561 ** will be rolled back automatically. 2562 ** 2563 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2564 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2565 ** that are started after the sqlite3_interrupt() call and before the 2566 ** running statement count reaches zero are interrupted as if they had been 2567 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2568 ** that are started after the running statement count reaches zero are 2569 ** not effected by the sqlite3_interrupt(). 2570 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2571 ** SQL statements is a no-op and has no effect on SQL statements 2572 ** that are started after the sqlite3_interrupt() call returns. 2573 */ 2574 SQLITE_API void sqlite3_interrupt(sqlite3*); 2575 2576 /* 2577 ** CAPI3REF: Determine If An SQL Statement Is Complete 2578 ** 2579 ** These routines are useful during command-line input to determine if the 2580 ** currently entered text seems to form a complete SQL statement or 2581 ** if additional input is needed before sending the text into 2582 ** SQLite for parsing. ^These routines return 1 if the input string 2583 ** appears to be a complete SQL statement. ^A statement is judged to be 2584 ** complete if it ends with a semicolon token and is not a prefix of a 2585 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2586 ** string literals or quoted identifier names or comments are not 2587 ** independent tokens (they are part of the token in which they are 2588 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2589 ** and comments that follow the final semicolon are ignored. 2590 ** 2591 ** ^These routines return 0 if the statement is incomplete. ^If a 2592 ** memory allocation fails, then SQLITE_NOMEM is returned. 2593 ** 2594 ** ^These routines do not parse the SQL statements thus 2595 ** will not detect syntactically incorrect SQL. 2596 ** 2597 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2598 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2599 ** automatically by sqlite3_complete16(). If that initialization fails, 2600 ** then the return value from sqlite3_complete16() will be non-zero 2601 ** regardless of whether or not the input SQL is complete.)^ 2602 ** 2603 ** The input to [sqlite3_complete()] must be a zero-terminated 2604 ** UTF-8 string. 2605 ** 2606 ** The input to [sqlite3_complete16()] must be a zero-terminated 2607 ** UTF-16 string in native byte order. 2608 */ 2609 SQLITE_API int sqlite3_complete(const char *sql); 2610 SQLITE_API int sqlite3_complete16(const void *sql); 2611 2612 /* 2613 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2614 ** KEYWORDS: {busy-handler callback} {busy handler} 2615 ** METHOD: sqlite3 2616 ** 2617 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2618 ** that might be invoked with argument P whenever 2619 ** an attempt is made to access a database table associated with 2620 ** [database connection] D when another thread 2621 ** or process has the table locked. 2622 ** The sqlite3_busy_handler() interface is used to implement 2623 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2624 ** 2625 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2626 ** is returned immediately upon encountering the lock. ^If the busy callback 2627 ** is not NULL, then the callback might be invoked with two arguments. 2628 ** 2629 ** ^The first argument to the busy handler is a copy of the void* pointer which 2630 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2631 ** the busy handler callback is the number of times that the busy handler has 2632 ** been invoked previously for the same locking event. ^If the 2633 ** busy callback returns 0, then no additional attempts are made to 2634 ** access the database and [SQLITE_BUSY] is returned 2635 ** to the application. 2636 ** ^If the callback returns non-zero, then another attempt 2637 ** is made to access the database and the cycle repeats. 2638 ** 2639 ** The presence of a busy handler does not guarantee that it will be invoked 2640 ** when there is lock contention. ^If SQLite determines that invoking the busy 2641 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2642 ** to the application instead of invoking the 2643 ** busy handler. 2644 ** Consider a scenario where one process is holding a read lock that 2645 ** it is trying to promote to a reserved lock and 2646 ** a second process is holding a reserved lock that it is trying 2647 ** to promote to an exclusive lock. The first process cannot proceed 2648 ** because it is blocked by the second and the second process cannot 2649 ** proceed because it is blocked by the first. If both processes 2650 ** invoke the busy handlers, neither will make any progress. Therefore, 2651 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2652 ** will induce the first process to release its read lock and allow 2653 ** the second process to proceed. 2654 ** 2655 ** ^The default busy callback is NULL. 2656 ** 2657 ** ^(There can only be a single busy handler defined for each 2658 ** [database connection]. Setting a new busy handler clears any 2659 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2660 ** or evaluating [PRAGMA busy_timeout=N] will change the 2661 ** busy handler and thus clear any previously set busy handler. 2662 ** 2663 ** The busy callback should not take any actions which modify the 2664 ** database connection that invoked the busy handler. In other words, 2665 ** the busy handler is not reentrant. Any such actions 2666 ** result in undefined behavior. 2667 ** 2668 ** A busy handler must not close the database connection 2669 ** or [prepared statement] that invoked the busy handler. 2670 */ 2671 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2672 2673 /* 2674 ** CAPI3REF: Set A Busy Timeout 2675 ** METHOD: sqlite3 2676 ** 2677 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2678 ** for a specified amount of time when a table is locked. ^The handler 2679 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2680 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2681 ** the handler returns 0 which causes [sqlite3_step()] to return 2682 ** [SQLITE_BUSY]. 2683 ** 2684 ** ^Calling this routine with an argument less than or equal to zero 2685 ** turns off all busy handlers. 2686 ** 2687 ** ^(There can only be a single busy handler for a particular 2688 ** [database connection] at any given moment. If another busy handler 2689 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2690 ** this routine, that other busy handler is cleared.)^ 2691 ** 2692 ** See also: [PRAGMA busy_timeout] 2693 */ 2694 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2695 2696 /* 2697 ** CAPI3REF: Convenience Routines For Running Queries 2698 ** METHOD: sqlite3 2699 ** 2700 ** This is a legacy interface that is preserved for backwards compatibility. 2701 ** Use of this interface is not recommended. 2702 ** 2703 ** Definition: A <b>result table</b> is memory data structure created by the 2704 ** [sqlite3_get_table()] interface. A result table records the 2705 ** complete query results from one or more queries. 2706 ** 2707 ** The table conceptually has a number of rows and columns. But 2708 ** these numbers are not part of the result table itself. These 2709 ** numbers are obtained separately. Let N be the number of rows 2710 ** and M be the number of columns. 2711 ** 2712 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2713 ** There are (N+1)*M elements in the array. The first M pointers point 2714 ** to zero-terminated strings that contain the names of the columns. 2715 ** The remaining entries all point to query results. NULL values result 2716 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2717 ** string representation as returned by [sqlite3_column_text()]. 2718 ** 2719 ** A result table might consist of one or more memory allocations. 2720 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2721 ** A result table should be deallocated using [sqlite3_free_table()]. 2722 ** 2723 ** ^(As an example of the result table format, suppose a query result 2724 ** is as follows: 2725 ** 2726 ** <blockquote><pre> 2727 ** Name | Age 2728 ** ----------------------- 2729 ** Alice | 43 2730 ** Bob | 28 2731 ** Cindy | 21 2732 ** </pre></blockquote> 2733 ** 2734 ** There are two columns (M==2) and three rows (N==3). Thus the 2735 ** result table has 8 entries. Suppose the result table is stored 2736 ** in an array named azResult. Then azResult holds this content: 2737 ** 2738 ** <blockquote><pre> 2739 ** azResult[0] = "Name"; 2740 ** azResult[1] = "Age"; 2741 ** azResult[2] = "Alice"; 2742 ** azResult[3] = "43"; 2743 ** azResult[4] = "Bob"; 2744 ** azResult[5] = "28"; 2745 ** azResult[6] = "Cindy"; 2746 ** azResult[7] = "21"; 2747 ** </pre></blockquote>)^ 2748 ** 2749 ** ^The sqlite3_get_table() function evaluates one or more 2750 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2751 ** string of its 2nd parameter and returns a result table to the 2752 ** pointer given in its 3rd parameter. 2753 ** 2754 ** After the application has finished with the result from sqlite3_get_table(), 2755 ** it must pass the result table pointer to sqlite3_free_table() in order to 2756 ** release the memory that was malloced. Because of the way the 2757 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2758 ** function must not try to call [sqlite3_free()] directly. Only 2759 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2760 ** 2761 ** The sqlite3_get_table() interface is implemented as a wrapper around 2762 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2763 ** to any internal data structures of SQLite. It uses only the public 2764 ** interface defined here. As a consequence, errors that occur in the 2765 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2766 ** reflected in subsequent calls to [sqlite3_errcode()] or 2767 ** [sqlite3_errmsg()]. 2768 */ 2769 SQLITE_API int sqlite3_get_table( 2770 sqlite3 *db, /* An open database */ 2771 const char *zSql, /* SQL to be evaluated */ 2772 char ***pazResult, /* Results of the query */ 2773 int *pnRow, /* Number of result rows written here */ 2774 int *pnColumn, /* Number of result columns written here */ 2775 char **pzErrmsg /* Error msg written here */ 2776 ); 2777 SQLITE_API void sqlite3_free_table(char **result); 2778 2779 /* 2780 ** CAPI3REF: Formatted String Printing Functions 2781 ** 2782 ** These routines are work-alikes of the "printf()" family of functions 2783 ** from the standard C library. 2784 ** These routines understand most of the common formatting options from 2785 ** the standard library printf() 2786 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2787 ** See the [built-in printf()] documentation for details. 2788 ** 2789 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2790 ** results into memory obtained from [sqlite3_malloc64()]. 2791 ** The strings returned by these two routines should be 2792 ** released by [sqlite3_free()]. ^Both routines return a 2793 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2794 ** memory to hold the resulting string. 2795 ** 2796 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2797 ** the standard C library. The result is written into the 2798 ** buffer supplied as the second parameter whose size is given by 2799 ** the first parameter. Note that the order of the 2800 ** first two parameters is reversed from snprintf().)^ This is an 2801 ** historical accident that cannot be fixed without breaking 2802 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2803 ** returns a pointer to its buffer instead of the number of 2804 ** characters actually written into the buffer.)^ We admit that 2805 ** the number of characters written would be a more useful return 2806 ** value but we cannot change the implementation of sqlite3_snprintf() 2807 ** now without breaking compatibility. 2808 ** 2809 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2810 ** guarantees that the buffer is always zero-terminated. ^The first 2811 ** parameter "n" is the total size of the buffer, including space for 2812 ** the zero terminator. So the longest string that can be completely 2813 ** written will be n-1 characters. 2814 ** 2815 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2816 ** 2817 ** See also: [built-in printf()], [printf() SQL function] 2818 */ 2819 SQLITE_API char *sqlite3_mprintf(const char*,...); 2820 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2821 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2822 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2823 2824 /* 2825 ** CAPI3REF: Memory Allocation Subsystem 2826 ** 2827 ** The SQLite core uses these three routines for all of its own 2828 ** internal memory allocation needs. "Core" in the previous sentence 2829 ** does not include operating-system specific [VFS] implementation. The 2830 ** Windows VFS uses native malloc() and free() for some operations. 2831 ** 2832 ** ^The sqlite3_malloc() routine returns a pointer to a block 2833 ** of memory at least N bytes in length, where N is the parameter. 2834 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2835 ** memory, it returns a NULL pointer. ^If the parameter N to 2836 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2837 ** a NULL pointer. 2838 ** 2839 ** ^The sqlite3_malloc64(N) routine works just like 2840 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2841 ** of a signed 32-bit integer. 2842 ** 2843 ** ^Calling sqlite3_free() with a pointer previously returned 2844 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2845 ** that it might be reused. ^The sqlite3_free() routine is 2846 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2847 ** to sqlite3_free() is harmless. After being freed, memory 2848 ** should neither be read nor written. Even reading previously freed 2849 ** memory might result in a segmentation fault or other severe error. 2850 ** Memory corruption, a segmentation fault, or other severe error 2851 ** might result if sqlite3_free() is called with a non-NULL pointer that 2852 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2853 ** 2854 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2855 ** prior memory allocation X to be at least N bytes. 2856 ** ^If the X parameter to sqlite3_realloc(X,N) 2857 ** is a NULL pointer then its behavior is identical to calling 2858 ** sqlite3_malloc(N). 2859 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2860 ** negative then the behavior is exactly the same as calling 2861 ** sqlite3_free(X). 2862 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2863 ** of at least N bytes in size or NULL if insufficient memory is available. 2864 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2865 ** of the prior allocation are copied into the beginning of buffer returned 2866 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2867 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2868 ** prior allocation is not freed. 2869 ** 2870 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2871 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2872 ** of a 32-bit signed integer. 2873 ** 2874 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2875 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2876 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2877 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2878 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2879 ** sqlite3_msize(X) returns zero. If X points to something that is not 2880 ** the beginning of memory allocation, or if it points to a formerly 2881 ** valid memory allocation that has now been freed, then the behavior 2882 ** of sqlite3_msize(X) is undefined and possibly harmful. 2883 ** 2884 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2885 ** sqlite3_malloc64(), and sqlite3_realloc64() 2886 ** is always aligned to at least an 8 byte boundary, or to a 2887 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2888 ** option is used. 2889 ** 2890 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2891 ** must be either NULL or else pointers obtained from a prior 2892 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2893 ** not yet been released. 2894 ** 2895 ** The application must not read or write any part of 2896 ** a block of memory after it has been released using 2897 ** [sqlite3_free()] or [sqlite3_realloc()]. 2898 */ 2899 SQLITE_API void *sqlite3_malloc(int); 2900 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2901 SQLITE_API void *sqlite3_realloc(void*, int); 2902 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2903 SQLITE_API void sqlite3_free(void*); 2904 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2905 2906 /* 2907 ** CAPI3REF: Memory Allocator Statistics 2908 ** 2909 ** SQLite provides these two interfaces for reporting on the status 2910 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2911 ** routines, which form the built-in memory allocation subsystem. 2912 ** 2913 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2914 ** of memory currently outstanding (malloced but not freed). 2915 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2916 ** value of [sqlite3_memory_used()] since the high-water mark 2917 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2918 ** [sqlite3_memory_highwater()] include any overhead 2919 ** added by SQLite in its implementation of [sqlite3_malloc()], 2920 ** but not overhead added by the any underlying system library 2921 ** routines that [sqlite3_malloc()] may call. 2922 ** 2923 ** ^The memory high-water mark is reset to the current value of 2924 ** [sqlite3_memory_used()] if and only if the parameter to 2925 ** [sqlite3_memory_highwater()] is true. ^The value returned 2926 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2927 ** prior to the reset. 2928 */ 2929 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2930 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2931 2932 /* 2933 ** CAPI3REF: Pseudo-Random Number Generator 2934 ** 2935 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2936 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2937 ** already uses the largest possible [ROWID]. The PRNG is also used for 2938 ** the built-in random() and randomblob() SQL functions. This interface allows 2939 ** applications to access the same PRNG for other purposes. 2940 ** 2941 ** ^A call to this routine stores N bytes of randomness into buffer P. 2942 ** ^The P parameter can be a NULL pointer. 2943 ** 2944 ** ^If this routine has not been previously called or if the previous 2945 ** call had N less than one or a NULL pointer for P, then the PRNG is 2946 ** seeded using randomness obtained from the xRandomness method of 2947 ** the default [sqlite3_vfs] object. 2948 ** ^If the previous call to this routine had an N of 1 or more and a 2949 ** non-NULL P then the pseudo-randomness is generated 2950 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2951 ** method. 2952 */ 2953 SQLITE_API void sqlite3_randomness(int N, void *P); 2954 2955 /* 2956 ** CAPI3REF: Compile-Time Authorization Callbacks 2957 ** METHOD: sqlite3 2958 ** KEYWORDS: {authorizer callback} 2959 ** 2960 ** ^This routine registers an authorizer callback with a particular 2961 ** [database connection], supplied in the first argument. 2962 ** ^The authorizer callback is invoked as SQL statements are being compiled 2963 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2964 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2965 ** and [sqlite3_prepare16_v3()]. ^At various 2966 ** points during the compilation process, as logic is being created 2967 ** to perform various actions, the authorizer callback is invoked to 2968 ** see if those actions are allowed. ^The authorizer callback should 2969 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2970 ** specific action but allow the SQL statement to continue to be 2971 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2972 ** rejected with an error. ^If the authorizer callback returns 2973 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2974 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2975 ** the authorizer will fail with an error message. 2976 ** 2977 ** When the callback returns [SQLITE_OK], that means the operation 2978 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2979 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2980 ** authorizer will fail with an error message explaining that 2981 ** access is denied. 2982 ** 2983 ** ^The first parameter to the authorizer callback is a copy of the third 2984 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2985 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2986 ** the particular action to be authorized. ^The third through sixth parameters 2987 ** to the callback are either NULL pointers or zero-terminated strings 2988 ** that contain additional details about the action to be authorized. 2989 ** Applications must always be prepared to encounter a NULL pointer in any 2990 ** of the third through the sixth parameters of the authorization callback. 2991 ** 2992 ** ^If the action code is [SQLITE_READ] 2993 ** and the callback returns [SQLITE_IGNORE] then the 2994 ** [prepared statement] statement is constructed to substitute 2995 ** a NULL value in place of the table column that would have 2996 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2997 ** return can be used to deny an untrusted user access to individual 2998 ** columns of a table. 2999 ** ^When a table is referenced by a [SELECT] but no column values are 3000 ** extracted from that table (for example in a query like 3001 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3002 ** is invoked once for that table with a column name that is an empty string. 3003 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3004 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3005 ** [truncate optimization] is disabled and all rows are deleted individually. 3006 ** 3007 ** An authorizer is used when [sqlite3_prepare | preparing] 3008 ** SQL statements from an untrusted source, to ensure that the SQL statements 3009 ** do not try to access data they are not allowed to see, or that they do not 3010 ** try to execute malicious statements that damage the database. For 3011 ** example, an application may allow a user to enter arbitrary 3012 ** SQL queries for evaluation by a database. But the application does 3013 ** not want the user to be able to make arbitrary changes to the 3014 ** database. An authorizer could then be put in place while the 3015 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3016 ** disallows everything except [SELECT] statements. 3017 ** 3018 ** Applications that need to process SQL from untrusted sources 3019 ** might also consider lowering resource limits using [sqlite3_limit()] 3020 ** and limiting database size using the [max_page_count] [PRAGMA] 3021 ** in addition to using an authorizer. 3022 ** 3023 ** ^(Only a single authorizer can be in place on a database connection 3024 ** at a time. Each call to sqlite3_set_authorizer overrides the 3025 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3026 ** The authorizer is disabled by default. 3027 ** 3028 ** The authorizer callback must not do anything that will modify 3029 ** the database connection that invoked the authorizer callback. 3030 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3031 ** database connections for the meaning of "modify" in this paragraph. 3032 ** 3033 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3034 ** statement might be re-prepared during [sqlite3_step()] due to a 3035 ** schema change. Hence, the application should ensure that the 3036 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3037 ** 3038 ** ^Note that the authorizer callback is invoked only during 3039 ** [sqlite3_prepare()] or its variants. Authorization is not 3040 ** performed during statement evaluation in [sqlite3_step()], unless 3041 ** as stated in the previous paragraph, sqlite3_step() invokes 3042 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3043 */ 3044 SQLITE_API int sqlite3_set_authorizer( 3045 sqlite3*, 3046 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3047 void *pUserData 3048 ); 3049 3050 /* 3051 ** CAPI3REF: Authorizer Return Codes 3052 ** 3053 ** The [sqlite3_set_authorizer | authorizer callback function] must 3054 ** return either [SQLITE_OK] or one of these two constants in order 3055 ** to signal SQLite whether or not the action is permitted. See the 3056 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3057 ** information. 3058 ** 3059 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3060 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3061 */ 3062 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3063 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3064 3065 /* 3066 ** CAPI3REF: Authorizer Action Codes 3067 ** 3068 ** The [sqlite3_set_authorizer()] interface registers a callback function 3069 ** that is invoked to authorize certain SQL statement actions. The 3070 ** second parameter to the callback is an integer code that specifies 3071 ** what action is being authorized. These are the integer action codes that 3072 ** the authorizer callback may be passed. 3073 ** 3074 ** These action code values signify what kind of operation is to be 3075 ** authorized. The 3rd and 4th parameters to the authorization 3076 ** callback function will be parameters or NULL depending on which of these 3077 ** codes is used as the second parameter. ^(The 5th parameter to the 3078 ** authorizer callback is the name of the database ("main", "temp", 3079 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3080 ** is the name of the inner-most trigger or view that is responsible for 3081 ** the access attempt or NULL if this access attempt is directly from 3082 ** top-level SQL code. 3083 */ 3084 /******************************************* 3rd ************ 4th ***********/ 3085 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3086 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3087 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3088 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3089 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3090 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3091 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3092 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3093 #define SQLITE_DELETE 9 /* Table Name NULL */ 3094 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3095 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3096 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3097 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3098 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3099 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3100 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3101 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3102 #define SQLITE_INSERT 18 /* Table Name NULL */ 3103 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3104 #define SQLITE_READ 20 /* Table Name Column Name */ 3105 #define SQLITE_SELECT 21 /* NULL NULL */ 3106 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3107 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3108 #define SQLITE_ATTACH 24 /* Filename NULL */ 3109 #define SQLITE_DETACH 25 /* Database Name NULL */ 3110 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3111 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3112 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3113 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3114 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3115 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3116 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3117 #define SQLITE_COPY 0 /* No longer used */ 3118 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3119 3120 /* 3121 ** CAPI3REF: Tracing And Profiling Functions 3122 ** METHOD: sqlite3 3123 ** 3124 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3125 ** instead of the routines described here. 3126 ** 3127 ** These routines register callback functions that can be used for 3128 ** tracing and profiling the execution of SQL statements. 3129 ** 3130 ** ^The callback function registered by sqlite3_trace() is invoked at 3131 ** various times when an SQL statement is being run by [sqlite3_step()]. 3132 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3133 ** SQL statement text as the statement first begins executing. 3134 ** ^(Additional sqlite3_trace() callbacks might occur 3135 ** as each triggered subprogram is entered. The callbacks for triggers 3136 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3137 ** 3138 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3139 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3140 ** 3141 ** ^The callback function registered by sqlite3_profile() is invoked 3142 ** as each SQL statement finishes. ^The profile callback contains 3143 ** the original statement text and an estimate of wall-clock time 3144 ** of how long that statement took to run. ^The profile callback 3145 ** time is in units of nanoseconds, however the current implementation 3146 ** is only capable of millisecond resolution so the six least significant 3147 ** digits in the time are meaningless. Future versions of SQLite 3148 ** might provide greater resolution on the profiler callback. Invoking 3149 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3150 ** profile callback. 3151 */ 3152 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3153 void(*xTrace)(void*,const char*), void*); 3154 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3155 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3156 3157 /* 3158 ** CAPI3REF: SQL Trace Event Codes 3159 ** KEYWORDS: SQLITE_TRACE 3160 ** 3161 ** These constants identify classes of events that can be monitored 3162 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3163 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3164 ** the following constants. ^The first argument to the trace callback 3165 ** is one of the following constants. 3166 ** 3167 ** New tracing constants may be added in future releases. 3168 ** 3169 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3170 ** ^The T argument is one of the integer type codes above. 3171 ** ^The C argument is a copy of the context pointer passed in as the 3172 ** fourth argument to [sqlite3_trace_v2()]. 3173 ** The P and X arguments are pointers whose meanings depend on T. 3174 ** 3175 ** <dl> 3176 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3177 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3178 ** first begins running and possibly at other times during the 3179 ** execution of the prepared statement, such as at the start of each 3180 ** trigger subprogram. ^The P argument is a pointer to the 3181 ** [prepared statement]. ^The X argument is a pointer to a string which 3182 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3183 ** that indicates the invocation of a trigger. ^The callback can compute 3184 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3185 ** interface by using the X argument when X begins with "--" and invoking 3186 ** [sqlite3_expanded_sql(P)] otherwise. 3187 ** 3188 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3189 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3190 ** information as is provided by the [sqlite3_profile()] callback. 3191 ** ^The P argument is a pointer to the [prepared statement] and the 3192 ** X argument points to a 64-bit integer which is the estimated of 3193 ** the number of nanosecond that the prepared statement took to run. 3194 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3195 ** 3196 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3197 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3198 ** statement generates a single row of result. 3199 ** ^The P argument is a pointer to the [prepared statement] and the 3200 ** X argument is unused. 3201 ** 3202 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3203 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3204 ** connection closes. 3205 ** ^The P argument is a pointer to the [database connection] object 3206 ** and the X argument is unused. 3207 ** </dl> 3208 */ 3209 #define SQLITE_TRACE_STMT 0x01 3210 #define SQLITE_TRACE_PROFILE 0x02 3211 #define SQLITE_TRACE_ROW 0x04 3212 #define SQLITE_TRACE_CLOSE 0x08 3213 3214 /* 3215 ** CAPI3REF: SQL Trace Hook 3216 ** METHOD: sqlite3 3217 ** 3218 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3219 ** function X against [database connection] D, using property mask M 3220 ** and context pointer P. ^If the X callback is 3221 ** NULL or if the M mask is zero, then tracing is disabled. The 3222 ** M argument should be the bitwise OR-ed combination of 3223 ** zero or more [SQLITE_TRACE] constants. 3224 ** 3225 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3226 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3227 ** 3228 ** ^The X callback is invoked whenever any of the events identified by 3229 ** mask M occur. ^The integer return value from the callback is currently 3230 ** ignored, though this may change in future releases. Callback 3231 ** implementations should return zero to ensure future compatibility. 3232 ** 3233 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3234 ** ^The T argument is one of the [SQLITE_TRACE] 3235 ** constants to indicate why the callback was invoked. 3236 ** ^The C argument is a copy of the context pointer. 3237 ** The P and X arguments are pointers whose meanings depend on T. 3238 ** 3239 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3240 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3241 ** are deprecated. 3242 */ 3243 SQLITE_API int sqlite3_trace_v2( 3244 sqlite3*, 3245 unsigned uMask, 3246 int(*xCallback)(unsigned,void*,void*,void*), 3247 void *pCtx 3248 ); 3249 3250 /* 3251 ** CAPI3REF: Query Progress Callbacks 3252 ** METHOD: sqlite3 3253 ** 3254 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3255 ** function X to be invoked periodically during long running calls to 3256 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3257 ** database connection D. An example use for this 3258 ** interface is to keep a GUI updated during a large query. 3259 ** 3260 ** ^The parameter P is passed through as the only parameter to the 3261 ** callback function X. ^The parameter N is the approximate number of 3262 ** [virtual machine instructions] that are evaluated between successive 3263 ** invocations of the callback X. ^If N is less than one then the progress 3264 ** handler is disabled. 3265 ** 3266 ** ^Only a single progress handler may be defined at one time per 3267 ** [database connection]; setting a new progress handler cancels the 3268 ** old one. ^Setting parameter X to NULL disables the progress handler. 3269 ** ^The progress handler is also disabled by setting N to a value less 3270 ** than 1. 3271 ** 3272 ** ^If the progress callback returns non-zero, the operation is 3273 ** interrupted. This feature can be used to implement a 3274 ** "Cancel" button on a GUI progress dialog box. 3275 ** 3276 ** The progress handler callback must not do anything that will modify 3277 ** the database connection that invoked the progress handler. 3278 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3279 ** database connections for the meaning of "modify" in this paragraph. 3280 ** 3281 */ 3282 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3283 3284 /* 3285 ** CAPI3REF: Opening A New Database Connection 3286 ** CONSTRUCTOR: sqlite3 3287 ** 3288 ** ^These routines open an SQLite database file as specified by the 3289 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3290 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3291 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3292 ** returned in *ppDb, even if an error occurs. The only exception is that 3293 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3294 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3295 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3296 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3297 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3298 ** an English language description of the error following a failure of any 3299 ** of the sqlite3_open() routines. 3300 ** 3301 ** ^The default encoding will be UTF-8 for databases created using 3302 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3303 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3304 ** 3305 ** Whether or not an error occurs when it is opened, resources 3306 ** associated with the [database connection] handle should be released by 3307 ** passing it to [sqlite3_close()] when it is no longer required. 3308 ** 3309 ** The sqlite3_open_v2() interface works like sqlite3_open() 3310 ** except that it accepts two additional parameters for additional control 3311 ** over the new database connection. ^(The flags parameter to 3312 ** sqlite3_open_v2() must include, at a minimum, one of the following 3313 ** three flag combinations:)^ 3314 ** 3315 ** <dl> 3316 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3317 ** <dd>The database is opened in read-only mode. If the database does not 3318 ** already exist, an error is returned.</dd>)^ 3319 ** 3320 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3321 ** <dd>The database is opened for reading and writing if possible, or reading 3322 ** only if the file is write protected by the operating system. In either 3323 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3324 ** 3325 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3326 ** <dd>The database is opened for reading and writing, and is created if 3327 ** it does not already exist. This is the behavior that is always used for 3328 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3329 ** </dl> 3330 ** 3331 ** In addition to the required flags, the following optional flags are 3332 ** also supported: 3333 ** 3334 ** <dl> 3335 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3336 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3337 ** 3338 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3339 ** <dd>The database will be opened as an in-memory database. The database 3340 ** is named by the "filename" argument for the purposes of cache-sharing, 3341 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3342 ** </dd>)^ 3343 ** 3344 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3345 ** <dd>The new database connection will use the "multi-thread" 3346 ** [threading mode].)^ This means that separate threads are allowed 3347 ** to use SQLite at the same time, as long as each thread is using 3348 ** a different [database connection]. 3349 ** 3350 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3351 ** <dd>The new database connection will use the "serialized" 3352 ** [threading mode].)^ This means the multiple threads can safely 3353 ** attempt to use the same database connection at the same time. 3354 ** (Mutexes will block any actual concurrency, but in this mode 3355 ** there is no harm in trying.) 3356 ** 3357 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3358 ** <dd>The database is opened [shared cache] enabled, overriding 3359 ** the default shared cache setting provided by 3360 ** [sqlite3_enable_shared_cache()].)^ 3361 ** 3362 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3363 ** <dd>The database is opened [shared cache] disabled, overriding 3364 ** the default shared cache setting provided by 3365 ** [sqlite3_enable_shared_cache()].)^ 3366 ** 3367 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3368 ** <dd>The database filename is not allowed to be a symbolic link</dd> 3369 ** </dl>)^ 3370 ** 3371 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3372 ** required combinations shown above optionally combined with other 3373 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3374 ** then the behavior is undefined. 3375 ** 3376 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3377 ** [sqlite3_vfs] object that defines the operating system interface that 3378 ** the new database connection should use. ^If the fourth parameter is 3379 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3380 ** 3381 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3382 ** is created for the connection. ^This in-memory database will vanish when 3383 ** the database connection is closed. Future versions of SQLite might 3384 ** make use of additional special filenames that begin with the ":" character. 3385 ** It is recommended that when a database filename actually does begin with 3386 ** a ":" character you should prefix the filename with a pathname such as 3387 ** "./" to avoid ambiguity. 3388 ** 3389 ** ^If the filename is an empty string, then a private, temporary 3390 ** on-disk database will be created. ^This private database will be 3391 ** automatically deleted as soon as the database connection is closed. 3392 ** 3393 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3394 ** 3395 ** ^If [URI filename] interpretation is enabled, and the filename argument 3396 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3397 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3398 ** set in the third argument to sqlite3_open_v2(), or if it has 3399 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3400 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3401 ** URI filename interpretation is turned off 3402 ** by default, but future releases of SQLite might enable URI filename 3403 ** interpretation by default. See "[URI filenames]" for additional 3404 ** information. 3405 ** 3406 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3407 ** authority, then it must be either an empty string or the string 3408 ** "localhost". ^If the authority is not an empty string or "localhost", an 3409 ** error is returned to the caller. ^The fragment component of a URI, if 3410 ** present, is ignored. 3411 ** 3412 ** ^SQLite uses the path component of the URI as the name of the disk file 3413 ** which contains the database. ^If the path begins with a '/' character, 3414 ** then it is interpreted as an absolute path. ^If the path does not begin 3415 ** with a '/' (meaning that the authority section is omitted from the URI) 3416 ** then the path is interpreted as a relative path. 3417 ** ^(On windows, the first component of an absolute path 3418 ** is a drive specification (e.g. "C:").)^ 3419 ** 3420 ** [[core URI query parameters]] 3421 ** The query component of a URI may contain parameters that are interpreted 3422 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3423 ** SQLite and its built-in [VFSes] interpret the 3424 ** following query parameters: 3425 ** 3426 ** <ul> 3427 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3428 ** a VFS object that provides the operating system interface that should 3429 ** be used to access the database file on disk. ^If this option is set to 3430 ** an empty string the default VFS object is used. ^Specifying an unknown 3431 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3432 ** present, then the VFS specified by the option takes precedence over 3433 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3434 ** 3435 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3436 ** "rwc", or "memory". Attempting to set it to any other value is 3437 ** an error)^. 3438 ** ^If "ro" is specified, then the database is opened for read-only 3439 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3440 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3441 ** "rw", then the database is opened for read-write (but not create) 3442 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3443 ** been set. ^Value "rwc" is equivalent to setting both 3444 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3445 ** set to "memory" then a pure [in-memory database] that never reads 3446 ** or writes from disk is used. ^It is an error to specify a value for 3447 ** the mode parameter that is less restrictive than that specified by 3448 ** the flags passed in the third parameter to sqlite3_open_v2(). 3449 ** 3450 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3451 ** "private". ^Setting it to "shared" is equivalent to setting the 3452 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3453 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3454 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3455 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3456 ** a URI filename, its value overrides any behavior requested by setting 3457 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3458 ** 3459 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3460 ** [powersafe overwrite] property does or does not apply to the 3461 ** storage media on which the database file resides. 3462 ** 3463 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3464 ** which if set disables file locking in rollback journal modes. This 3465 ** is useful for accessing a database on a filesystem that does not 3466 ** support locking. Caution: Database corruption might result if two 3467 ** or more processes write to the same database and any one of those 3468 ** processes uses nolock=1. 3469 ** 3470 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3471 ** parameter that indicates that the database file is stored on 3472 ** read-only media. ^When immutable is set, SQLite assumes that the 3473 ** database file cannot be changed, even by a process with higher 3474 ** privilege, and so the database is opened read-only and all locking 3475 ** and change detection is disabled. Caution: Setting the immutable 3476 ** property on a database file that does in fact change can result 3477 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3478 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3479 ** 3480 ** </ul> 3481 ** 3482 ** ^Specifying an unknown parameter in the query component of a URI is not an 3483 ** error. Future versions of SQLite might understand additional query 3484 ** parameters. See "[query parameters with special meaning to SQLite]" for 3485 ** additional information. 3486 ** 3487 ** [[URI filename examples]] <h3>URI filename examples</h3> 3488 ** 3489 ** <table border="1" align=center cellpadding=5> 3490 ** <tr><th> URI filenames <th> Results 3491 ** <tr><td> file:data.db <td> 3492 ** Open the file "data.db" in the current directory. 3493 ** <tr><td> file:/home/fred/data.db<br> 3494 ** file:///home/fred/data.db <br> 3495 ** file://localhost/home/fred/data.db <br> <td> 3496 ** Open the database file "/home/fred/data.db". 3497 ** <tr><td> file://darkstar/home/fred/data.db <td> 3498 ** An error. "darkstar" is not a recognized authority. 3499 ** <tr><td style="white-space:nowrap"> 3500 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3501 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3502 ** C:. Note that the %20 escaping in this example is not strictly 3503 ** necessary - space characters can be used literally 3504 ** in URI filenames. 3505 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3506 ** Open file "data.db" in the current directory for read-only access. 3507 ** Regardless of whether or not shared-cache mode is enabled by 3508 ** default, use a private cache. 3509 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3510 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3511 ** that uses dot-files in place of posix advisory locking. 3512 ** <tr><td> file:data.db?mode=readonly <td> 3513 ** An error. "readonly" is not a valid option for the "mode" parameter. 3514 ** Use "ro" instead: "file:data.db?mode=ro". 3515 ** </table> 3516 ** 3517 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3518 ** query components of a URI. A hexadecimal escape sequence consists of a 3519 ** percent sign - "%" - followed by exactly two hexadecimal digits 3520 ** specifying an octet value. ^Before the path or query components of a 3521 ** URI filename are interpreted, they are encoded using UTF-8 and all 3522 ** hexadecimal escape sequences replaced by a single byte containing the 3523 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3524 ** the results are undefined. 3525 ** 3526 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3527 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3528 ** codepage is currently defined. Filenames containing international 3529 ** characters must be converted to UTF-8 prior to passing them into 3530 ** sqlite3_open() or sqlite3_open_v2(). 3531 ** 3532 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3533 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3534 ** features that require the use of temporary files may fail. 3535 ** 3536 ** See also: [sqlite3_temp_directory] 3537 */ 3538 SQLITE_API int sqlite3_open( 3539 const char *filename, /* Database filename (UTF-8) */ 3540 sqlite3 **ppDb /* OUT: SQLite db handle */ 3541 ); 3542 SQLITE_API int sqlite3_open16( 3543 const void *filename, /* Database filename (UTF-16) */ 3544 sqlite3 **ppDb /* OUT: SQLite db handle */ 3545 ); 3546 SQLITE_API int sqlite3_open_v2( 3547 const char *filename, /* Database filename (UTF-8) */ 3548 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3549 int flags, /* Flags */ 3550 const char *zVfs /* Name of VFS module to use */ 3551 ); 3552 3553 /* 3554 ** CAPI3REF: Obtain Values For URI Parameters 3555 ** 3556 ** These are utility routines, useful to [VFS|custom VFS implementations], 3557 ** that check if a database file was a URI that contained a specific query 3558 ** parameter, and if so obtains the value of that query parameter. 3559 ** 3560 ** The first parameter to these interfaces (hereafter referred to 3561 ** as F) must be one of: 3562 ** <ul> 3563 ** <li> A database filename pointer created by the SQLite core and 3564 ** passed into the xOpen() method of a VFS implemention, or 3565 ** <li> A filename obtained from [sqlite3_db_filename()], or 3566 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3567 ** </ul> 3568 ** If the F parameter is not one of the above, then the behavior is 3569 ** undefined and probably undesirable. Older versions of SQLite were 3570 ** more tolerant of invalid F parameters than newer versions. 3571 ** 3572 ** If F is a suitable filename (as described in the previous paragraph) 3573 ** and if P is the name of the query parameter, then 3574 ** sqlite3_uri_parameter(F,P) returns the value of the P 3575 ** parameter if it exists or a NULL pointer if P does not appear as a 3576 ** query parameter on F. If P is a query parameter of F and it 3577 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3578 ** a pointer to an empty string. 3579 ** 3580 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3581 ** parameter and returns true (1) or false (0) according to the value 3582 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3583 ** value of query parameter P is one of "yes", "true", or "on" in any 3584 ** case or if the value begins with a non-zero number. The 3585 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3586 ** query parameter P is one of "no", "false", or "off" in any case or 3587 ** if the value begins with a numeric zero. If P is not a query 3588 ** parameter on F or if the value of P does not match any of the 3589 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3590 ** 3591 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3592 ** 64-bit signed integer and returns that integer, or D if P does not 3593 ** exist. If the value of P is something other than an integer, then 3594 ** zero is returned. 3595 ** 3596 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3597 ** the value) of the N-th query parameter for filename F, or a NULL 3598 ** pointer if N is less than zero or greater than the number of query 3599 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3600 ** the name of the first query parameter, 1 for the second parameter, and 3601 ** so forth. 3602 ** 3603 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3604 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3605 ** is not a database file pathname pointer that the SQLite core passed 3606 ** into the xOpen VFS method, then the behavior of this routine is undefined 3607 ** and probably undesirable. 3608 ** 3609 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3610 ** parameter can also be the name of a rollback journal file or WAL file 3611 ** in addition to the main database file. Prior to version 3.31.0, these 3612 ** routines would only work if F was the name of the main database file. 3613 ** When the F parameter is the name of the rollback journal or WAL file, 3614 ** it has access to all the same query parameters as were found on the 3615 ** main database file. 3616 ** 3617 ** See the [URI filename] documentation for additional information. 3618 */ 3619 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3620 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3621 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3622 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3623 3624 /* 3625 ** CAPI3REF: Translate filenames 3626 ** 3627 ** These routines are available to [VFS|custom VFS implementations] for 3628 ** translating filenames between the main database file, the journal file, 3629 ** and the WAL file. 3630 ** 3631 ** If F is the name of an sqlite database file, journal file, or WAL file 3632 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3633 ** returns the name of the corresponding database file. 3634 ** 3635 ** If F is the name of an sqlite database file, journal file, or WAL file 3636 ** passed by the SQLite core into the VFS, or if F is a database filename 3637 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3638 ** returns the name of the corresponding rollback journal file. 3639 ** 3640 ** If F is the name of an sqlite database file, journal file, or WAL file 3641 ** that was passed by the SQLite core into the VFS, or if F is a database 3642 ** filename obtained from [sqlite3_db_filename()], then 3643 ** sqlite3_filename_wal(F) returns the name of the corresponding 3644 ** WAL file. 3645 ** 3646 ** In all of the above, if F is not the name of a database, journal or WAL 3647 ** filename passed into the VFS from the SQLite core and F is not the 3648 ** return value from [sqlite3_db_filename()], then the result is 3649 ** undefined and is likely a memory access violation. 3650 */ 3651 SQLITE_API const char *sqlite3_filename_database(const char*); 3652 SQLITE_API const char *sqlite3_filename_journal(const char*); 3653 SQLITE_API const char *sqlite3_filename_wal(const char*); 3654 3655 /* 3656 ** CAPI3REF: Database File Corresponding To A Journal 3657 ** 3658 ** ^If X is the name of a rollback or WAL-mode journal file that is 3659 ** passed into the xOpen method of [sqlite3_vfs], then 3660 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3661 ** object that represents the main database file. 3662 ** 3663 ** This routine is intended for use in custom [VFS] implementations 3664 ** only. It is not a general-purpose interface. 3665 ** The argument sqlite3_file_object(X) must be a filename pointer that 3666 ** has been passed into [sqlite3_vfs].xOpen method where the 3667 ** flags parameter to xOpen contains one of the bits 3668 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3669 ** of this routine results in undefined and probably undesirable 3670 ** behavior. 3671 */ 3672 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3673 3674 /* 3675 ** CAPI3REF: Create and Destroy VFS Filenames 3676 ** 3677 ** These interfces are provided for use by [VFS shim] implementations and 3678 ** are not useful outside of that context. 3679 ** 3680 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3681 ** database filename D with corresponding journal file J and WAL file W and 3682 ** with N URI parameters key/values pairs in the array P. The result from 3683 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3684 ** is safe to pass to routines like: 3685 ** <ul> 3686 ** <li> [sqlite3_uri_parameter()], 3687 ** <li> [sqlite3_uri_boolean()], 3688 ** <li> [sqlite3_uri_int64()], 3689 ** <li> [sqlite3_uri_key()], 3690 ** <li> [sqlite3_filename_database()], 3691 ** <li> [sqlite3_filename_journal()], or 3692 ** <li> [sqlite3_filename_wal()]. 3693 ** </ul> 3694 ** If a memory allocation error occurs, sqlite3_create_filename() might 3695 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3696 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3697 ** 3698 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3699 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3700 ** to a key and value for a query parameter. The P parameter may be a NULL 3701 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3702 ** NULL pointers and key pointers should not be empty strings. 3703 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3704 ** be NULL pointers, though they can be empty strings. 3705 ** 3706 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3707 ** previously obtained from sqlite3_create_filename(). Invoking 3708 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3709 ** 3710 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3711 ** than a NULL pointer or a pointer previously acquired from 3712 ** sqlite3_create_filename(), then bad things such as heap 3713 ** corruption or segfaults may occur. The value Y should not be 3714 ** used again after sqlite3_free_filename(Y) has been called. This means 3715 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3716 ** then the corresponding [sqlite3_module.xClose() method should also be 3717 ** invoked prior to calling sqlite3_free_filename(Y). 3718 */ 3719 SQLITE_API char *sqlite3_create_filename( 3720 const char *zDatabase, 3721 const char *zJournal, 3722 const char *zWal, 3723 int nParam, 3724 const char **azParam 3725 ); 3726 SQLITE_API void sqlite3_free_filename(char*); 3727 3728 /* 3729 ** CAPI3REF: Error Codes And Messages 3730 ** METHOD: sqlite3 3731 ** 3732 ** ^If the most recent sqlite3_* API call associated with 3733 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3734 ** returns the numeric [result code] or [extended result code] for that 3735 ** API call. 3736 ** ^The sqlite3_extended_errcode() 3737 ** interface is the same except that it always returns the 3738 ** [extended result code] even when extended result codes are 3739 ** disabled. 3740 ** 3741 ** The values returned by sqlite3_errcode() and/or 3742 ** sqlite3_extended_errcode() might change with each API call. 3743 ** Except, there are some interfaces that are guaranteed to never 3744 ** change the value of the error code. The error-code preserving 3745 ** interfaces are: 3746 ** 3747 ** <ul> 3748 ** <li> sqlite3_errcode() 3749 ** <li> sqlite3_extended_errcode() 3750 ** <li> sqlite3_errmsg() 3751 ** <li> sqlite3_errmsg16() 3752 ** </ul> 3753 ** 3754 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3755 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3756 ** ^(Memory to hold the error message string is managed internally. 3757 ** The application does not need to worry about freeing the result. 3758 ** However, the error string might be overwritten or deallocated by 3759 ** subsequent calls to other SQLite interface functions.)^ 3760 ** 3761 ** ^The sqlite3_errstr() interface returns the English-language text 3762 ** that describes the [result code], as UTF-8. 3763 ** ^(Memory to hold the error message string is managed internally 3764 ** and must not be freed by the application)^. 3765 ** 3766 ** When the serialized [threading mode] is in use, it might be the 3767 ** case that a second error occurs on a separate thread in between 3768 ** the time of the first error and the call to these interfaces. 3769 ** When that happens, the second error will be reported since these 3770 ** interfaces always report the most recent result. To avoid 3771 ** this, each thread can obtain exclusive use of the [database connection] D 3772 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3773 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3774 ** all calls to the interfaces listed here are completed. 3775 ** 3776 ** If an interface fails with SQLITE_MISUSE, that means the interface 3777 ** was invoked incorrectly by the application. In that case, the 3778 ** error code and message may or may not be set. 3779 */ 3780 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3781 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3782 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3783 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3784 SQLITE_API const char *sqlite3_errstr(int); 3785 3786 /* 3787 ** CAPI3REF: Prepared Statement Object 3788 ** KEYWORDS: {prepared statement} {prepared statements} 3789 ** 3790 ** An instance of this object represents a single SQL statement that 3791 ** has been compiled into binary form and is ready to be evaluated. 3792 ** 3793 ** Think of each SQL statement as a separate computer program. The 3794 ** original SQL text is source code. A prepared statement object 3795 ** is the compiled object code. All SQL must be converted into a 3796 ** prepared statement before it can be run. 3797 ** 3798 ** The life-cycle of a prepared statement object usually goes like this: 3799 ** 3800 ** <ol> 3801 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3802 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3803 ** interfaces. 3804 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3805 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3806 ** to step 2. Do this zero or more times. 3807 ** <li> Destroy the object using [sqlite3_finalize()]. 3808 ** </ol> 3809 */ 3810 typedef struct sqlite3_stmt sqlite3_stmt; 3811 3812 /* 3813 ** CAPI3REF: Run-time Limits 3814 ** METHOD: sqlite3 3815 ** 3816 ** ^(This interface allows the size of various constructs to be limited 3817 ** on a connection by connection basis. The first parameter is the 3818 ** [database connection] whose limit is to be set or queried. The 3819 ** second parameter is one of the [limit categories] that define a 3820 ** class of constructs to be size limited. The third parameter is the 3821 ** new limit for that construct.)^ 3822 ** 3823 ** ^If the new limit is a negative number, the limit is unchanged. 3824 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3825 ** [limits | hard upper bound] 3826 ** set at compile-time by a C preprocessor macro called 3827 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3828 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3829 ** ^Attempts to increase a limit above its hard upper bound are 3830 ** silently truncated to the hard upper bound. 3831 ** 3832 ** ^Regardless of whether or not the limit was changed, the 3833 ** [sqlite3_limit()] interface returns the prior value of the limit. 3834 ** ^Hence, to find the current value of a limit without changing it, 3835 ** simply invoke this interface with the third parameter set to -1. 3836 ** 3837 ** Run-time limits are intended for use in applications that manage 3838 ** both their own internal database and also databases that are controlled 3839 ** by untrusted external sources. An example application might be a 3840 ** web browser that has its own databases for storing history and 3841 ** separate databases controlled by JavaScript applications downloaded 3842 ** off the Internet. The internal databases can be given the 3843 ** large, default limits. Databases managed by external sources can 3844 ** be given much smaller limits designed to prevent a denial of service 3845 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3846 ** interface to further control untrusted SQL. The size of the database 3847 ** created by an untrusted script can be contained using the 3848 ** [max_page_count] [PRAGMA]. 3849 ** 3850 ** New run-time limit categories may be added in future releases. 3851 */ 3852 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3853 3854 /* 3855 ** CAPI3REF: Run-Time Limit Categories 3856 ** KEYWORDS: {limit category} {*limit categories} 3857 ** 3858 ** These constants define various performance limits 3859 ** that can be lowered at run-time using [sqlite3_limit()]. 3860 ** The synopsis of the meanings of the various limits is shown below. 3861 ** Additional information is available at [limits | Limits in SQLite]. 3862 ** 3863 ** <dl> 3864 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3865 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3866 ** 3867 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3868 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3869 ** 3870 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3871 ** <dd>The maximum number of columns in a table definition or in the 3872 ** result set of a [SELECT] or the maximum number of columns in an index 3873 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3874 ** 3875 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3876 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3877 ** 3878 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3879 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3880 ** 3881 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3882 ** <dd>The maximum number of instructions in a virtual machine program 3883 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3884 ** the equivalent tries to allocate space for more than this many opcodes 3885 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3886 ** 3887 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3888 ** <dd>The maximum number of arguments on a function.</dd>)^ 3889 ** 3890 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3891 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3892 ** 3893 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3894 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3895 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3896 ** [GLOB] operators.</dd>)^ 3897 ** 3898 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3899 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3900 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3901 ** 3902 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3903 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3904 ** 3905 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3906 ** <dd>The maximum number of auxiliary worker threads that a single 3907 ** [prepared statement] may start.</dd>)^ 3908 ** </dl> 3909 */ 3910 #define SQLITE_LIMIT_LENGTH 0 3911 #define SQLITE_LIMIT_SQL_LENGTH 1 3912 #define SQLITE_LIMIT_COLUMN 2 3913 #define SQLITE_LIMIT_EXPR_DEPTH 3 3914 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3915 #define SQLITE_LIMIT_VDBE_OP 5 3916 #define SQLITE_LIMIT_FUNCTION_ARG 6 3917 #define SQLITE_LIMIT_ATTACHED 7 3918 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3919 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3920 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3921 #define SQLITE_LIMIT_WORKER_THREADS 11 3922 3923 /* 3924 ** CAPI3REF: Prepare Flags 3925 ** 3926 ** These constants define various flags that can be passed into 3927 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3928 ** [sqlite3_prepare16_v3()] interfaces. 3929 ** 3930 ** New flags may be added in future releases of SQLite. 3931 ** 3932 ** <dl> 3933 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3934 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3935 ** that the prepared statement will be retained for a long time and 3936 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3937 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3938 ** be used just once or at most a few times and then destroyed using 3939 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3940 ** on this hint by avoiding the use of [lookaside memory] so as not to 3941 ** deplete the limited store of lookaside memory. Future versions of 3942 ** SQLite may act on this hint differently. 3943 ** 3944 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3945 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3946 ** to be required for any prepared statement that wanted to use the 3947 ** [sqlite3_normalized_sql()] interface. However, the 3948 ** [sqlite3_normalized_sql()] interface is now available to all 3949 ** prepared statements, regardless of whether or not they use this 3950 ** flag. 3951 ** 3952 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3953 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3954 ** to return an error (error code SQLITE_ERROR) if the statement uses 3955 ** any virtual tables. 3956 ** </dl> 3957 */ 3958 #define SQLITE_PREPARE_PERSISTENT 0x01 3959 #define SQLITE_PREPARE_NORMALIZE 0x02 3960 #define SQLITE_PREPARE_NO_VTAB 0x04 3961 3962 /* 3963 ** CAPI3REF: Compiling An SQL Statement 3964 ** KEYWORDS: {SQL statement compiler} 3965 ** METHOD: sqlite3 3966 ** CONSTRUCTOR: sqlite3_stmt 3967 ** 3968 ** To execute an SQL statement, it must first be compiled into a byte-code 3969 ** program using one of these routines. Or, in other words, these routines 3970 ** are constructors for the [prepared statement] object. 3971 ** 3972 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3973 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3974 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3975 ** for special purposes. 3976 ** 3977 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3978 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3979 ** as a convenience. The UTF-16 interfaces work by converting the 3980 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3981 ** 3982 ** The first argument, "db", is a [database connection] obtained from a 3983 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3984 ** [sqlite3_open16()]. The database connection must not have been closed. 3985 ** 3986 ** The second argument, "zSql", is the statement to be compiled, encoded 3987 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3988 ** and sqlite3_prepare_v3() 3989 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3990 ** and sqlite3_prepare16_v3() use UTF-16. 3991 ** 3992 ** ^If the nByte argument is negative, then zSql is read up to the 3993 ** first zero terminator. ^If nByte is positive, then it is the 3994 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3995 ** statement is generated. 3996 ** If the caller knows that the supplied string is nul-terminated, then 3997 ** there is a small performance advantage to passing an nByte parameter that 3998 ** is the number of bytes in the input string <i>including</i> 3999 ** the nul-terminator. 4000 ** 4001 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4002 ** past the end of the first SQL statement in zSql. These routines only 4003 ** compile the first statement in zSql, so *pzTail is left pointing to 4004 ** what remains uncompiled. 4005 ** 4006 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4007 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4008 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4009 ** string or a comment) then *ppStmt is set to NULL. 4010 ** The calling procedure is responsible for deleting the compiled 4011 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4012 ** ppStmt may not be NULL. 4013 ** 4014 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4015 ** otherwise an [error code] is returned. 4016 ** 4017 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4018 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4019 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4020 ** are retained for backwards compatibility, but their use is discouraged. 4021 ** ^In the "vX" interfaces, the prepared statement 4022 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4023 ** original SQL text. This causes the [sqlite3_step()] interface to 4024 ** behave differently in three ways: 4025 ** 4026 ** <ol> 4027 ** <li> 4028 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4029 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4030 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4031 ** retries will occur before sqlite3_step() gives up and returns an error. 4032 ** </li> 4033 ** 4034 ** <li> 4035 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4036 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4037 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4038 ** and the application would have to make a second call to [sqlite3_reset()] 4039 ** in order to find the underlying cause of the problem. With the "v2" prepare 4040 ** interfaces, the underlying reason for the error is returned immediately. 4041 ** </li> 4042 ** 4043 ** <li> 4044 ** ^If the specific value bound to a [parameter | host parameter] in the 4045 ** WHERE clause might influence the choice of query plan for a statement, 4046 ** then the statement will be automatically recompiled, as if there had been 4047 ** a schema change, on the first [sqlite3_step()] call following any change 4048 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4049 ** ^The specific value of a WHERE-clause [parameter] might influence the 4050 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4051 ** or [GLOB] operator or if the parameter is compared to an indexed column 4052 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4053 ** </li> 4054 ** </ol> 4055 ** 4056 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4057 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4058 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4059 ** sqlite3_prepare_v2() interface works exactly the same as 4060 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4061 */ 4062 SQLITE_API int sqlite3_prepare( 4063 sqlite3 *db, /* Database handle */ 4064 const char *zSql, /* SQL statement, UTF-8 encoded */ 4065 int nByte, /* Maximum length of zSql in bytes. */ 4066 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4067 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4068 ); 4069 SQLITE_API int sqlite3_prepare_v2( 4070 sqlite3 *db, /* Database handle */ 4071 const char *zSql, /* SQL statement, UTF-8 encoded */ 4072 int nByte, /* Maximum length of zSql in bytes. */ 4073 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4074 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4075 ); 4076 SQLITE_API int sqlite3_prepare_v3( 4077 sqlite3 *db, /* Database handle */ 4078 const char *zSql, /* SQL statement, UTF-8 encoded */ 4079 int nByte, /* Maximum length of zSql in bytes. */ 4080 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4081 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4082 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4083 ); 4084 SQLITE_API int sqlite3_prepare16( 4085 sqlite3 *db, /* Database handle */ 4086 const void *zSql, /* SQL statement, UTF-16 encoded */ 4087 int nByte, /* Maximum length of zSql in bytes. */ 4088 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4089 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4090 ); 4091 SQLITE_API int sqlite3_prepare16_v2( 4092 sqlite3 *db, /* Database handle */ 4093 const void *zSql, /* SQL statement, UTF-16 encoded */ 4094 int nByte, /* Maximum length of zSql in bytes. */ 4095 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4096 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4097 ); 4098 SQLITE_API int sqlite3_prepare16_v3( 4099 sqlite3 *db, /* Database handle */ 4100 const void *zSql, /* SQL statement, UTF-16 encoded */ 4101 int nByte, /* Maximum length of zSql in bytes. */ 4102 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4103 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4104 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4105 ); 4106 4107 /* 4108 ** CAPI3REF: Retrieving Statement SQL 4109 ** METHOD: sqlite3_stmt 4110 ** 4111 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4112 ** SQL text used to create [prepared statement] P if P was 4113 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4114 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4115 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4116 ** string containing the SQL text of prepared statement P with 4117 ** [bound parameters] expanded. 4118 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4119 ** string containing the normalized SQL text of prepared statement P. The 4120 ** semantics used to normalize a SQL statement are unspecified and subject 4121 ** to change. At a minimum, literal values will be replaced with suitable 4122 ** placeholders. 4123 ** 4124 ** ^(For example, if a prepared statement is created using the SQL 4125 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4126 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4127 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4128 ** will return "SELECT 2345,NULL".)^ 4129 ** 4130 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4131 ** is available to hold the result, or if the result would exceed the 4132 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4133 ** 4134 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4135 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4136 ** option causes sqlite3_expanded_sql() to always return NULL. 4137 ** 4138 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4139 ** are managed by SQLite and are automatically freed when the prepared 4140 ** statement is finalized. 4141 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4142 ** is obtained from [sqlite3_malloc()] and must be free by the application 4143 ** by passing it to [sqlite3_free()]. 4144 */ 4145 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4146 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4147 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4148 4149 /* 4150 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4151 ** METHOD: sqlite3_stmt 4152 ** 4153 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4154 ** and only if the [prepared statement] X makes no direct changes to 4155 ** the content of the database file. 4156 ** 4157 ** Note that [application-defined SQL functions] or 4158 ** [virtual tables] might change the database indirectly as a side effect. 4159 ** ^(For example, if an application defines a function "eval()" that 4160 ** calls [sqlite3_exec()], then the following SQL statement would 4161 ** change the database file through side-effects: 4162 ** 4163 ** <blockquote><pre> 4164 ** SELECT eval('DELETE FROM t1') FROM t2; 4165 ** </pre></blockquote> 4166 ** 4167 ** But because the [SELECT] statement does not change the database file 4168 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4169 ** 4170 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4171 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4172 ** since the statements themselves do not actually modify the database but 4173 ** rather they control the timing of when other statements modify the 4174 ** database. ^The [ATTACH] and [DETACH] statements also cause 4175 ** sqlite3_stmt_readonly() to return true since, while those statements 4176 ** change the configuration of a database connection, they do not make 4177 ** changes to the content of the database files on disk. 4178 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4179 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4180 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4181 ** sqlite3_stmt_readonly() returns false for those commands. 4182 */ 4183 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4184 4185 /* 4186 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4187 ** METHOD: sqlite3_stmt 4188 ** 4189 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4190 ** prepared statement S is an EXPLAIN statement, or 2 if the 4191 ** statement S is an EXPLAIN QUERY PLAN. 4192 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4193 ** an ordinary statement or a NULL pointer. 4194 */ 4195 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4196 4197 /* 4198 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4199 ** METHOD: sqlite3_stmt 4200 ** 4201 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4202 ** [prepared statement] S has been stepped at least once using 4203 ** [sqlite3_step(S)] but has neither run to completion (returned 4204 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4205 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4206 ** interface returns false if S is a NULL pointer. If S is not a 4207 ** NULL pointer and is not a pointer to a valid [prepared statement] 4208 ** object, then the behavior is undefined and probably undesirable. 4209 ** 4210 ** This interface can be used in combination [sqlite3_next_stmt()] 4211 ** to locate all prepared statements associated with a database 4212 ** connection that are in need of being reset. This can be used, 4213 ** for example, in diagnostic routines to search for prepared 4214 ** statements that are holding a transaction open. 4215 */ 4216 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4217 4218 /* 4219 ** CAPI3REF: Dynamically Typed Value Object 4220 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4221 ** 4222 ** SQLite uses the sqlite3_value object to represent all values 4223 ** that can be stored in a database table. SQLite uses dynamic typing 4224 ** for the values it stores. ^Values stored in sqlite3_value objects 4225 ** can be integers, floating point values, strings, BLOBs, or NULL. 4226 ** 4227 ** An sqlite3_value object may be either "protected" or "unprotected". 4228 ** Some interfaces require a protected sqlite3_value. Other interfaces 4229 ** will accept either a protected or an unprotected sqlite3_value. 4230 ** Every interface that accepts sqlite3_value arguments specifies 4231 ** whether or not it requires a protected sqlite3_value. The 4232 ** [sqlite3_value_dup()] interface can be used to construct a new 4233 ** protected sqlite3_value from an unprotected sqlite3_value. 4234 ** 4235 ** The terms "protected" and "unprotected" refer to whether or not 4236 ** a mutex is held. An internal mutex is held for a protected 4237 ** sqlite3_value object but no mutex is held for an unprotected 4238 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4239 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4240 ** or if SQLite is run in one of reduced mutex modes 4241 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4242 ** then there is no distinction between protected and unprotected 4243 ** sqlite3_value objects and they can be used interchangeably. However, 4244 ** for maximum code portability it is recommended that applications 4245 ** still make the distinction between protected and unprotected 4246 ** sqlite3_value objects even when not strictly required. 4247 ** 4248 ** ^The sqlite3_value objects that are passed as parameters into the 4249 ** implementation of [application-defined SQL functions] are protected. 4250 ** ^The sqlite3_value object returned by 4251 ** [sqlite3_column_value()] is unprotected. 4252 ** Unprotected sqlite3_value objects may only be used as arguments 4253 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4254 ** [sqlite3_value_dup()]. 4255 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4256 ** interfaces require protected sqlite3_value objects. 4257 */ 4258 typedef struct sqlite3_value sqlite3_value; 4259 4260 /* 4261 ** CAPI3REF: SQL Function Context Object 4262 ** 4263 ** The context in which an SQL function executes is stored in an 4264 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4265 ** is always first parameter to [application-defined SQL functions]. 4266 ** The application-defined SQL function implementation will pass this 4267 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4268 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4269 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4270 ** and/or [sqlite3_set_auxdata()]. 4271 */ 4272 typedef struct sqlite3_context sqlite3_context; 4273 4274 /* 4275 ** CAPI3REF: Binding Values To Prepared Statements 4276 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4277 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4278 ** METHOD: sqlite3_stmt 4279 ** 4280 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4281 ** literals may be replaced by a [parameter] that matches one of following 4282 ** templates: 4283 ** 4284 ** <ul> 4285 ** <li> ? 4286 ** <li> ?NNN 4287 ** <li> :VVV 4288 ** <li> @VVV 4289 ** <li> $VVV 4290 ** </ul> 4291 ** 4292 ** In the templates above, NNN represents an integer literal, 4293 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4294 ** parameters (also called "host parameter names" or "SQL parameters") 4295 ** can be set using the sqlite3_bind_*() routines defined here. 4296 ** 4297 ** ^The first argument to the sqlite3_bind_*() routines is always 4298 ** a pointer to the [sqlite3_stmt] object returned from 4299 ** [sqlite3_prepare_v2()] or its variants. 4300 ** 4301 ** ^The second argument is the index of the SQL parameter to be set. 4302 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4303 ** SQL parameter is used more than once, second and subsequent 4304 ** occurrences have the same index as the first occurrence. 4305 ** ^The index for named parameters can be looked up using the 4306 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4307 ** for "?NNN" parameters is the value of NNN. 4308 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4309 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4310 ** 4311 ** ^The third argument is the value to bind to the parameter. 4312 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4313 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4314 ** is ignored and the end result is the same as sqlite3_bind_null(). 4315 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4316 ** it should be a pointer to well-formed UTF8 text. 4317 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4318 ** it should be a pointer to well-formed UTF16 text. 4319 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4320 ** it should be a pointer to a well-formed unicode string that is 4321 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4322 ** otherwise. 4323 ** 4324 ** [[byte-order determination rules]] ^The byte-order of 4325 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4326 ** found in first character, which is removed, or in the absence of a BOM 4327 ** the byte order is the native byte order of the host 4328 ** machine for sqlite3_bind_text16() or the byte order specified in 4329 ** the 6th parameter for sqlite3_bind_text64().)^ 4330 ** ^If UTF16 input text contains invalid unicode 4331 ** characters, then SQLite might change those invalid characters 4332 ** into the unicode replacement character: U+FFFD. 4333 ** 4334 ** ^(In those routines that have a fourth argument, its value is the 4335 ** number of bytes in the parameter. To be clear: the value is the 4336 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4337 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4338 ** is negative, then the length of the string is 4339 ** the number of bytes up to the first zero terminator. 4340 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4341 ** the behavior is undefined. 4342 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4343 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4344 ** that parameter must be the byte offset 4345 ** where the NUL terminator would occur assuming the string were NUL 4346 ** terminated. If any NUL characters occurs at byte offsets less than 4347 ** the value of the fourth parameter then the resulting string value will 4348 ** contain embedded NULs. The result of expressions involving strings 4349 ** with embedded NULs is undefined. 4350 ** 4351 ** ^The fifth argument to the BLOB and string binding interfaces 4352 ** is a destructor used to dispose of the BLOB or 4353 ** string after SQLite has finished with it. ^The destructor is called 4354 ** to dispose of the BLOB or string even if the call to the bind API fails, 4355 ** except the destructor is not called if the third parameter is a NULL 4356 ** pointer or the fourth parameter is negative. 4357 ** ^If the fifth argument is 4358 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4359 ** information is in static, unmanaged space and does not need to be freed. 4360 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4361 ** SQLite makes its own private copy of the data immediately, before 4362 ** the sqlite3_bind_*() routine returns. 4363 ** 4364 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4365 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4366 ** to specify the encoding of the text in the third parameter. If 4367 ** the sixth argument to sqlite3_bind_text64() is not one of the 4368 ** allowed values shown above, or if the text encoding is different 4369 ** from the encoding specified by the sixth parameter, then the behavior 4370 ** is undefined. 4371 ** 4372 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4373 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4374 ** (just an integer to hold its size) while it is being processed. 4375 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4376 ** content is later written using 4377 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4378 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4379 ** 4380 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4381 ** [prepared statement] S to have an SQL value of NULL, but to also be 4382 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4383 ** a pointer to a destructor function for P. ^SQLite will invoke the 4384 ** destructor D with a single argument of P when it is finished using 4385 ** P. The T parameter should be a static string, preferably a string 4386 ** literal. The sqlite3_bind_pointer() routine is part of the 4387 ** [pointer passing interface] added for SQLite 3.20.0. 4388 ** 4389 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4390 ** for the [prepared statement] or with a prepared statement for which 4391 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4392 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4393 ** routine is passed a [prepared statement] that has been finalized, the 4394 ** result is undefined and probably harmful. 4395 ** 4396 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4397 ** ^Unbound parameters are interpreted as NULL. 4398 ** 4399 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4400 ** [error code] if anything goes wrong. 4401 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4402 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4403 ** [SQLITE_MAX_LENGTH]. 4404 ** ^[SQLITE_RANGE] is returned if the parameter 4405 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4406 ** 4407 ** See also: [sqlite3_bind_parameter_count()], 4408 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4409 */ 4410 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4411 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4412 void(*)(void*)); 4413 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4414 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4415 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4416 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4417 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4418 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4419 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4420 void(*)(void*), unsigned char encoding); 4421 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4422 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4423 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4424 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4425 4426 /* 4427 ** CAPI3REF: Number Of SQL Parameters 4428 ** METHOD: sqlite3_stmt 4429 ** 4430 ** ^This routine can be used to find the number of [SQL parameters] 4431 ** in a [prepared statement]. SQL parameters are tokens of the 4432 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4433 ** placeholders for values that are [sqlite3_bind_blob | bound] 4434 ** to the parameters at a later time. 4435 ** 4436 ** ^(This routine actually returns the index of the largest (rightmost) 4437 ** parameter. For all forms except ?NNN, this will correspond to the 4438 ** number of unique parameters. If parameters of the ?NNN form are used, 4439 ** there may be gaps in the list.)^ 4440 ** 4441 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4442 ** [sqlite3_bind_parameter_name()], and 4443 ** [sqlite3_bind_parameter_index()]. 4444 */ 4445 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4446 4447 /* 4448 ** CAPI3REF: Name Of A Host Parameter 4449 ** METHOD: sqlite3_stmt 4450 ** 4451 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4452 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4453 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4454 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4455 ** respectively. 4456 ** In other words, the initial ":" or "$" or "@" or "?" 4457 ** is included as part of the name.)^ 4458 ** ^Parameters of the form "?" without a following integer have no name 4459 ** and are referred to as "nameless" or "anonymous parameters". 4460 ** 4461 ** ^The first host parameter has an index of 1, not 0. 4462 ** 4463 ** ^If the value N is out of range or if the N-th parameter is 4464 ** nameless, then NULL is returned. ^The returned string is 4465 ** always in UTF-8 encoding even if the named parameter was 4466 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4467 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4468 ** 4469 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4470 ** [sqlite3_bind_parameter_count()], and 4471 ** [sqlite3_bind_parameter_index()]. 4472 */ 4473 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4474 4475 /* 4476 ** CAPI3REF: Index Of A Parameter With A Given Name 4477 ** METHOD: sqlite3_stmt 4478 ** 4479 ** ^Return the index of an SQL parameter given its name. ^The 4480 ** index value returned is suitable for use as the second 4481 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4482 ** is returned if no matching parameter is found. ^The parameter 4483 ** name must be given in UTF-8 even if the original statement 4484 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4485 ** [sqlite3_prepare16_v3()]. 4486 ** 4487 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4488 ** [sqlite3_bind_parameter_count()], and 4489 ** [sqlite3_bind_parameter_name()]. 4490 */ 4491 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4492 4493 /* 4494 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4495 ** METHOD: sqlite3_stmt 4496 ** 4497 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4498 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4499 ** ^Use this routine to reset all host parameters to NULL. 4500 */ 4501 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4502 4503 /* 4504 ** CAPI3REF: Number Of Columns In A Result Set 4505 ** METHOD: sqlite3_stmt 4506 ** 4507 ** ^Return the number of columns in the result set returned by the 4508 ** [prepared statement]. ^If this routine returns 0, that means the 4509 ** [prepared statement] returns no data (for example an [UPDATE]). 4510 ** ^However, just because this routine returns a positive number does not 4511 ** mean that one or more rows of data will be returned. ^A SELECT statement 4512 ** will always have a positive sqlite3_column_count() but depending on the 4513 ** WHERE clause constraints and the table content, it might return no rows. 4514 ** 4515 ** See also: [sqlite3_data_count()] 4516 */ 4517 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4518 4519 /* 4520 ** CAPI3REF: Column Names In A Result Set 4521 ** METHOD: sqlite3_stmt 4522 ** 4523 ** ^These routines return the name assigned to a particular column 4524 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4525 ** interface returns a pointer to a zero-terminated UTF-8 string 4526 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4527 ** UTF-16 string. ^The first parameter is the [prepared statement] 4528 ** that implements the [SELECT] statement. ^The second parameter is the 4529 ** column number. ^The leftmost column is number 0. 4530 ** 4531 ** ^The returned string pointer is valid until either the [prepared statement] 4532 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4533 ** reprepared by the first call to [sqlite3_step()] for a particular run 4534 ** or until the next call to 4535 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4536 ** 4537 ** ^If sqlite3_malloc() fails during the processing of either routine 4538 ** (for example during a conversion from UTF-8 to UTF-16) then a 4539 ** NULL pointer is returned. 4540 ** 4541 ** ^The name of a result column is the value of the "AS" clause for 4542 ** that column, if there is an AS clause. If there is no AS clause 4543 ** then the name of the column is unspecified and may change from 4544 ** one release of SQLite to the next. 4545 */ 4546 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4547 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4548 4549 /* 4550 ** CAPI3REF: Source Of Data In A Query Result 4551 ** METHOD: sqlite3_stmt 4552 ** 4553 ** ^These routines provide a means to determine the database, table, and 4554 ** table column that is the origin of a particular result column in 4555 ** [SELECT] statement. 4556 ** ^The name of the database or table or column can be returned as 4557 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4558 ** the database name, the _table_ routines return the table name, and 4559 ** the origin_ routines return the column name. 4560 ** ^The returned string is valid until the [prepared statement] is destroyed 4561 ** using [sqlite3_finalize()] or until the statement is automatically 4562 ** reprepared by the first call to [sqlite3_step()] for a particular run 4563 ** or until the same information is requested 4564 ** again in a different encoding. 4565 ** 4566 ** ^The names returned are the original un-aliased names of the 4567 ** database, table, and column. 4568 ** 4569 ** ^The first argument to these interfaces is a [prepared statement]. 4570 ** ^These functions return information about the Nth result column returned by 4571 ** the statement, where N is the second function argument. 4572 ** ^The left-most column is column 0 for these routines. 4573 ** 4574 ** ^If the Nth column returned by the statement is an expression or 4575 ** subquery and is not a column value, then all of these functions return 4576 ** NULL. ^These routines might also return NULL if a memory allocation error 4577 ** occurs. ^Otherwise, they return the name of the attached database, table, 4578 ** or column that query result column was extracted from. 4579 ** 4580 ** ^As with all other SQLite APIs, those whose names end with "16" return 4581 ** UTF-16 encoded strings and the other functions return UTF-8. 4582 ** 4583 ** ^These APIs are only available if the library was compiled with the 4584 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4585 ** 4586 ** If two or more threads call one or more 4587 ** [sqlite3_column_database_name | column metadata interfaces] 4588 ** for the same [prepared statement] and result column 4589 ** at the same time then the results are undefined. 4590 */ 4591 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4592 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4593 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4594 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4595 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4596 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4597 4598 /* 4599 ** CAPI3REF: Declared Datatype Of A Query Result 4600 ** METHOD: sqlite3_stmt 4601 ** 4602 ** ^(The first parameter is a [prepared statement]. 4603 ** If this statement is a [SELECT] statement and the Nth column of the 4604 ** returned result set of that [SELECT] is a table column (not an 4605 ** expression or subquery) then the declared type of the table 4606 ** column is returned.)^ ^If the Nth column of the result set is an 4607 ** expression or subquery, then a NULL pointer is returned. 4608 ** ^The returned string is always UTF-8 encoded. 4609 ** 4610 ** ^(For example, given the database schema: 4611 ** 4612 ** CREATE TABLE t1(c1 VARIANT); 4613 ** 4614 ** and the following statement to be compiled: 4615 ** 4616 ** SELECT c1 + 1, c1 FROM t1; 4617 ** 4618 ** this routine would return the string "VARIANT" for the second result 4619 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4620 ** 4621 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4622 ** is declared to contain a particular type does not mean that the 4623 ** data stored in that column is of the declared type. SQLite is 4624 ** strongly typed, but the typing is dynamic not static. ^Type 4625 ** is associated with individual values, not with the containers 4626 ** used to hold those values. 4627 */ 4628 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4629 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4630 4631 /* 4632 ** CAPI3REF: Evaluate An SQL Statement 4633 ** METHOD: sqlite3_stmt 4634 ** 4635 ** After a [prepared statement] has been prepared using any of 4636 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4637 ** or [sqlite3_prepare16_v3()] or one of the legacy 4638 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4639 ** must be called one or more times to evaluate the statement. 4640 ** 4641 ** The details of the behavior of the sqlite3_step() interface depend 4642 ** on whether the statement was prepared using the newer "vX" interfaces 4643 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4644 ** [sqlite3_prepare16_v2()] or the older legacy 4645 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4646 ** new "vX" interface is recommended for new applications but the legacy 4647 ** interface will continue to be supported. 4648 ** 4649 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4650 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4651 ** ^With the "v2" interface, any of the other [result codes] or 4652 ** [extended result codes] might be returned as well. 4653 ** 4654 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4655 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4656 ** or occurs outside of an explicit transaction, then you can retry the 4657 ** statement. If the statement is not a [COMMIT] and occurs within an 4658 ** explicit transaction then you should rollback the transaction before 4659 ** continuing. 4660 ** 4661 ** ^[SQLITE_DONE] means that the statement has finished executing 4662 ** successfully. sqlite3_step() should not be called again on this virtual 4663 ** machine without first calling [sqlite3_reset()] to reset the virtual 4664 ** machine back to its initial state. 4665 ** 4666 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4667 ** is returned each time a new row of data is ready for processing by the 4668 ** caller. The values may be accessed using the [column access functions]. 4669 ** sqlite3_step() is called again to retrieve the next row of data. 4670 ** 4671 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4672 ** violation) has occurred. sqlite3_step() should not be called again on 4673 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4674 ** ^With the legacy interface, a more specific error code (for example, 4675 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4676 ** can be obtained by calling [sqlite3_reset()] on the 4677 ** [prepared statement]. ^In the "v2" interface, 4678 ** the more specific error code is returned directly by sqlite3_step(). 4679 ** 4680 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4681 ** Perhaps it was called on a [prepared statement] that has 4682 ** already been [sqlite3_finalize | finalized] or on one that had 4683 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4684 ** be the case that the same database connection is being used by two or 4685 ** more threads at the same moment in time. 4686 ** 4687 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4688 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4689 ** other than [SQLITE_ROW] before any subsequent invocation of 4690 ** sqlite3_step(). Failure to reset the prepared statement using 4691 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4692 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4693 ** sqlite3_step() began 4694 ** calling [sqlite3_reset()] automatically in this circumstance rather 4695 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4696 ** break because any application that ever receives an SQLITE_MISUSE error 4697 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4698 ** can be used to restore the legacy behavior. 4699 ** 4700 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4701 ** API always returns a generic error code, [SQLITE_ERROR], following any 4702 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4703 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4704 ** specific [error codes] that better describes the error. 4705 ** We admit that this is a goofy design. The problem has been fixed 4706 ** with the "v2" interface. If you prepare all of your SQL statements 4707 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4708 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4709 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4710 ** then the more specific [error codes] are returned directly 4711 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4712 */ 4713 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4714 4715 /* 4716 ** CAPI3REF: Number of columns in a result set 4717 ** METHOD: sqlite3_stmt 4718 ** 4719 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4720 ** current row of the result set of [prepared statement] P. 4721 ** ^If prepared statement P does not have results ready to return 4722 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4723 ** interfaces) then sqlite3_data_count(P) returns 0. 4724 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4725 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4726 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4727 ** will return non-zero if previous call to [sqlite3_step](P) returned 4728 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4729 ** where it always returns zero since each step of that multi-step 4730 ** pragma returns 0 columns of data. 4731 ** 4732 ** See also: [sqlite3_column_count()] 4733 */ 4734 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4735 4736 /* 4737 ** CAPI3REF: Fundamental Datatypes 4738 ** KEYWORDS: SQLITE_TEXT 4739 ** 4740 ** ^(Every value in SQLite has one of five fundamental datatypes: 4741 ** 4742 ** <ul> 4743 ** <li> 64-bit signed integer 4744 ** <li> 64-bit IEEE floating point number 4745 ** <li> string 4746 ** <li> BLOB 4747 ** <li> NULL 4748 ** </ul>)^ 4749 ** 4750 ** These constants are codes for each of those types. 4751 ** 4752 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4753 ** for a completely different meaning. Software that links against both 4754 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4755 ** SQLITE_TEXT. 4756 */ 4757 #define SQLITE_INTEGER 1 4758 #define SQLITE_FLOAT 2 4759 #define SQLITE_BLOB 4 4760 #define SQLITE_NULL 5 4761 #ifdef SQLITE_TEXT 4762 # undef SQLITE_TEXT 4763 #else 4764 # define SQLITE_TEXT 3 4765 #endif 4766 #define SQLITE3_TEXT 3 4767 4768 /* 4769 ** CAPI3REF: Result Values From A Query 4770 ** KEYWORDS: {column access functions} 4771 ** METHOD: sqlite3_stmt 4772 ** 4773 ** <b>Summary:</b> 4774 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4775 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4776 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4777 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4778 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4779 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4780 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4781 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4782 ** [sqlite3_value|unprotected sqlite3_value] object. 4783 ** <tr><td> <td> <td> 4784 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4785 ** or a UTF-8 TEXT result in bytes 4786 ** <tr><td><b>sqlite3_column_bytes16 </b> 4787 ** <td>→ <td>Size of UTF-16 4788 ** TEXT in bytes 4789 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4790 ** datatype of the result 4791 ** </table></blockquote> 4792 ** 4793 ** <b>Details:</b> 4794 ** 4795 ** ^These routines return information about a single column of the current 4796 ** result row of a query. ^In every case the first argument is a pointer 4797 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4798 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4799 ** and the second argument is the index of the column for which information 4800 ** should be returned. ^The leftmost column of the result set has the index 0. 4801 ** ^The number of columns in the result can be determined using 4802 ** [sqlite3_column_count()]. 4803 ** 4804 ** If the SQL statement does not currently point to a valid row, or if the 4805 ** column index is out of range, the result is undefined. 4806 ** These routines may only be called when the most recent call to 4807 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4808 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4809 ** If any of these routines are called after [sqlite3_reset()] or 4810 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4811 ** something other than [SQLITE_ROW], the results are undefined. 4812 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4813 ** are called from a different thread while any of these routines 4814 ** are pending, then the results are undefined. 4815 ** 4816 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4817 ** each return the value of a result column in a specific data format. If 4818 ** the result column is not initially in the requested format (for example, 4819 ** if the query returns an integer but the sqlite3_column_text() interface 4820 ** is used to extract the value) then an automatic type conversion is performed. 4821 ** 4822 ** ^The sqlite3_column_type() routine returns the 4823 ** [SQLITE_INTEGER | datatype code] for the initial data type 4824 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4825 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4826 ** The return value of sqlite3_column_type() can be used to decide which 4827 ** of the first six interface should be used to extract the column value. 4828 ** The value returned by sqlite3_column_type() is only meaningful if no 4829 ** automatic type conversions have occurred for the value in question. 4830 ** After a type conversion, the result of calling sqlite3_column_type() 4831 ** is undefined, though harmless. Future 4832 ** versions of SQLite may change the behavior of sqlite3_column_type() 4833 ** following a type conversion. 4834 ** 4835 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4836 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4837 ** of that BLOB or string. 4838 ** 4839 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4840 ** routine returns the number of bytes in that BLOB or string. 4841 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4842 ** the string to UTF-8 and then returns the number of bytes. 4843 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4844 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4845 ** the number of bytes in that string. 4846 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4847 ** 4848 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4849 ** routine returns the number of bytes in that BLOB or string. 4850 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4851 ** the string to UTF-16 and then returns the number of bytes. 4852 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4853 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4854 ** the number of bytes in that string. 4855 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4856 ** 4857 ** ^The values returned by [sqlite3_column_bytes()] and 4858 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4859 ** of the string. ^For clarity: the values returned by 4860 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4861 ** bytes in the string, not the number of characters. 4862 ** 4863 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4864 ** even empty strings, are always zero-terminated. ^The return 4865 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4866 ** 4867 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4868 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4869 ** an unprotected sqlite3_value object may only be used safely with 4870 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4871 ** If the [unprotected sqlite3_value] object returned by 4872 ** [sqlite3_column_value()] is used in any other way, including calls 4873 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4874 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4875 ** Hence, the sqlite3_column_value() interface 4876 ** is normally only useful within the implementation of 4877 ** [application-defined SQL functions] or [virtual tables], not within 4878 ** top-level application code. 4879 ** 4880 ** The these routines may attempt to convert the datatype of the result. 4881 ** ^For example, if the internal representation is FLOAT and a text result 4882 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4883 ** conversion automatically. ^(The following table details the conversions 4884 ** that are applied: 4885 ** 4886 ** <blockquote> 4887 ** <table border="1"> 4888 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4889 ** 4890 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4891 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4892 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4893 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4894 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4895 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4896 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4897 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4898 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4899 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4900 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4901 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4902 ** <tr><td> TEXT <td> BLOB <td> No change 4903 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4904 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4905 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4906 ** </table> 4907 ** </blockquote>)^ 4908 ** 4909 ** Note that when type conversions occur, pointers returned by prior 4910 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4911 ** sqlite3_column_text16() may be invalidated. 4912 ** Type conversions and pointer invalidations might occur 4913 ** in the following cases: 4914 ** 4915 ** <ul> 4916 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4917 ** sqlite3_column_text16() is called. A zero-terminator might 4918 ** need to be added to the string.</li> 4919 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4920 ** sqlite3_column_text16() is called. The content must be converted 4921 ** to UTF-16.</li> 4922 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4923 ** sqlite3_column_text() is called. The content must be converted 4924 ** to UTF-8.</li> 4925 ** </ul> 4926 ** 4927 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4928 ** not invalidate a prior pointer, though of course the content of the buffer 4929 ** that the prior pointer references will have been modified. Other kinds 4930 ** of conversion are done in place when it is possible, but sometimes they 4931 ** are not possible and in those cases prior pointers are invalidated. 4932 ** 4933 ** The safest policy is to invoke these routines 4934 ** in one of the following ways: 4935 ** 4936 ** <ul> 4937 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4938 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4939 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4940 ** </ul> 4941 ** 4942 ** In other words, you should call sqlite3_column_text(), 4943 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4944 ** into the desired format, then invoke sqlite3_column_bytes() or 4945 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4946 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4947 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4948 ** with calls to sqlite3_column_bytes(). 4949 ** 4950 ** ^The pointers returned are valid until a type conversion occurs as 4951 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4952 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4953 ** and BLOBs is freed automatically. Do not pass the pointers returned 4954 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4955 ** [sqlite3_free()]. 4956 ** 4957 ** As long as the input parameters are correct, these routines will only 4958 ** fail if an out-of-memory error occurs during a format conversion. 4959 ** Only the following subset of interfaces are subject to out-of-memory 4960 ** errors: 4961 ** 4962 ** <ul> 4963 ** <li> sqlite3_column_blob() 4964 ** <li> sqlite3_column_text() 4965 ** <li> sqlite3_column_text16() 4966 ** <li> sqlite3_column_bytes() 4967 ** <li> sqlite3_column_bytes16() 4968 ** </ul> 4969 ** 4970 ** If an out-of-memory error occurs, then the return value from these 4971 ** routines is the same as if the column had contained an SQL NULL value. 4972 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4973 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4974 ** return value is obtained and before any 4975 ** other SQLite interface is called on the same [database connection]. 4976 */ 4977 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4978 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4979 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4980 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4981 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4982 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4983 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4984 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4985 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4986 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4987 4988 /* 4989 ** CAPI3REF: Destroy A Prepared Statement Object 4990 ** DESTRUCTOR: sqlite3_stmt 4991 ** 4992 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4993 ** ^If the most recent evaluation of the statement encountered no errors 4994 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4995 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4996 ** sqlite3_finalize(S) returns the appropriate [error code] or 4997 ** [extended error code]. 4998 ** 4999 ** ^The sqlite3_finalize(S) routine can be called at any point during 5000 ** the life cycle of [prepared statement] S: 5001 ** before statement S is ever evaluated, after 5002 ** one or more calls to [sqlite3_reset()], or after any call 5003 ** to [sqlite3_step()] regardless of whether or not the statement has 5004 ** completed execution. 5005 ** 5006 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5007 ** 5008 ** The application must finalize every [prepared statement] in order to avoid 5009 ** resource leaks. It is a grievous error for the application to try to use 5010 ** a prepared statement after it has been finalized. Any use of a prepared 5011 ** statement after it has been finalized can result in undefined and 5012 ** undesirable behavior such as segfaults and heap corruption. 5013 */ 5014 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5015 5016 /* 5017 ** CAPI3REF: Reset A Prepared Statement Object 5018 ** METHOD: sqlite3_stmt 5019 ** 5020 ** The sqlite3_reset() function is called to reset a [prepared statement] 5021 ** object back to its initial state, ready to be re-executed. 5022 ** ^Any SQL statement variables that had values bound to them using 5023 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5024 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5025 ** 5026 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5027 ** back to the beginning of its program. 5028 ** 5029 ** ^If the most recent call to [sqlite3_step(S)] for the 5030 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5031 ** or if [sqlite3_step(S)] has never before been called on S, 5032 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5033 ** 5034 ** ^If the most recent call to [sqlite3_step(S)] for the 5035 ** [prepared statement] S indicated an error, then 5036 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5037 ** 5038 ** ^The [sqlite3_reset(S)] interface does not change the values 5039 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5040 */ 5041 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5042 5043 /* 5044 ** CAPI3REF: Create Or Redefine SQL Functions 5045 ** KEYWORDS: {function creation routines} 5046 ** METHOD: sqlite3 5047 ** 5048 ** ^These functions (collectively known as "function creation routines") 5049 ** are used to add SQL functions or aggregates or to redefine the behavior 5050 ** of existing SQL functions or aggregates. The only differences between 5051 ** the three "sqlite3_create_function*" routines are the text encoding 5052 ** expected for the second parameter (the name of the function being 5053 ** created) and the presence or absence of a destructor callback for 5054 ** the application data pointer. Function sqlite3_create_window_function() 5055 ** is similar, but allows the user to supply the extra callback functions 5056 ** needed by [aggregate window functions]. 5057 ** 5058 ** ^The first parameter is the [database connection] to which the SQL 5059 ** function is to be added. ^If an application uses more than one database 5060 ** connection then application-defined SQL functions must be added 5061 ** to each database connection separately. 5062 ** 5063 ** ^The second parameter is the name of the SQL function to be created or 5064 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5065 ** representation, exclusive of the zero-terminator. ^Note that the name 5066 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5067 ** ^Any attempt to create a function with a longer name 5068 ** will result in [SQLITE_MISUSE] being returned. 5069 ** 5070 ** ^The third parameter (nArg) 5071 ** is the number of arguments that the SQL function or 5072 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5073 ** aggregate may take any number of arguments between 0 and the limit 5074 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5075 ** parameter is less than -1 or greater than 127 then the behavior is 5076 ** undefined. 5077 ** 5078 ** ^The fourth parameter, eTextRep, specifies what 5079 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5080 ** its parameters. The application should set this parameter to 5081 ** [SQLITE_UTF16LE] if the function implementation invokes 5082 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5083 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5084 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5085 ** otherwise. ^The same SQL function may be registered multiple times using 5086 ** different preferred text encodings, with different implementations for 5087 ** each encoding. 5088 ** ^When multiple implementations of the same function are available, SQLite 5089 ** will pick the one that involves the least amount of data conversion. 5090 ** 5091 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5092 ** to signal that the function will always return the same result given 5093 ** the same inputs within a single SQL statement. Most SQL functions are 5094 ** deterministic. The built-in [random()] SQL function is an example of a 5095 ** function that is not deterministic. The SQLite query planner is able to 5096 ** perform additional optimizations on deterministic functions, so use 5097 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5098 ** 5099 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5100 ** flag, which if present prevents the function from being invoked from 5101 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5102 ** index expressions, or the WHERE clause of partial indexes. 5103 ** 5104 ** <span style="background-color:#ffff90;"> 5105 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5106 ** all application-defined SQL functions that do not need to be 5107 ** used inside of triggers, view, CHECK constraints, or other elements of 5108 ** the database schema. This flags is especially recommended for SQL 5109 ** functions that have side effects or reveal internal application state. 5110 ** Without this flag, an attacker might be able to modify the schema of 5111 ** a database file to include invocations of the function with parameters 5112 ** chosen by the attacker, which the application will then execute when 5113 ** the database file is opened and read. 5114 ** </span> 5115 ** 5116 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5117 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5118 ** 5119 ** ^The sixth, seventh and eighth parameters passed to the three 5120 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5121 ** pointers to C-language functions that implement the SQL function or 5122 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5123 ** callback only; NULL pointers must be passed as the xStep and xFinal 5124 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5125 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5126 ** SQL function or aggregate, pass NULL pointers for all three function 5127 ** callbacks. 5128 ** 5129 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5130 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5131 ** C-language callbacks that implement the new function. xStep and xFinal 5132 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5133 ** which case a regular aggregate function is created, or must both be 5134 ** non-NULL, in which case the new function may be used as either an aggregate 5135 ** or aggregate window function. More details regarding the implementation 5136 ** of aggregate window functions are 5137 ** [user-defined window functions|available here]. 5138 ** 5139 ** ^(If the final parameter to sqlite3_create_function_v2() or 5140 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5141 ** the application data pointer. The destructor is invoked when the function 5142 ** is deleted, either by being overloaded or when the database connection 5143 ** closes.)^ ^The destructor is also invoked if the call to 5144 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5145 ** invoked, it is passed a single argument which is a copy of the application 5146 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5147 ** 5148 ** ^It is permitted to register multiple implementations of the same 5149 ** functions with the same name but with either differing numbers of 5150 ** arguments or differing preferred text encodings. ^SQLite will use 5151 ** the implementation that most closely matches the way in which the 5152 ** SQL function is used. ^A function implementation with a non-negative 5153 ** nArg parameter is a better match than a function implementation with 5154 ** a negative nArg. ^A function where the preferred text encoding 5155 ** matches the database encoding is a better 5156 ** match than a function where the encoding is different. 5157 ** ^A function where the encoding difference is between UTF16le and UTF16be 5158 ** is a closer match than a function where the encoding difference is 5159 ** between UTF8 and UTF16. 5160 ** 5161 ** ^Built-in functions may be overloaded by new application-defined functions. 5162 ** 5163 ** ^An application-defined function is permitted to call other 5164 ** SQLite interfaces. However, such calls must not 5165 ** close the database connection nor finalize or reset the prepared 5166 ** statement in which the function is running. 5167 */ 5168 SQLITE_API int sqlite3_create_function( 5169 sqlite3 *db, 5170 const char *zFunctionName, 5171 int nArg, 5172 int eTextRep, 5173 void *pApp, 5174 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5175 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5176 void (*xFinal)(sqlite3_context*) 5177 ); 5178 SQLITE_API int sqlite3_create_function16( 5179 sqlite3 *db, 5180 const void *zFunctionName, 5181 int nArg, 5182 int eTextRep, 5183 void *pApp, 5184 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5185 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5186 void (*xFinal)(sqlite3_context*) 5187 ); 5188 SQLITE_API int sqlite3_create_function_v2( 5189 sqlite3 *db, 5190 const char *zFunctionName, 5191 int nArg, 5192 int eTextRep, 5193 void *pApp, 5194 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5195 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5196 void (*xFinal)(sqlite3_context*), 5197 void(*xDestroy)(void*) 5198 ); 5199 SQLITE_API int sqlite3_create_window_function( 5200 sqlite3 *db, 5201 const char *zFunctionName, 5202 int nArg, 5203 int eTextRep, 5204 void *pApp, 5205 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5206 void (*xFinal)(sqlite3_context*), 5207 void (*xValue)(sqlite3_context*), 5208 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5209 void(*xDestroy)(void*) 5210 ); 5211 5212 /* 5213 ** CAPI3REF: Text Encodings 5214 ** 5215 ** These constant define integer codes that represent the various 5216 ** text encodings supported by SQLite. 5217 */ 5218 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5219 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5220 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5221 #define SQLITE_UTF16 4 /* Use native byte order */ 5222 #define SQLITE_ANY 5 /* Deprecated */ 5223 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5224 5225 /* 5226 ** CAPI3REF: Function Flags 5227 ** 5228 ** These constants may be ORed together with the 5229 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5230 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5231 ** [sqlite3_create_function_v2()]. 5232 ** 5233 ** <dl> 5234 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5235 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5236 ** the same output when the input parameters are the same. 5237 ** The [abs|abs() function] is deterministic, for example, but 5238 ** [randomblob|randomblob()] is not. Functions must 5239 ** be deterministic in order to be used in certain contexts such as 5240 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5241 ** SQLite might also optimize deterministic functions by factoring them 5242 ** out of inner loops. 5243 ** </dd> 5244 ** 5245 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5246 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5247 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5248 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5249 ** [expression indexes], [partial indexes], or [generated columns]. 5250 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5251 ** for all [application-defined SQL functions], and especially for functions 5252 ** that have side-effects or that could potentially leak sensitive 5253 ** information. 5254 ** </dd> 5255 ** 5256 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5257 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5258 ** to cause problems even if misused. An innocuous function should have 5259 ** no side effects and should not depend on any values other than its 5260 ** input parameters. The [abs|abs() function] is an example of an 5261 ** innocuous function. 5262 ** The [load_extension() SQL function] is not innocuous because of its 5263 ** side effects. 5264 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5265 ** exactly the same. The [random|random() function] is an example of a 5266 ** function that is innocuous but not deterministic. 5267 ** <p>Some heightened security settings 5268 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5269 ** disable the use of SQL functions inside views and triggers and in 5270 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5271 ** [expression indexes], [partial indexes], and [generated columns] unless 5272 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5273 ** are innocuous. Developers are advised to avoid using the 5274 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5275 ** function has been carefully audited and found to be free of potentially 5276 ** security-adverse side-effects and information-leaks. 5277 ** </dd> 5278 ** 5279 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5280 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5281 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5282 ** Specifying this flag makes no difference for scalar or aggregate user 5283 ** functions. However, if it is not specified for a user-defined window 5284 ** function, then any sub-types belonging to arguments passed to the window 5285 ** function may be discarded before the window function is called (i.e. 5286 ** sqlite3_value_subtype() will always return 0). 5287 ** </dd> 5288 ** </dl> 5289 */ 5290 #define SQLITE_DETERMINISTIC 0x000000800 5291 #define SQLITE_DIRECTONLY 0x000080000 5292 #define SQLITE_SUBTYPE 0x000100000 5293 #define SQLITE_INNOCUOUS 0x000200000 5294 5295 /* 5296 ** CAPI3REF: Deprecated Functions 5297 ** DEPRECATED 5298 ** 5299 ** These functions are [deprecated]. In order to maintain 5300 ** backwards compatibility with older code, these functions continue 5301 ** to be supported. However, new applications should avoid 5302 ** the use of these functions. To encourage programmers to avoid 5303 ** these functions, we will not explain what they do. 5304 */ 5305 #ifndef SQLITE_OMIT_DEPRECATED 5306 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5307 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5308 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5309 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5310 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5311 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5312 void*,sqlite3_int64); 5313 #endif 5314 5315 /* 5316 ** CAPI3REF: Obtaining SQL Values 5317 ** METHOD: sqlite3_value 5318 ** 5319 ** <b>Summary:</b> 5320 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5321 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5322 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5323 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5324 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5325 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5326 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5327 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5328 ** the native byteorder 5329 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5330 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5331 ** <tr><td> <td> <td> 5332 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5333 ** or a UTF-8 TEXT in bytes 5334 ** <tr><td><b>sqlite3_value_bytes16 </b> 5335 ** <td>→ <td>Size of UTF-16 5336 ** TEXT in bytes 5337 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5338 ** datatype of the value 5339 ** <tr><td><b>sqlite3_value_numeric_type </b> 5340 ** <td>→ <td>Best numeric datatype of the value 5341 ** <tr><td><b>sqlite3_value_nochange </b> 5342 ** <td>→ <td>True if the column is unchanged in an UPDATE 5343 ** against a virtual table. 5344 ** <tr><td><b>sqlite3_value_frombind </b> 5345 ** <td>→ <td>True if value originated from a [bound parameter] 5346 ** </table></blockquote> 5347 ** 5348 ** <b>Details:</b> 5349 ** 5350 ** These routines extract type, size, and content information from 5351 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5352 ** are used to pass parameter information into the functions that 5353 ** implement [application-defined SQL functions] and [virtual tables]. 5354 ** 5355 ** These routines work only with [protected sqlite3_value] objects. 5356 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5357 ** is not threadsafe. 5358 ** 5359 ** ^These routines work just like the corresponding [column access functions] 5360 ** except that these routines take a single [protected sqlite3_value] object 5361 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5362 ** 5363 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5364 ** in the native byte-order of the host machine. ^The 5365 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5366 ** extract UTF-16 strings as big-endian and little-endian respectively. 5367 ** 5368 ** ^If [sqlite3_value] object V was initialized 5369 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5370 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5371 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5372 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5373 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5374 ** 5375 ** ^(The sqlite3_value_type(V) interface returns the 5376 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5377 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5378 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5379 ** Other interfaces might change the datatype for an sqlite3_value object. 5380 ** For example, if the datatype is initially SQLITE_INTEGER and 5381 ** sqlite3_value_text(V) is called to extract a text value for that 5382 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5383 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5384 ** occurs is undefined and may change from one release of SQLite to the next. 5385 ** 5386 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5387 ** numeric affinity to the value. This means that an attempt is 5388 ** made to convert the value to an integer or floating point. If 5389 ** such a conversion is possible without loss of information (in other 5390 ** words, if the value is a string that looks like a number) 5391 ** then the conversion is performed. Otherwise no conversion occurs. 5392 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5393 ** 5394 ** ^Within the [xUpdate] method of a [virtual table], the 5395 ** sqlite3_value_nochange(X) interface returns true if and only if 5396 ** the column corresponding to X is unchanged by the UPDATE operation 5397 ** that the xUpdate method call was invoked to implement and if 5398 ** and the prior [xColumn] method call that was invoked to extracted 5399 ** the value for that column returned without setting a result (probably 5400 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5401 ** was unchanging). ^Within an [xUpdate] method, any value for which 5402 ** sqlite3_value_nochange(X) is true will in all other respects appear 5403 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5404 ** than within an [xUpdate] method call for an UPDATE statement, then 5405 ** the return value is arbitrary and meaningless. 5406 ** 5407 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5408 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5409 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5410 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5411 ** 5412 ** Please pay particular attention to the fact that the pointer returned 5413 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5414 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5415 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5416 ** or [sqlite3_value_text16()]. 5417 ** 5418 ** These routines must be called from the same thread as 5419 ** the SQL function that supplied the [sqlite3_value*] parameters. 5420 ** 5421 ** As long as the input parameter is correct, these routines can only 5422 ** fail if an out-of-memory error occurs during a format conversion. 5423 ** Only the following subset of interfaces are subject to out-of-memory 5424 ** errors: 5425 ** 5426 ** <ul> 5427 ** <li> sqlite3_value_blob() 5428 ** <li> sqlite3_value_text() 5429 ** <li> sqlite3_value_text16() 5430 ** <li> sqlite3_value_text16le() 5431 ** <li> sqlite3_value_text16be() 5432 ** <li> sqlite3_value_bytes() 5433 ** <li> sqlite3_value_bytes16() 5434 ** </ul> 5435 ** 5436 ** If an out-of-memory error occurs, then the return value from these 5437 ** routines is the same as if the column had contained an SQL NULL value. 5438 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5439 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5440 ** return value is obtained and before any 5441 ** other SQLite interface is called on the same [database connection]. 5442 */ 5443 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5444 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5445 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5446 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5447 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5448 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5449 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5450 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5451 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5452 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5453 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5454 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5455 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5456 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5457 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5458 5459 /* 5460 ** CAPI3REF: Finding The Subtype Of SQL Values 5461 ** METHOD: sqlite3_value 5462 ** 5463 ** The sqlite3_value_subtype(V) function returns the subtype for 5464 ** an [application-defined SQL function] argument V. The subtype 5465 ** information can be used to pass a limited amount of context from 5466 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5467 ** routine to set the subtype for the return value of an SQL function. 5468 */ 5469 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5470 5471 /* 5472 ** CAPI3REF: Copy And Free SQL Values 5473 ** METHOD: sqlite3_value 5474 ** 5475 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5476 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5477 ** is a [protected sqlite3_value] object even if the input is not. 5478 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5479 ** memory allocation fails. 5480 ** 5481 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5482 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5483 ** then sqlite3_value_free(V) is a harmless no-op. 5484 */ 5485 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5486 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5487 5488 /* 5489 ** CAPI3REF: Obtain Aggregate Function Context 5490 ** METHOD: sqlite3_context 5491 ** 5492 ** Implementations of aggregate SQL functions use this 5493 ** routine to allocate memory for storing their state. 5494 ** 5495 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5496 ** for a particular aggregate function, SQLite allocates 5497 ** N bytes of memory, zeroes out that memory, and returns a pointer 5498 ** to the new memory. ^On second and subsequent calls to 5499 ** sqlite3_aggregate_context() for the same aggregate function instance, 5500 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5501 ** called once for each invocation of the xStep callback and then one 5502 ** last time when the xFinal callback is invoked. ^(When no rows match 5503 ** an aggregate query, the xStep() callback of the aggregate function 5504 ** implementation is never called and xFinal() is called exactly once. 5505 ** In those cases, sqlite3_aggregate_context() might be called for the 5506 ** first time from within xFinal().)^ 5507 ** 5508 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5509 ** when first called if N is less than or equal to zero or if a memory 5510 ** allocate error occurs. 5511 ** 5512 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5513 ** determined by the N parameter on first successful call. Changing the 5514 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5515 ** the same aggregate function instance will not resize the memory 5516 ** allocation.)^ Within the xFinal callback, it is customary to set 5517 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5518 ** pointless memory allocations occur. 5519 ** 5520 ** ^SQLite automatically frees the memory allocated by 5521 ** sqlite3_aggregate_context() when the aggregate query concludes. 5522 ** 5523 ** The first parameter must be a copy of the 5524 ** [sqlite3_context | SQL function context] that is the first parameter 5525 ** to the xStep or xFinal callback routine that implements the aggregate 5526 ** function. 5527 ** 5528 ** This routine must be called from the same thread in which 5529 ** the aggregate SQL function is running. 5530 */ 5531 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5532 5533 /* 5534 ** CAPI3REF: User Data For Functions 5535 ** METHOD: sqlite3_context 5536 ** 5537 ** ^The sqlite3_user_data() interface returns a copy of 5538 ** the pointer that was the pUserData parameter (the 5th parameter) 5539 ** of the [sqlite3_create_function()] 5540 ** and [sqlite3_create_function16()] routines that originally 5541 ** registered the application defined function. 5542 ** 5543 ** This routine must be called from the same thread in which 5544 ** the application-defined function is running. 5545 */ 5546 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5547 5548 /* 5549 ** CAPI3REF: Database Connection For Functions 5550 ** METHOD: sqlite3_context 5551 ** 5552 ** ^The sqlite3_context_db_handle() interface returns a copy of 5553 ** the pointer to the [database connection] (the 1st parameter) 5554 ** of the [sqlite3_create_function()] 5555 ** and [sqlite3_create_function16()] routines that originally 5556 ** registered the application defined function. 5557 */ 5558 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5559 5560 /* 5561 ** CAPI3REF: Function Auxiliary Data 5562 ** METHOD: sqlite3_context 5563 ** 5564 ** These functions may be used by (non-aggregate) SQL functions to 5565 ** associate metadata with argument values. If the same value is passed to 5566 ** multiple invocations of the same SQL function during query execution, under 5567 ** some circumstances the associated metadata may be preserved. An example 5568 ** of where this might be useful is in a regular-expression matching 5569 ** function. The compiled version of the regular expression can be stored as 5570 ** metadata associated with the pattern string. 5571 ** Then as long as the pattern string remains the same, 5572 ** the compiled regular expression can be reused on multiple 5573 ** invocations of the same function. 5574 ** 5575 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5576 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5577 ** value to the application-defined function. ^N is zero for the left-most 5578 ** function argument. ^If there is no metadata 5579 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5580 ** returns a NULL pointer. 5581 ** 5582 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5583 ** argument of the application-defined function. ^Subsequent 5584 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5585 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5586 ** NULL if the metadata has been discarded. 5587 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5588 ** SQLite will invoke the destructor function X with parameter P exactly 5589 ** once, when the metadata is discarded. 5590 ** SQLite is free to discard the metadata at any time, including: <ul> 5591 ** <li> ^(when the corresponding function parameter changes)^, or 5592 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5593 ** SQL statement)^, or 5594 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5595 ** parameter)^, or 5596 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5597 ** allocation error occurs.)^ </ul> 5598 ** 5599 ** Note the last bullet in particular. The destructor X in 5600 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5601 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5602 ** should be called near the end of the function implementation and the 5603 ** function implementation should not make any use of P after 5604 ** sqlite3_set_auxdata() has been called. 5605 ** 5606 ** ^(In practice, metadata is preserved between function calls for 5607 ** function parameters that are compile-time constants, including literal 5608 ** values and [parameters] and expressions composed from the same.)^ 5609 ** 5610 ** The value of the N parameter to these interfaces should be non-negative. 5611 ** Future enhancements may make use of negative N values to define new 5612 ** kinds of function caching behavior. 5613 ** 5614 ** These routines must be called from the same thread in which 5615 ** the SQL function is running. 5616 */ 5617 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5618 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5619 5620 5621 /* 5622 ** CAPI3REF: Constants Defining Special Destructor Behavior 5623 ** 5624 ** These are special values for the destructor that is passed in as the 5625 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5626 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5627 ** and will never change. It does not need to be destroyed. ^The 5628 ** SQLITE_TRANSIENT value means that the content will likely change in 5629 ** the near future and that SQLite should make its own private copy of 5630 ** the content before returning. 5631 ** 5632 ** The typedef is necessary to work around problems in certain 5633 ** C++ compilers. 5634 */ 5635 typedef void (*sqlite3_destructor_type)(void*); 5636 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5637 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5638 5639 /* 5640 ** CAPI3REF: Setting The Result Of An SQL Function 5641 ** METHOD: sqlite3_context 5642 ** 5643 ** These routines are used by the xFunc or xFinal callbacks that 5644 ** implement SQL functions and aggregates. See 5645 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5646 ** for additional information. 5647 ** 5648 ** These functions work very much like the [parameter binding] family of 5649 ** functions used to bind values to host parameters in prepared statements. 5650 ** Refer to the [SQL parameter] documentation for additional information. 5651 ** 5652 ** ^The sqlite3_result_blob() interface sets the result from 5653 ** an application-defined function to be the BLOB whose content is pointed 5654 ** to by the second parameter and which is N bytes long where N is the 5655 ** third parameter. 5656 ** 5657 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5658 ** interfaces set the result of the application-defined function to be 5659 ** a BLOB containing all zero bytes and N bytes in size. 5660 ** 5661 ** ^The sqlite3_result_double() interface sets the result from 5662 ** an application-defined function to be a floating point value specified 5663 ** by its 2nd argument. 5664 ** 5665 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5666 ** cause the implemented SQL function to throw an exception. 5667 ** ^SQLite uses the string pointed to by the 5668 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5669 ** as the text of an error message. ^SQLite interprets the error 5670 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5671 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5672 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5673 ** ^If the third parameter to sqlite3_result_error() 5674 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5675 ** message all text up through the first zero character. 5676 ** ^If the third parameter to sqlite3_result_error() or 5677 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5678 ** bytes (not characters) from the 2nd parameter as the error message. 5679 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5680 ** routines make a private copy of the error message text before 5681 ** they return. Hence, the calling function can deallocate or 5682 ** modify the text after they return without harm. 5683 ** ^The sqlite3_result_error_code() function changes the error code 5684 ** returned by SQLite as a result of an error in a function. ^By default, 5685 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5686 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5687 ** 5688 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5689 ** error indicating that a string or BLOB is too long to represent. 5690 ** 5691 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5692 ** error indicating that a memory allocation failed. 5693 ** 5694 ** ^The sqlite3_result_int() interface sets the return value 5695 ** of the application-defined function to be the 32-bit signed integer 5696 ** value given in the 2nd argument. 5697 ** ^The sqlite3_result_int64() interface sets the return value 5698 ** of the application-defined function to be the 64-bit signed integer 5699 ** value given in the 2nd argument. 5700 ** 5701 ** ^The sqlite3_result_null() interface sets the return value 5702 ** of the application-defined function to be NULL. 5703 ** 5704 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5705 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5706 ** set the return value of the application-defined function to be 5707 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5708 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5709 ** ^The sqlite3_result_text64() interface sets the return value of an 5710 ** application-defined function to be a text string in an encoding 5711 ** specified by the fifth (and last) parameter, which must be one 5712 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5713 ** ^SQLite takes the text result from the application from 5714 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5715 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5716 ** is negative, then SQLite takes result text from the 2nd parameter 5717 ** through the first zero character. 5718 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5719 ** is non-negative, then as many bytes (not characters) of the text 5720 ** pointed to by the 2nd parameter are taken as the application-defined 5721 ** function result. If the 3rd parameter is non-negative, then it 5722 ** must be the byte offset into the string where the NUL terminator would 5723 ** appear if the string where NUL terminated. If any NUL characters occur 5724 ** in the string at a byte offset that is less than the value of the 3rd 5725 ** parameter, then the resulting string will contain embedded NULs and the 5726 ** result of expressions operating on strings with embedded NULs is undefined. 5727 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5728 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5729 ** function as the destructor on the text or BLOB result when it has 5730 ** finished using that result. 5731 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5732 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5733 ** assumes that the text or BLOB result is in constant space and does not 5734 ** copy the content of the parameter nor call a destructor on the content 5735 ** when it has finished using that result. 5736 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5737 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5738 ** then SQLite makes a copy of the result into space obtained 5739 ** from [sqlite3_malloc()] before it returns. 5740 ** 5741 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5742 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5743 ** when the encoding is not UTF8, if the input UTF16 begins with a 5744 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5745 ** string and the rest of the string is interpreted according to the 5746 ** byte-order specified by the BOM. ^The byte-order specified by 5747 ** the BOM at the beginning of the text overrides the byte-order 5748 ** specified by the interface procedure. ^So, for example, if 5749 ** sqlite3_result_text16le() is invoked with text that begins 5750 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5751 ** first two bytes of input are skipped and the remaining input 5752 ** is interpreted as UTF16BE text. 5753 ** 5754 ** ^For UTF16 input text to the sqlite3_result_text16(), 5755 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5756 ** sqlite3_result_text64() routines, if the text contains invalid 5757 ** UTF16 characters, the invalid characters might be converted 5758 ** into the unicode replacement character, U+FFFD. 5759 ** 5760 ** ^The sqlite3_result_value() interface sets the result of 5761 ** the application-defined function to be a copy of the 5762 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5763 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5764 ** so that the [sqlite3_value] specified in the parameter may change or 5765 ** be deallocated after sqlite3_result_value() returns without harm. 5766 ** ^A [protected sqlite3_value] object may always be used where an 5767 ** [unprotected sqlite3_value] object is required, so either 5768 ** kind of [sqlite3_value] object can be used with this interface. 5769 ** 5770 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5771 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5772 ** also associates the host-language pointer P or type T with that 5773 ** NULL value such that the pointer can be retrieved within an 5774 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5775 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5776 ** for the P parameter. ^SQLite invokes D with P as its only argument 5777 ** when SQLite is finished with P. The T parameter should be a static 5778 ** string and preferably a string literal. The sqlite3_result_pointer() 5779 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5780 ** 5781 ** If these routines are called from within the different thread 5782 ** than the one containing the application-defined function that received 5783 ** the [sqlite3_context] pointer, the results are undefined. 5784 */ 5785 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5786 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5787 sqlite3_uint64,void(*)(void*)); 5788 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5789 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5790 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5791 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5792 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5793 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5794 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5795 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5796 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5797 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5798 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5799 void(*)(void*), unsigned char encoding); 5800 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5801 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5802 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5803 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5804 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5805 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5806 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5807 5808 5809 /* 5810 ** CAPI3REF: Setting The Subtype Of An SQL Function 5811 ** METHOD: sqlite3_context 5812 ** 5813 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5814 ** the result from the [application-defined SQL function] with 5815 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5816 ** of the subtype T are preserved in current versions of SQLite; 5817 ** higher order bits are discarded. 5818 ** The number of subtype bytes preserved by SQLite might increase 5819 ** in future releases of SQLite. 5820 */ 5821 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5822 5823 /* 5824 ** CAPI3REF: Define New Collating Sequences 5825 ** METHOD: sqlite3 5826 ** 5827 ** ^These functions add, remove, or modify a [collation] associated 5828 ** with the [database connection] specified as the first argument. 5829 ** 5830 ** ^The name of the collation is a UTF-8 string 5831 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5832 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5833 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5834 ** considered to be the same name. 5835 ** 5836 ** ^(The third argument (eTextRep) must be one of the constants: 5837 ** <ul> 5838 ** <li> [SQLITE_UTF8], 5839 ** <li> [SQLITE_UTF16LE], 5840 ** <li> [SQLITE_UTF16BE], 5841 ** <li> [SQLITE_UTF16], or 5842 ** <li> [SQLITE_UTF16_ALIGNED]. 5843 ** </ul>)^ 5844 ** ^The eTextRep argument determines the encoding of strings passed 5845 ** to the collating function callback, xCompare. 5846 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5847 ** force strings to be UTF16 with native byte order. 5848 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5849 ** on an even byte address. 5850 ** 5851 ** ^The fourth argument, pArg, is an application data pointer that is passed 5852 ** through as the first argument to the collating function callback. 5853 ** 5854 ** ^The fifth argument, xCompare, is a pointer to the collating function. 5855 ** ^Multiple collating functions can be registered using the same name but 5856 ** with different eTextRep parameters and SQLite will use whichever 5857 ** function requires the least amount of data transformation. 5858 ** ^If the xCompare argument is NULL then the collating function is 5859 ** deleted. ^When all collating functions having the same name are deleted, 5860 ** that collation is no longer usable. 5861 ** 5862 ** ^The collating function callback is invoked with a copy of the pArg 5863 ** application data pointer and with two strings in the encoding specified 5864 ** by the eTextRep argument. The two integer parameters to the collating 5865 ** function callback are the length of the two strings, in bytes. The collating 5866 ** function must return an integer that is negative, zero, or positive 5867 ** if the first string is less than, equal to, or greater than the second, 5868 ** respectively. A collating function must always return the same answer 5869 ** given the same inputs. If two or more collating functions are registered 5870 ** to the same collation name (using different eTextRep values) then all 5871 ** must give an equivalent answer when invoked with equivalent strings. 5872 ** The collating function must obey the following properties for all 5873 ** strings A, B, and C: 5874 ** 5875 ** <ol> 5876 ** <li> If A==B then B==A. 5877 ** <li> If A==B and B==C then A==C. 5878 ** <li> If A<B THEN B>A. 5879 ** <li> If A<B and B<C then A<C. 5880 ** </ol> 5881 ** 5882 ** If a collating function fails any of the above constraints and that 5883 ** collating function is registered and used, then the behavior of SQLite 5884 ** is undefined. 5885 ** 5886 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5887 ** with the addition that the xDestroy callback is invoked on pArg when 5888 ** the collating function is deleted. 5889 ** ^Collating functions are deleted when they are overridden by later 5890 ** calls to the collation creation functions or when the 5891 ** [database connection] is closed using [sqlite3_close()]. 5892 ** 5893 ** ^The xDestroy callback is <u>not</u> called if the 5894 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5895 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5896 ** check the return code and dispose of the application data pointer 5897 ** themselves rather than expecting SQLite to deal with it for them. 5898 ** This is different from every other SQLite interface. The inconsistency 5899 ** is unfortunate but cannot be changed without breaking backwards 5900 ** compatibility. 5901 ** 5902 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5903 */ 5904 SQLITE_API int sqlite3_create_collation( 5905 sqlite3*, 5906 const char *zName, 5907 int eTextRep, 5908 void *pArg, 5909 int(*xCompare)(void*,int,const void*,int,const void*) 5910 ); 5911 SQLITE_API int sqlite3_create_collation_v2( 5912 sqlite3*, 5913 const char *zName, 5914 int eTextRep, 5915 void *pArg, 5916 int(*xCompare)(void*,int,const void*,int,const void*), 5917 void(*xDestroy)(void*) 5918 ); 5919 SQLITE_API int sqlite3_create_collation16( 5920 sqlite3*, 5921 const void *zName, 5922 int eTextRep, 5923 void *pArg, 5924 int(*xCompare)(void*,int,const void*,int,const void*) 5925 ); 5926 5927 /* 5928 ** CAPI3REF: Collation Needed Callbacks 5929 ** METHOD: sqlite3 5930 ** 5931 ** ^To avoid having to register all collation sequences before a database 5932 ** can be used, a single callback function may be registered with the 5933 ** [database connection] to be invoked whenever an undefined collation 5934 ** sequence is required. 5935 ** 5936 ** ^If the function is registered using the sqlite3_collation_needed() API, 5937 ** then it is passed the names of undefined collation sequences as strings 5938 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5939 ** the names are passed as UTF-16 in machine native byte order. 5940 ** ^A call to either function replaces the existing collation-needed callback. 5941 ** 5942 ** ^(When the callback is invoked, the first argument passed is a copy 5943 ** of the second argument to sqlite3_collation_needed() or 5944 ** sqlite3_collation_needed16(). The second argument is the database 5945 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5946 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5947 ** sequence function required. The fourth parameter is the name of the 5948 ** required collation sequence.)^ 5949 ** 5950 ** The callback function should register the desired collation using 5951 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5952 ** [sqlite3_create_collation_v2()]. 5953 */ 5954 SQLITE_API int sqlite3_collation_needed( 5955 sqlite3*, 5956 void*, 5957 void(*)(void*,sqlite3*,int eTextRep,const char*) 5958 ); 5959 SQLITE_API int sqlite3_collation_needed16( 5960 sqlite3*, 5961 void*, 5962 void(*)(void*,sqlite3*,int eTextRep,const void*) 5963 ); 5964 5965 #ifdef SQLITE_ENABLE_CEROD 5966 /* 5967 ** Specify the activation key for a CEROD database. Unless 5968 ** activated, none of the CEROD routines will work. 5969 */ 5970 SQLITE_API void sqlite3_activate_cerod( 5971 const char *zPassPhrase /* Activation phrase */ 5972 ); 5973 #endif 5974 5975 /* 5976 ** CAPI3REF: Suspend Execution For A Short Time 5977 ** 5978 ** The sqlite3_sleep() function causes the current thread to suspend execution 5979 ** for at least a number of milliseconds specified in its parameter. 5980 ** 5981 ** If the operating system does not support sleep requests with 5982 ** millisecond time resolution, then the time will be rounded up to 5983 ** the nearest second. The number of milliseconds of sleep actually 5984 ** requested from the operating system is returned. 5985 ** 5986 ** ^SQLite implements this interface by calling the xSleep() 5987 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5988 ** of the default VFS is not implemented correctly, or not implemented at 5989 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5990 ** in the previous paragraphs. 5991 */ 5992 SQLITE_API int sqlite3_sleep(int); 5993 5994 /* 5995 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5996 ** 5997 ** ^(If this global variable is made to point to a string which is 5998 ** the name of a folder (a.k.a. directory), then all temporary files 5999 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6000 ** will be placed in that directory.)^ ^If this variable 6001 ** is a NULL pointer, then SQLite performs a search for an appropriate 6002 ** temporary file directory. 6003 ** 6004 ** Applications are strongly discouraged from using this global variable. 6005 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6006 ** But for all other platforms, it is highly recommended that applications 6007 ** neither read nor write this variable. This global variable is a relic 6008 ** that exists for backwards compatibility of legacy applications and should 6009 ** be avoided in new projects. 6010 ** 6011 ** It is not safe to read or modify this variable in more than one 6012 ** thread at a time. It is not safe to read or modify this variable 6013 ** if a [database connection] is being used at the same time in a separate 6014 ** thread. 6015 ** It is intended that this variable be set once 6016 ** as part of process initialization and before any SQLite interface 6017 ** routines have been called and that this variable remain unchanged 6018 ** thereafter. 6019 ** 6020 ** ^The [temp_store_directory pragma] may modify this variable and cause 6021 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6022 ** the [temp_store_directory pragma] always assumes that any string 6023 ** that this variable points to is held in memory obtained from 6024 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6025 ** using [sqlite3_free]. 6026 ** Hence, if this variable is modified directly, either it should be 6027 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6028 ** or else the use of the [temp_store_directory pragma] should be avoided. 6029 ** Except when requested by the [temp_store_directory pragma], SQLite 6030 ** does not free the memory that sqlite3_temp_directory points to. If 6031 ** the application wants that memory to be freed, it must do 6032 ** so itself, taking care to only do so after all [database connection] 6033 ** objects have been destroyed. 6034 ** 6035 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6036 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6037 ** features that require the use of temporary files may fail. Here is an 6038 ** example of how to do this using C++ with the Windows Runtime: 6039 ** 6040 ** <blockquote><pre> 6041 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6042 ** TemporaryFolder->Path->Data(); 6043 ** char zPathBuf[MAX_PATH + 1]; 6044 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6045 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6046 ** NULL, NULL); 6047 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6048 ** </pre></blockquote> 6049 */ 6050 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6051 6052 /* 6053 ** CAPI3REF: Name Of The Folder Holding Database Files 6054 ** 6055 ** ^(If this global variable is made to point to a string which is 6056 ** the name of a folder (a.k.a. directory), then all database files 6057 ** specified with a relative pathname and created or accessed by 6058 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6059 ** to be relative to that directory.)^ ^If this variable is a NULL 6060 ** pointer, then SQLite assumes that all database files specified 6061 ** with a relative pathname are relative to the current directory 6062 ** for the process. Only the windows VFS makes use of this global 6063 ** variable; it is ignored by the unix VFS. 6064 ** 6065 ** Changing the value of this variable while a database connection is 6066 ** open can result in a corrupt database. 6067 ** 6068 ** It is not safe to read or modify this variable in more than one 6069 ** thread at a time. It is not safe to read or modify this variable 6070 ** if a [database connection] is being used at the same time in a separate 6071 ** thread. 6072 ** It is intended that this variable be set once 6073 ** as part of process initialization and before any SQLite interface 6074 ** routines have been called and that this variable remain unchanged 6075 ** thereafter. 6076 ** 6077 ** ^The [data_store_directory pragma] may modify this variable and cause 6078 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6079 ** the [data_store_directory pragma] always assumes that any string 6080 ** that this variable points to is held in memory obtained from 6081 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6082 ** using [sqlite3_free]. 6083 ** Hence, if this variable is modified directly, either it should be 6084 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6085 ** or else the use of the [data_store_directory pragma] should be avoided. 6086 */ 6087 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6088 6089 /* 6090 ** CAPI3REF: Win32 Specific Interface 6091 ** 6092 ** These interfaces are available only on Windows. The 6093 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6094 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6095 ** zValue, depending on the value of the type parameter. The zValue parameter 6096 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6097 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6098 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6099 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6100 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6101 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6102 ** the current directory on the sub-platforms of Win32 where that concept is 6103 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6104 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6105 ** sqlite3_win32_set_directory interface except the string parameter must be 6106 ** UTF-8 or UTF-16, respectively. 6107 */ 6108 SQLITE_API int sqlite3_win32_set_directory( 6109 unsigned long type, /* Identifier for directory being set or reset */ 6110 void *zValue /* New value for directory being set or reset */ 6111 ); 6112 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6113 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6114 6115 /* 6116 ** CAPI3REF: Win32 Directory Types 6117 ** 6118 ** These macros are only available on Windows. They define the allowed values 6119 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6120 */ 6121 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6122 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6123 6124 /* 6125 ** CAPI3REF: Test For Auto-Commit Mode 6126 ** KEYWORDS: {autocommit mode} 6127 ** METHOD: sqlite3 6128 ** 6129 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6130 ** zero if the given database connection is or is not in autocommit mode, 6131 ** respectively. ^Autocommit mode is on by default. 6132 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6133 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6134 ** 6135 ** If certain kinds of errors occur on a statement within a multi-statement 6136 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6137 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6138 ** transaction might be rolled back automatically. The only way to 6139 ** find out whether SQLite automatically rolled back the transaction after 6140 ** an error is to use this function. 6141 ** 6142 ** If another thread changes the autocommit status of the database 6143 ** connection while this routine is running, then the return value 6144 ** is undefined. 6145 */ 6146 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6147 6148 /* 6149 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6150 ** METHOD: sqlite3_stmt 6151 ** 6152 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6153 ** to which a [prepared statement] belongs. ^The [database connection] 6154 ** returned by sqlite3_db_handle is the same [database connection] 6155 ** that was the first argument 6156 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6157 ** create the statement in the first place. 6158 */ 6159 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6160 6161 /* 6162 ** CAPI3REF: Return The Filename For A Database Connection 6163 ** METHOD: sqlite3 6164 ** 6165 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6166 ** associated with database N of connection D. 6167 ** ^If there is no attached database N on the database 6168 ** connection D, or if database N is a temporary or in-memory database, then 6169 ** this function will return either a NULL pointer or an empty string. 6170 ** 6171 ** ^The string value returned by this routine is owned and managed by 6172 ** the database connection. ^The value will be valid until the database N 6173 ** is [DETACH]-ed or until the database connection closes. 6174 ** 6175 ** ^The filename returned by this function is the output of the 6176 ** xFullPathname method of the [VFS]. ^In other words, the filename 6177 ** will be an absolute pathname, even if the filename used 6178 ** to open the database originally was a URI or relative pathname. 6179 ** 6180 ** If the filename pointer returned by this routine is not NULL, then it 6181 ** can be used as the filename input parameter to these routines: 6182 ** <ul> 6183 ** <li> [sqlite3_uri_parameter()] 6184 ** <li> [sqlite3_uri_boolean()] 6185 ** <li> [sqlite3_uri_int64()] 6186 ** <li> [sqlite3_filename_database()] 6187 ** <li> [sqlite3_filename_journal()] 6188 ** <li> [sqlite3_filename_wal()] 6189 ** </ul> 6190 */ 6191 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6192 6193 /* 6194 ** CAPI3REF: Determine if a database is read-only 6195 ** METHOD: sqlite3 6196 ** 6197 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6198 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6199 ** the name of a database on connection D. 6200 */ 6201 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6202 6203 /* 6204 ** CAPI3REF: Determine the transaction state of a database 6205 ** METHOD: sqlite3 6206 ** 6207 ** ^The sqlite3_txn_state(D,S) interface returns the current 6208 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6209 ** then the highest transaction state of any schema on database connection D 6210 ** is returned. Transaction states are (in order of lowest to highest): 6211 ** <ol> 6212 ** <li value="0"> SQLITE_TXN_NONE 6213 ** <li value="1"> SQLITE_TXN_READ 6214 ** <li value="2"> SQLITE_TXN_WRITE 6215 ** </ol> 6216 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6217 ** a valid schema, then -1 is returned. 6218 */ 6219 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6220 6221 /* 6222 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6223 ** KEYWORDS: {transaction state} 6224 ** 6225 ** These constants define the current transaction state of a database file. 6226 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6227 ** constants in order to describe the transaction state of schema S 6228 ** in [database connection] D. 6229 ** 6230 ** <dl> 6231 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6232 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6233 ** pending.</dd> 6234 ** 6235 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6236 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6237 ** in a read transaction. Content has been read from the database file 6238 ** but nothing in the database file has changed. The transaction state 6239 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6240 ** no other conflicting concurrent write transactions. The transaction 6241 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6242 ** [COMMIT].</dd> 6243 ** 6244 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6245 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6246 ** in a write transaction. Content has been written to the database file 6247 ** but has not yet committed. The transaction state will change to 6248 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6249 */ 6250 #define SQLITE_TXN_NONE 0 6251 #define SQLITE_TXN_READ 1 6252 #define SQLITE_TXN_WRITE 2 6253 6254 /* 6255 ** CAPI3REF: Find the next prepared statement 6256 ** METHOD: sqlite3 6257 ** 6258 ** ^This interface returns a pointer to the next [prepared statement] after 6259 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6260 ** then this interface returns a pointer to the first prepared statement 6261 ** associated with the database connection pDb. ^If no prepared statement 6262 ** satisfies the conditions of this routine, it returns NULL. 6263 ** 6264 ** The [database connection] pointer D in a call to 6265 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6266 ** connection and in particular must not be a NULL pointer. 6267 */ 6268 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6269 6270 /* 6271 ** CAPI3REF: Commit And Rollback Notification Callbacks 6272 ** METHOD: sqlite3 6273 ** 6274 ** ^The sqlite3_commit_hook() interface registers a callback 6275 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6276 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6277 ** for the same database connection is overridden. 6278 ** ^The sqlite3_rollback_hook() interface registers a callback 6279 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6280 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6281 ** for the same database connection is overridden. 6282 ** ^The pArg argument is passed through to the callback. 6283 ** ^If the callback on a commit hook function returns non-zero, 6284 ** then the commit is converted into a rollback. 6285 ** 6286 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6287 ** return the P argument from the previous call of the same function 6288 ** on the same [database connection] D, or NULL for 6289 ** the first call for each function on D. 6290 ** 6291 ** The commit and rollback hook callbacks are not reentrant. 6292 ** The callback implementation must not do anything that will modify 6293 ** the database connection that invoked the callback. Any actions 6294 ** to modify the database connection must be deferred until after the 6295 ** completion of the [sqlite3_step()] call that triggered the commit 6296 ** or rollback hook in the first place. 6297 ** Note that running any other SQL statements, including SELECT statements, 6298 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6299 ** the database connections for the meaning of "modify" in this paragraph. 6300 ** 6301 ** ^Registering a NULL function disables the callback. 6302 ** 6303 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6304 ** operation is allowed to continue normally. ^If the commit hook 6305 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6306 ** ^The rollback hook is invoked on a rollback that results from a commit 6307 ** hook returning non-zero, just as it would be with any other rollback. 6308 ** 6309 ** ^For the purposes of this API, a transaction is said to have been 6310 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6311 ** an error or constraint causes an implicit rollback to occur. 6312 ** ^The rollback callback is not invoked if a transaction is 6313 ** automatically rolled back because the database connection is closed. 6314 ** 6315 ** See also the [sqlite3_update_hook()] interface. 6316 */ 6317 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6318 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6319 6320 /* 6321 ** CAPI3REF: Data Change Notification Callbacks 6322 ** METHOD: sqlite3 6323 ** 6324 ** ^The sqlite3_update_hook() interface registers a callback function 6325 ** with the [database connection] identified by the first argument 6326 ** to be invoked whenever a row is updated, inserted or deleted in 6327 ** a [rowid table]. 6328 ** ^Any callback set by a previous call to this function 6329 ** for the same database connection is overridden. 6330 ** 6331 ** ^The second argument is a pointer to the function to invoke when a 6332 ** row is updated, inserted or deleted in a rowid table. 6333 ** ^The first argument to the callback is a copy of the third argument 6334 ** to sqlite3_update_hook(). 6335 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6336 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6337 ** to be invoked. 6338 ** ^The third and fourth arguments to the callback contain pointers to the 6339 ** database and table name containing the affected row. 6340 ** ^The final callback parameter is the [rowid] of the row. 6341 ** ^In the case of an update, this is the [rowid] after the update takes place. 6342 ** 6343 ** ^(The update hook is not invoked when internal system tables are 6344 ** modified (i.e. sqlite_sequence).)^ 6345 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6346 ** 6347 ** ^In the current implementation, the update hook 6348 ** is not invoked when conflicting rows are deleted because of an 6349 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6350 ** invoked when rows are deleted using the [truncate optimization]. 6351 ** The exceptions defined in this paragraph might change in a future 6352 ** release of SQLite. 6353 ** 6354 ** The update hook implementation must not do anything that will modify 6355 ** the database connection that invoked the update hook. Any actions 6356 ** to modify the database connection must be deferred until after the 6357 ** completion of the [sqlite3_step()] call that triggered the update hook. 6358 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6359 ** database connections for the meaning of "modify" in this paragraph. 6360 ** 6361 ** ^The sqlite3_update_hook(D,C,P) function 6362 ** returns the P argument from the previous call 6363 ** on the same [database connection] D, or NULL for 6364 ** the first call on D. 6365 ** 6366 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6367 ** and [sqlite3_preupdate_hook()] interfaces. 6368 */ 6369 SQLITE_API void *sqlite3_update_hook( 6370 sqlite3*, 6371 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6372 void* 6373 ); 6374 6375 /* 6376 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6377 ** 6378 ** ^(This routine enables or disables the sharing of the database cache 6379 ** and schema data structures between [database connection | connections] 6380 ** to the same database. Sharing is enabled if the argument is true 6381 ** and disabled if the argument is false.)^ 6382 ** 6383 ** ^Cache sharing is enabled and disabled for an entire process. 6384 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6385 ** In prior versions of SQLite, 6386 ** sharing was enabled or disabled for each thread separately. 6387 ** 6388 ** ^(The cache sharing mode set by this interface effects all subsequent 6389 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6390 ** Existing database connections continue to use the sharing mode 6391 ** that was in effect at the time they were opened.)^ 6392 ** 6393 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6394 ** successfully. An [error code] is returned otherwise.)^ 6395 ** 6396 ** ^Shared cache is disabled by default. It is recommended that it stay 6397 ** that way. In other words, do not use this routine. This interface 6398 ** continues to be provided for historical compatibility, but its use is 6399 ** discouraged. Any use of shared cache is discouraged. If shared cache 6400 ** must be used, it is recommended that shared cache only be enabled for 6401 ** individual database connections using the [sqlite3_open_v2()] interface 6402 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6403 ** 6404 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6405 ** and will always return SQLITE_MISUSE. On those systems, 6406 ** shared cache mode should be enabled per-database connection via 6407 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6408 ** 6409 ** This interface is threadsafe on processors where writing a 6410 ** 32-bit integer is atomic. 6411 ** 6412 ** See Also: [SQLite Shared-Cache Mode] 6413 */ 6414 SQLITE_API int sqlite3_enable_shared_cache(int); 6415 6416 /* 6417 ** CAPI3REF: Attempt To Free Heap Memory 6418 ** 6419 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6420 ** of heap memory by deallocating non-essential memory allocations 6421 ** held by the database library. Memory used to cache database 6422 ** pages to improve performance is an example of non-essential memory. 6423 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6424 ** which might be more or less than the amount requested. 6425 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6426 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6427 ** 6428 ** See also: [sqlite3_db_release_memory()] 6429 */ 6430 SQLITE_API int sqlite3_release_memory(int); 6431 6432 /* 6433 ** CAPI3REF: Free Memory Used By A Database Connection 6434 ** METHOD: sqlite3 6435 ** 6436 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6437 ** memory as possible from database connection D. Unlike the 6438 ** [sqlite3_release_memory()] interface, this interface is in effect even 6439 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6440 ** omitted. 6441 ** 6442 ** See also: [sqlite3_release_memory()] 6443 */ 6444 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6445 6446 /* 6447 ** CAPI3REF: Impose A Limit On Heap Size 6448 ** 6449 ** These interfaces impose limits on the amount of heap memory that will be 6450 ** by all database connections within a single process. 6451 ** 6452 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6453 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6454 ** ^SQLite strives to keep heap memory utilization below the soft heap 6455 ** limit by reducing the number of pages held in the page cache 6456 ** as heap memory usages approaches the limit. 6457 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6458 ** below the limit, it will exceed the limit rather than generate 6459 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6460 ** is advisory only. 6461 ** 6462 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6463 ** N bytes on the amount of memory that will be allocated. ^The 6464 ** sqlite3_hard_heap_limit64(N) interface is similar to 6465 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6466 ** when the hard heap limit is reached. 6467 ** 6468 ** ^The return value from both sqlite3_soft_heap_limit64() and 6469 ** sqlite3_hard_heap_limit64() is the size of 6470 ** the heap limit prior to the call, or negative in the case of an 6471 ** error. ^If the argument N is negative 6472 ** then no change is made to the heap limit. Hence, the current 6473 ** size of heap limits can be determined by invoking 6474 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6475 ** 6476 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6477 ** 6478 ** ^The soft heap limit may not be greater than the hard heap limit. 6479 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6480 ** is invoked with a value of N that is greater than the hard heap limit, 6481 ** the the soft heap limit is set to the value of the hard heap limit. 6482 ** ^The soft heap limit is automatically enabled whenever the hard heap 6483 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6484 ** the soft heap limit is outside the range of 1..N, then the soft heap 6485 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6486 ** hard heap limit is enabled makes the soft heap limit equal to the 6487 ** hard heap limit. 6488 ** 6489 ** The memory allocation limits can also be adjusted using 6490 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6491 ** 6492 ** ^(The heap limits are not enforced in the current implementation 6493 ** if one or more of following conditions are true: 6494 ** 6495 ** <ul> 6496 ** <li> The limit value is set to zero. 6497 ** <li> Memory accounting is disabled using a combination of the 6498 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6499 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6500 ** <li> An alternative page cache implementation is specified using 6501 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6502 ** <li> The page cache allocates from its own memory pool supplied 6503 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6504 ** from the heap. 6505 ** </ul>)^ 6506 ** 6507 ** The circumstances under which SQLite will enforce the heap limits may 6508 ** changes in future releases of SQLite. 6509 */ 6510 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6511 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6512 6513 /* 6514 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6515 ** DEPRECATED 6516 ** 6517 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6518 ** interface. This routine is provided for historical compatibility 6519 ** only. All new applications should use the 6520 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6521 */ 6522 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6523 6524 6525 /* 6526 ** CAPI3REF: Extract Metadata About A Column Of A Table 6527 ** METHOD: sqlite3 6528 ** 6529 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6530 ** information about column C of table T in database D 6531 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6532 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6533 ** the final five arguments with appropriate values if the specified 6534 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6535 ** SQLITE_ERROR if the specified column does not exist. 6536 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6537 ** NULL pointer, then this routine simply checks for the existence of the 6538 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6539 ** does not. If the table name parameter T in a call to 6540 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6541 ** undefined behavior. 6542 ** 6543 ** ^The column is identified by the second, third and fourth parameters to 6544 ** this function. ^(The second parameter is either the name of the database 6545 ** (i.e. "main", "temp", or an attached database) containing the specified 6546 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6547 ** for the table using the same algorithm used by the database engine to 6548 ** resolve unqualified table references. 6549 ** 6550 ** ^The third and fourth parameters to this function are the table and column 6551 ** name of the desired column, respectively. 6552 ** 6553 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6554 ** and subsequent parameters to this function. ^Any of these arguments may be 6555 ** NULL, in which case the corresponding element of metadata is omitted. 6556 ** 6557 ** ^(<blockquote> 6558 ** <table border="1"> 6559 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6560 ** 6561 ** <tr><td> 5th <td> const char* <td> Data type 6562 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6563 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6564 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6565 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6566 ** </table> 6567 ** </blockquote>)^ 6568 ** 6569 ** ^The memory pointed to by the character pointers returned for the 6570 ** declaration type and collation sequence is valid until the next 6571 ** call to any SQLite API function. 6572 ** 6573 ** ^If the specified table is actually a view, an [error code] is returned. 6574 ** 6575 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6576 ** is not a [WITHOUT ROWID] table and an 6577 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6578 ** parameters are set for the explicitly declared column. ^(If there is no 6579 ** [INTEGER PRIMARY KEY] column, then the outputs 6580 ** for the [rowid] are set as follows: 6581 ** 6582 ** <pre> 6583 ** data type: "INTEGER" 6584 ** collation sequence: "BINARY" 6585 ** not null: 0 6586 ** primary key: 1 6587 ** auto increment: 0 6588 ** </pre>)^ 6589 ** 6590 ** ^This function causes all database schemas to be read from disk and 6591 ** parsed, if that has not already been done, and returns an error if 6592 ** any errors are encountered while loading the schema. 6593 */ 6594 SQLITE_API int sqlite3_table_column_metadata( 6595 sqlite3 *db, /* Connection handle */ 6596 const char *zDbName, /* Database name or NULL */ 6597 const char *zTableName, /* Table name */ 6598 const char *zColumnName, /* Column name */ 6599 char const **pzDataType, /* OUTPUT: Declared data type */ 6600 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6601 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6602 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6603 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6604 ); 6605 6606 /* 6607 ** CAPI3REF: Load An Extension 6608 ** METHOD: sqlite3 6609 ** 6610 ** ^This interface loads an SQLite extension library from the named file. 6611 ** 6612 ** ^The sqlite3_load_extension() interface attempts to load an 6613 ** [SQLite extension] library contained in the file zFile. If 6614 ** the file cannot be loaded directly, attempts are made to load 6615 ** with various operating-system specific extensions added. 6616 ** So for example, if "samplelib" cannot be loaded, then names like 6617 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6618 ** be tried also. 6619 ** 6620 ** ^The entry point is zProc. 6621 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6622 ** entry point name on its own. It first tries "sqlite3_extension_init". 6623 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6624 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6625 ** characters in the filename from the last "/" to the first following 6626 ** "." and omitting any initial "lib".)^ 6627 ** ^The sqlite3_load_extension() interface returns 6628 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6629 ** ^If an error occurs and pzErrMsg is not 0, then the 6630 ** [sqlite3_load_extension()] interface shall attempt to 6631 ** fill *pzErrMsg with error message text stored in memory 6632 ** obtained from [sqlite3_malloc()]. The calling function 6633 ** should free this memory by calling [sqlite3_free()]. 6634 ** 6635 ** ^Extension loading must be enabled using 6636 ** [sqlite3_enable_load_extension()] or 6637 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6638 ** prior to calling this API, 6639 ** otherwise an error will be returned. 6640 ** 6641 ** <b>Security warning:</b> It is recommended that the 6642 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6643 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6644 ** should be avoided. This will keep the SQL function [load_extension()] 6645 ** disabled and prevent SQL injections from giving attackers 6646 ** access to extension loading capabilities. 6647 ** 6648 ** See also the [load_extension() SQL function]. 6649 */ 6650 SQLITE_API int sqlite3_load_extension( 6651 sqlite3 *db, /* Load the extension into this database connection */ 6652 const char *zFile, /* Name of the shared library containing extension */ 6653 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6654 char **pzErrMsg /* Put error message here if not 0 */ 6655 ); 6656 6657 /* 6658 ** CAPI3REF: Enable Or Disable Extension Loading 6659 ** METHOD: sqlite3 6660 ** 6661 ** ^So as not to open security holes in older applications that are 6662 ** unprepared to deal with [extension loading], and as a means of disabling 6663 ** [extension loading] while evaluating user-entered SQL, the following API 6664 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6665 ** 6666 ** ^Extension loading is off by default. 6667 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6668 ** to turn extension loading on and call it with onoff==0 to turn 6669 ** it back off again. 6670 ** 6671 ** ^This interface enables or disables both the C-API 6672 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6673 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6674 ** to enable or disable only the C-API.)^ 6675 ** 6676 ** <b>Security warning:</b> It is recommended that extension loading 6677 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6678 ** rather than this interface, so the [load_extension()] SQL function 6679 ** remains disabled. This will prevent SQL injections from giving attackers 6680 ** access to extension loading capabilities. 6681 */ 6682 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6683 6684 /* 6685 ** CAPI3REF: Automatically Load Statically Linked Extensions 6686 ** 6687 ** ^This interface causes the xEntryPoint() function to be invoked for 6688 ** each new [database connection] that is created. The idea here is that 6689 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6690 ** that is to be automatically loaded into all new database connections. 6691 ** 6692 ** ^(Even though the function prototype shows that xEntryPoint() takes 6693 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6694 ** arguments and expects an integer result as if the signature of the 6695 ** entry point where as follows: 6696 ** 6697 ** <blockquote><pre> 6698 ** int xEntryPoint( 6699 ** sqlite3 *db, 6700 ** const char **pzErrMsg, 6701 ** const struct sqlite3_api_routines *pThunk 6702 ** ); 6703 ** </pre></blockquote>)^ 6704 ** 6705 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6706 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6707 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6708 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6709 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6710 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6711 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6712 ** 6713 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6714 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6715 ** will be called more than once for each database connection that is opened. 6716 ** 6717 ** See also: [sqlite3_reset_auto_extension()] 6718 ** and [sqlite3_cancel_auto_extension()] 6719 */ 6720 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6721 6722 /* 6723 ** CAPI3REF: Cancel Automatic Extension Loading 6724 ** 6725 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6726 ** initialization routine X that was registered using a prior call to 6727 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6728 ** routine returns 1 if initialization routine X was successfully 6729 ** unregistered and it returns 0 if X was not on the list of initialization 6730 ** routines. 6731 */ 6732 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6733 6734 /* 6735 ** CAPI3REF: Reset Automatic Extension Loading 6736 ** 6737 ** ^This interface disables all automatic extensions previously 6738 ** registered using [sqlite3_auto_extension()]. 6739 */ 6740 SQLITE_API void sqlite3_reset_auto_extension(void); 6741 6742 /* 6743 ** The interface to the virtual-table mechanism is currently considered 6744 ** to be experimental. The interface might change in incompatible ways. 6745 ** If this is a problem for you, do not use the interface at this time. 6746 ** 6747 ** When the virtual-table mechanism stabilizes, we will declare the 6748 ** interface fixed, support it indefinitely, and remove this comment. 6749 */ 6750 6751 /* 6752 ** Structures used by the virtual table interface 6753 */ 6754 typedef struct sqlite3_vtab sqlite3_vtab; 6755 typedef struct sqlite3_index_info sqlite3_index_info; 6756 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6757 typedef struct sqlite3_module sqlite3_module; 6758 6759 /* 6760 ** CAPI3REF: Virtual Table Object 6761 ** KEYWORDS: sqlite3_module {virtual table module} 6762 ** 6763 ** This structure, sometimes called a "virtual table module", 6764 ** defines the implementation of a [virtual table]. 6765 ** This structure consists mostly of methods for the module. 6766 ** 6767 ** ^A virtual table module is created by filling in a persistent 6768 ** instance of this structure and passing a pointer to that instance 6769 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6770 ** ^The registration remains valid until it is replaced by a different 6771 ** module or until the [database connection] closes. The content 6772 ** of this structure must not change while it is registered with 6773 ** any database connection. 6774 */ 6775 struct sqlite3_module { 6776 int iVersion; 6777 int (*xCreate)(sqlite3*, void *pAux, 6778 int argc, const char *const*argv, 6779 sqlite3_vtab **ppVTab, char**); 6780 int (*xConnect)(sqlite3*, void *pAux, 6781 int argc, const char *const*argv, 6782 sqlite3_vtab **ppVTab, char**); 6783 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6784 int (*xDisconnect)(sqlite3_vtab *pVTab); 6785 int (*xDestroy)(sqlite3_vtab *pVTab); 6786 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6787 int (*xClose)(sqlite3_vtab_cursor*); 6788 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6789 int argc, sqlite3_value **argv); 6790 int (*xNext)(sqlite3_vtab_cursor*); 6791 int (*xEof)(sqlite3_vtab_cursor*); 6792 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6793 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6794 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6795 int (*xBegin)(sqlite3_vtab *pVTab); 6796 int (*xSync)(sqlite3_vtab *pVTab); 6797 int (*xCommit)(sqlite3_vtab *pVTab); 6798 int (*xRollback)(sqlite3_vtab *pVTab); 6799 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6800 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6801 void **ppArg); 6802 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6803 /* The methods above are in version 1 of the sqlite_module object. Those 6804 ** below are for version 2 and greater. */ 6805 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6806 int (*xRelease)(sqlite3_vtab *pVTab, int); 6807 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6808 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6809 ** Those below are for version 3 and greater. */ 6810 int (*xShadowName)(const char*); 6811 }; 6812 6813 /* 6814 ** CAPI3REF: Virtual Table Indexing Information 6815 ** KEYWORDS: sqlite3_index_info 6816 ** 6817 ** The sqlite3_index_info structure and its substructures is used as part 6818 ** of the [virtual table] interface to 6819 ** pass information into and receive the reply from the [xBestIndex] 6820 ** method of a [virtual table module]. The fields under **Inputs** are the 6821 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6822 ** results into the **Outputs** fields. 6823 ** 6824 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6825 ** 6826 ** <blockquote>column OP expr</blockquote> 6827 ** 6828 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6829 ** stored in aConstraint[].op using one of the 6830 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6831 ** ^(The index of the column is stored in 6832 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6833 ** expr on the right-hand side can be evaluated (and thus the constraint 6834 ** is usable) and false if it cannot.)^ 6835 ** 6836 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6837 ** and makes other simplifications to the WHERE clause in an attempt to 6838 ** get as many WHERE clause terms into the form shown above as possible. 6839 ** ^The aConstraint[] array only reports WHERE clause terms that are 6840 ** relevant to the particular virtual table being queried. 6841 ** 6842 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6843 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6844 ** 6845 ** The colUsed field indicates which columns of the virtual table may be 6846 ** required by the current scan. Virtual table columns are numbered from 6847 ** zero in the order in which they appear within the CREATE TABLE statement 6848 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6849 ** the corresponding bit is set within the colUsed mask if the column may be 6850 ** required by SQLite. If the table has at least 64 columns and any column 6851 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6852 ** set. In other words, column iCol may be required if the expression 6853 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6854 ** non-zero. 6855 ** 6856 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6857 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6858 ** the right-hand side of the corresponding aConstraint[] is evaluated 6859 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6860 ** is true, then the constraint is assumed to be fully handled by the 6861 ** virtual table and might not be checked again by the byte code.)^ ^(The 6862 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6863 ** is left in its default setting of false, the constraint will always be 6864 ** checked separately in byte code. If the omit flag is change to true, then 6865 ** the constraint may or may not be checked in byte code. In other words, 6866 ** when the omit flag is true there is no guarantee that the constraint will 6867 ** not be checked again using byte code.)^ 6868 ** 6869 ** ^The idxNum and idxPtr values are recorded and passed into the 6870 ** [xFilter] method. 6871 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6872 ** needToFreeIdxPtr is true. 6873 ** 6874 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6875 ** the correct order to satisfy the ORDER BY clause so that no separate 6876 ** sorting step is required. 6877 ** 6878 ** ^The estimatedCost value is an estimate of the cost of a particular 6879 ** strategy. A cost of N indicates that the cost of the strategy is similar 6880 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6881 ** indicates that the expense of the operation is similar to that of a 6882 ** binary search on a unique indexed field of an SQLite table with N rows. 6883 ** 6884 ** ^The estimatedRows value is an estimate of the number of rows that 6885 ** will be returned by the strategy. 6886 ** 6887 ** The xBestIndex method may optionally populate the idxFlags field with a 6888 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6889 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6890 ** assumes that the strategy may visit at most one row. 6891 ** 6892 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6893 ** SQLite also assumes that if a call to the xUpdate() method is made as 6894 ** part of the same statement to delete or update a virtual table row and the 6895 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6896 ** any database changes. In other words, if the xUpdate() returns 6897 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6898 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6899 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6900 ** the xUpdate method are automatically rolled back by SQLite. 6901 ** 6902 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6903 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6904 ** If a virtual table extension is 6905 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6906 ** to read or write the estimatedRows field are undefined (but are likely 6907 ** to include crashing the application). The estimatedRows field should 6908 ** therefore only be used if [sqlite3_libversion_number()] returns a 6909 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6910 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6911 ** It may therefore only be used if 6912 ** sqlite3_libversion_number() returns a value greater than or equal to 6913 ** 3009000. 6914 */ 6915 struct sqlite3_index_info { 6916 /* Inputs */ 6917 int nConstraint; /* Number of entries in aConstraint */ 6918 struct sqlite3_index_constraint { 6919 int iColumn; /* Column constrained. -1 for ROWID */ 6920 unsigned char op; /* Constraint operator */ 6921 unsigned char usable; /* True if this constraint is usable */ 6922 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6923 } *aConstraint; /* Table of WHERE clause constraints */ 6924 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6925 struct sqlite3_index_orderby { 6926 int iColumn; /* Column number */ 6927 unsigned char desc; /* True for DESC. False for ASC. */ 6928 } *aOrderBy; /* The ORDER BY clause */ 6929 /* Outputs */ 6930 struct sqlite3_index_constraint_usage { 6931 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6932 unsigned char omit; /* Do not code a test for this constraint */ 6933 } *aConstraintUsage; 6934 int idxNum; /* Number used to identify the index */ 6935 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6936 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6937 int orderByConsumed; /* True if output is already ordered */ 6938 double estimatedCost; /* Estimated cost of using this index */ 6939 /* Fields below are only available in SQLite 3.8.2 and later */ 6940 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6941 /* Fields below are only available in SQLite 3.9.0 and later */ 6942 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6943 /* Fields below are only available in SQLite 3.10.0 and later */ 6944 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6945 }; 6946 6947 /* 6948 ** CAPI3REF: Virtual Table Scan Flags 6949 ** 6950 ** Virtual table implementations are allowed to set the 6951 ** [sqlite3_index_info].idxFlags field to some combination of 6952 ** these bits. 6953 */ 6954 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6955 6956 /* 6957 ** CAPI3REF: Virtual Table Constraint Operator Codes 6958 ** 6959 ** These macros define the allowed values for the 6960 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6961 ** an operator that is part of a constraint term in the wHERE clause of 6962 ** a query that uses a [virtual table]. 6963 */ 6964 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6965 #define SQLITE_INDEX_CONSTRAINT_GT 4 6966 #define SQLITE_INDEX_CONSTRAINT_LE 8 6967 #define SQLITE_INDEX_CONSTRAINT_LT 16 6968 #define SQLITE_INDEX_CONSTRAINT_GE 32 6969 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6970 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6971 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6972 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6973 #define SQLITE_INDEX_CONSTRAINT_NE 68 6974 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6975 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6976 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6977 #define SQLITE_INDEX_CONSTRAINT_IS 72 6978 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6979 6980 /* 6981 ** CAPI3REF: Register A Virtual Table Implementation 6982 ** METHOD: sqlite3 6983 ** 6984 ** ^These routines are used to register a new [virtual table module] name. 6985 ** ^Module names must be registered before 6986 ** creating a new [virtual table] using the module and before using a 6987 ** preexisting [virtual table] for the module. 6988 ** 6989 ** ^The module name is registered on the [database connection] specified 6990 ** by the first parameter. ^The name of the module is given by the 6991 ** second parameter. ^The third parameter is a pointer to 6992 ** the implementation of the [virtual table module]. ^The fourth 6993 ** parameter is an arbitrary client data pointer that is passed through 6994 ** into the [xCreate] and [xConnect] methods of the virtual table module 6995 ** when a new virtual table is be being created or reinitialized. 6996 ** 6997 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6998 ** is a pointer to a destructor for the pClientData. ^SQLite will 6999 ** invoke the destructor function (if it is not NULL) when SQLite 7000 ** no longer needs the pClientData pointer. ^The destructor will also 7001 ** be invoked if the call to sqlite3_create_module_v2() fails. 7002 ** ^The sqlite3_create_module() 7003 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7004 ** destructor. 7005 ** 7006 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7007 ** NULL then no new module is create and any existing modules with the 7008 ** same name are dropped. 7009 ** 7010 ** See also: [sqlite3_drop_modules()] 7011 */ 7012 SQLITE_API int sqlite3_create_module( 7013 sqlite3 *db, /* SQLite connection to register module with */ 7014 const char *zName, /* Name of the module */ 7015 const sqlite3_module *p, /* Methods for the module */ 7016 void *pClientData /* Client data for xCreate/xConnect */ 7017 ); 7018 SQLITE_API int sqlite3_create_module_v2( 7019 sqlite3 *db, /* SQLite connection to register module with */ 7020 const char *zName, /* Name of the module */ 7021 const sqlite3_module *p, /* Methods for the module */ 7022 void *pClientData, /* Client data for xCreate/xConnect */ 7023 void(*xDestroy)(void*) /* Module destructor function */ 7024 ); 7025 7026 /* 7027 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7028 ** METHOD: sqlite3 7029 ** 7030 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7031 ** table modules from database connection D except those named on list L. 7032 ** The L parameter must be either NULL or a pointer to an array of pointers 7033 ** to strings where the array is terminated by a single NULL pointer. 7034 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7035 ** 7036 ** See also: [sqlite3_create_module()] 7037 */ 7038 SQLITE_API int sqlite3_drop_modules( 7039 sqlite3 *db, /* Remove modules from this connection */ 7040 const char **azKeep /* Except, do not remove the ones named here */ 7041 ); 7042 7043 /* 7044 ** CAPI3REF: Virtual Table Instance Object 7045 ** KEYWORDS: sqlite3_vtab 7046 ** 7047 ** Every [virtual table module] implementation uses a subclass 7048 ** of this object to describe a particular instance 7049 ** of the [virtual table]. Each subclass will 7050 ** be tailored to the specific needs of the module implementation. 7051 ** The purpose of this superclass is to define certain fields that are 7052 ** common to all module implementations. 7053 ** 7054 ** ^Virtual tables methods can set an error message by assigning a 7055 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7056 ** take care that any prior string is freed by a call to [sqlite3_free()] 7057 ** prior to assigning a new string to zErrMsg. ^After the error message 7058 ** is delivered up to the client application, the string will be automatically 7059 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7060 */ 7061 struct sqlite3_vtab { 7062 const sqlite3_module *pModule; /* The module for this virtual table */ 7063 int nRef; /* Number of open cursors */ 7064 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7065 /* Virtual table implementations will typically add additional fields */ 7066 }; 7067 7068 /* 7069 ** CAPI3REF: Virtual Table Cursor Object 7070 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7071 ** 7072 ** Every [virtual table module] implementation uses a subclass of the 7073 ** following structure to describe cursors that point into the 7074 ** [virtual table] and are used 7075 ** to loop through the virtual table. Cursors are created using the 7076 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7077 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7078 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7079 ** of the module. Each module implementation will define 7080 ** the content of a cursor structure to suit its own needs. 7081 ** 7082 ** This superclass exists in order to define fields of the cursor that 7083 ** are common to all implementations. 7084 */ 7085 struct sqlite3_vtab_cursor { 7086 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7087 /* Virtual table implementations will typically add additional fields */ 7088 }; 7089 7090 /* 7091 ** CAPI3REF: Declare The Schema Of A Virtual Table 7092 ** 7093 ** ^The [xCreate] and [xConnect] methods of a 7094 ** [virtual table module] call this interface 7095 ** to declare the format (the names and datatypes of the columns) of 7096 ** the virtual tables they implement. 7097 */ 7098 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7099 7100 /* 7101 ** CAPI3REF: Overload A Function For A Virtual Table 7102 ** METHOD: sqlite3 7103 ** 7104 ** ^(Virtual tables can provide alternative implementations of functions 7105 ** using the [xFindFunction] method of the [virtual table module]. 7106 ** But global versions of those functions 7107 ** must exist in order to be overloaded.)^ 7108 ** 7109 ** ^(This API makes sure a global version of a function with a particular 7110 ** name and number of parameters exists. If no such function exists 7111 ** before this API is called, a new function is created.)^ ^The implementation 7112 ** of the new function always causes an exception to be thrown. So 7113 ** the new function is not good for anything by itself. Its only 7114 ** purpose is to be a placeholder function that can be overloaded 7115 ** by a [virtual table]. 7116 */ 7117 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7118 7119 /* 7120 ** The interface to the virtual-table mechanism defined above (back up 7121 ** to a comment remarkably similar to this one) is currently considered 7122 ** to be experimental. The interface might change in incompatible ways. 7123 ** If this is a problem for you, do not use the interface at this time. 7124 ** 7125 ** When the virtual-table mechanism stabilizes, we will declare the 7126 ** interface fixed, support it indefinitely, and remove this comment. 7127 */ 7128 7129 /* 7130 ** CAPI3REF: A Handle To An Open BLOB 7131 ** KEYWORDS: {BLOB handle} {BLOB handles} 7132 ** 7133 ** An instance of this object represents an open BLOB on which 7134 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7135 ** ^Objects of this type are created by [sqlite3_blob_open()] 7136 ** and destroyed by [sqlite3_blob_close()]. 7137 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7138 ** can be used to read or write small subsections of the BLOB. 7139 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7140 */ 7141 typedef struct sqlite3_blob sqlite3_blob; 7142 7143 /* 7144 ** CAPI3REF: Open A BLOB For Incremental I/O 7145 ** METHOD: sqlite3 7146 ** CONSTRUCTOR: sqlite3_blob 7147 ** 7148 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7149 ** in row iRow, column zColumn, table zTable in database zDb; 7150 ** in other words, the same BLOB that would be selected by: 7151 ** 7152 ** <pre> 7153 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7154 ** </pre>)^ 7155 ** 7156 ** ^(Parameter zDb is not the filename that contains the database, but 7157 ** rather the symbolic name of the database. For attached databases, this is 7158 ** the name that appears after the AS keyword in the [ATTACH] statement. 7159 ** For the main database file, the database name is "main". For TEMP 7160 ** tables, the database name is "temp".)^ 7161 ** 7162 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7163 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7164 ** read-only access. 7165 ** 7166 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7167 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7168 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7169 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7170 ** on *ppBlob after this function it returns. 7171 ** 7172 ** This function fails with SQLITE_ERROR if any of the following are true: 7173 ** <ul> 7174 ** <li> ^(Database zDb does not exist)^, 7175 ** <li> ^(Table zTable does not exist within database zDb)^, 7176 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7177 ** <li> ^(Column zColumn does not exist)^, 7178 ** <li> ^(Row iRow is not present in the table)^, 7179 ** <li> ^(The specified column of row iRow contains a value that is not 7180 ** a TEXT or BLOB value)^, 7181 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7182 ** constraint and the blob is being opened for read/write access)^, 7183 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7184 ** column zColumn is part of a [child key] definition and the blob is 7185 ** being opened for read/write access)^. 7186 ** </ul> 7187 ** 7188 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7189 ** [database connection] error code and message accessible via 7190 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7191 ** 7192 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7193 ** [sqlite3_blob_read()] interface and modified by using 7194 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7195 ** different row of the same table using the [sqlite3_blob_reopen()] 7196 ** interface. However, the column, table, or database of a [BLOB handle] 7197 ** cannot be changed after the [BLOB handle] is opened. 7198 ** 7199 ** ^(If the row that a BLOB handle points to is modified by an 7200 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7201 ** then the BLOB handle is marked as "expired". 7202 ** This is true if any column of the row is changed, even a column 7203 ** other than the one the BLOB handle is open on.)^ 7204 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7205 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7206 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7207 ** rolled back by the expiration of the BLOB. Such changes will eventually 7208 ** commit if the transaction continues to completion.)^ 7209 ** 7210 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7211 ** the opened blob. ^The size of a blob may not be changed by this 7212 ** interface. Use the [UPDATE] SQL command to change the size of a 7213 ** blob. 7214 ** 7215 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7216 ** and the built-in [zeroblob] SQL function may be used to create a 7217 ** zero-filled blob to read or write using the incremental-blob interface. 7218 ** 7219 ** To avoid a resource leak, every open [BLOB handle] should eventually 7220 ** be released by a call to [sqlite3_blob_close()]. 7221 ** 7222 ** See also: [sqlite3_blob_close()], 7223 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7224 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7225 */ 7226 SQLITE_API int sqlite3_blob_open( 7227 sqlite3*, 7228 const char *zDb, 7229 const char *zTable, 7230 const char *zColumn, 7231 sqlite3_int64 iRow, 7232 int flags, 7233 sqlite3_blob **ppBlob 7234 ); 7235 7236 /* 7237 ** CAPI3REF: Move a BLOB Handle to a New Row 7238 ** METHOD: sqlite3_blob 7239 ** 7240 ** ^This function is used to move an existing [BLOB handle] so that it points 7241 ** to a different row of the same database table. ^The new row is identified 7242 ** by the rowid value passed as the second argument. Only the row can be 7243 ** changed. ^The database, table and column on which the blob handle is open 7244 ** remain the same. Moving an existing [BLOB handle] to a new row is 7245 ** faster than closing the existing handle and opening a new one. 7246 ** 7247 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7248 ** it must exist and there must be either a blob or text value stored in 7249 ** the nominated column.)^ ^If the new row is not present in the table, or if 7250 ** it does not contain a blob or text value, or if another error occurs, an 7251 ** SQLite error code is returned and the blob handle is considered aborted. 7252 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7253 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7254 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7255 ** always returns zero. 7256 ** 7257 ** ^This function sets the database handle error code and message. 7258 */ 7259 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7260 7261 /* 7262 ** CAPI3REF: Close A BLOB Handle 7263 ** DESTRUCTOR: sqlite3_blob 7264 ** 7265 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7266 ** unconditionally. Even if this routine returns an error code, the 7267 ** handle is still closed.)^ 7268 ** 7269 ** ^If the blob handle being closed was opened for read-write access, and if 7270 ** the database is in auto-commit mode and there are no other open read-write 7271 ** blob handles or active write statements, the current transaction is 7272 ** committed. ^If an error occurs while committing the transaction, an error 7273 ** code is returned and the transaction rolled back. 7274 ** 7275 ** Calling this function with an argument that is not a NULL pointer or an 7276 ** open blob handle results in undefined behaviour. ^Calling this routine 7277 ** with a null pointer (such as would be returned by a failed call to 7278 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7279 ** is passed a valid open blob handle, the values returned by the 7280 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7281 */ 7282 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7283 7284 /* 7285 ** CAPI3REF: Return The Size Of An Open BLOB 7286 ** METHOD: sqlite3_blob 7287 ** 7288 ** ^Returns the size in bytes of the BLOB accessible via the 7289 ** successfully opened [BLOB handle] in its only argument. ^The 7290 ** incremental blob I/O routines can only read or overwriting existing 7291 ** blob content; they cannot change the size of a blob. 7292 ** 7293 ** This routine only works on a [BLOB handle] which has been created 7294 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7295 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7296 ** to this routine results in undefined and probably undesirable behavior. 7297 */ 7298 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7299 7300 /* 7301 ** CAPI3REF: Read Data From A BLOB Incrementally 7302 ** METHOD: sqlite3_blob 7303 ** 7304 ** ^(This function is used to read data from an open [BLOB handle] into a 7305 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7306 ** from the open BLOB, starting at offset iOffset.)^ 7307 ** 7308 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7309 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7310 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7311 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7312 ** can be determined using the [sqlite3_blob_bytes()] interface. 7313 ** 7314 ** ^An attempt to read from an expired [BLOB handle] fails with an 7315 ** error code of [SQLITE_ABORT]. 7316 ** 7317 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7318 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7319 ** 7320 ** This routine only works on a [BLOB handle] which has been created 7321 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7322 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7323 ** to this routine results in undefined and probably undesirable behavior. 7324 ** 7325 ** See also: [sqlite3_blob_write()]. 7326 */ 7327 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7328 7329 /* 7330 ** CAPI3REF: Write Data Into A BLOB Incrementally 7331 ** METHOD: sqlite3_blob 7332 ** 7333 ** ^(This function is used to write data into an open [BLOB handle] from a 7334 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7335 ** into the open BLOB, starting at offset iOffset.)^ 7336 ** 7337 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7338 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7339 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7340 ** [database connection] error code and message accessible via 7341 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7342 ** 7343 ** ^If the [BLOB handle] passed as the first argument was not opened for 7344 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7345 ** this function returns [SQLITE_READONLY]. 7346 ** 7347 ** This function may only modify the contents of the BLOB; it is 7348 ** not possible to increase the size of a BLOB using this API. 7349 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7350 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7351 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7352 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7353 ** than zero [SQLITE_ERROR] is returned and no data is written. 7354 ** 7355 ** ^An attempt to write to an expired [BLOB handle] fails with an 7356 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7357 ** before the [BLOB handle] expired are not rolled back by the 7358 ** expiration of the handle, though of course those changes might 7359 ** have been overwritten by the statement that expired the BLOB handle 7360 ** or by other independent statements. 7361 ** 7362 ** This routine only works on a [BLOB handle] which has been created 7363 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7364 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7365 ** to this routine results in undefined and probably undesirable behavior. 7366 ** 7367 ** See also: [sqlite3_blob_read()]. 7368 */ 7369 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7370 7371 /* 7372 ** CAPI3REF: Virtual File System Objects 7373 ** 7374 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7375 ** that SQLite uses to interact 7376 ** with the underlying operating system. Most SQLite builds come with a 7377 ** single default VFS that is appropriate for the host computer. 7378 ** New VFSes can be registered and existing VFSes can be unregistered. 7379 ** The following interfaces are provided. 7380 ** 7381 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7382 ** ^Names are case sensitive. 7383 ** ^Names are zero-terminated UTF-8 strings. 7384 ** ^If there is no match, a NULL pointer is returned. 7385 ** ^If zVfsName is NULL then the default VFS is returned. 7386 ** 7387 ** ^New VFSes are registered with sqlite3_vfs_register(). 7388 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7389 ** ^The same VFS can be registered multiple times without injury. 7390 ** ^To make an existing VFS into the default VFS, register it again 7391 ** with the makeDflt flag set. If two different VFSes with the 7392 ** same name are registered, the behavior is undefined. If a 7393 ** VFS is registered with a name that is NULL or an empty string, 7394 ** then the behavior is undefined. 7395 ** 7396 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7397 ** ^(If the default VFS is unregistered, another VFS is chosen as 7398 ** the default. The choice for the new VFS is arbitrary.)^ 7399 */ 7400 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7401 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7402 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7403 7404 /* 7405 ** CAPI3REF: Mutexes 7406 ** 7407 ** The SQLite core uses these routines for thread 7408 ** synchronization. Though they are intended for internal 7409 ** use by SQLite, code that links against SQLite is 7410 ** permitted to use any of these routines. 7411 ** 7412 ** The SQLite source code contains multiple implementations 7413 ** of these mutex routines. An appropriate implementation 7414 ** is selected automatically at compile-time. The following 7415 ** implementations are available in the SQLite core: 7416 ** 7417 ** <ul> 7418 ** <li> SQLITE_MUTEX_PTHREADS 7419 ** <li> SQLITE_MUTEX_W32 7420 ** <li> SQLITE_MUTEX_NOOP 7421 ** </ul> 7422 ** 7423 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7424 ** that does no real locking and is appropriate for use in 7425 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7426 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7427 ** and Windows. 7428 ** 7429 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7430 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7431 ** implementation is included with the library. In this case the 7432 ** application must supply a custom mutex implementation using the 7433 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7434 ** before calling sqlite3_initialize() or any other public sqlite3_ 7435 ** function that calls sqlite3_initialize(). 7436 ** 7437 ** ^The sqlite3_mutex_alloc() routine allocates a new 7438 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7439 ** routine returns NULL if it is unable to allocate the requested 7440 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7441 ** integer constants: 7442 ** 7443 ** <ul> 7444 ** <li> SQLITE_MUTEX_FAST 7445 ** <li> SQLITE_MUTEX_RECURSIVE 7446 ** <li> SQLITE_MUTEX_STATIC_MAIN 7447 ** <li> SQLITE_MUTEX_STATIC_MEM 7448 ** <li> SQLITE_MUTEX_STATIC_OPEN 7449 ** <li> SQLITE_MUTEX_STATIC_PRNG 7450 ** <li> SQLITE_MUTEX_STATIC_LRU 7451 ** <li> SQLITE_MUTEX_STATIC_PMEM 7452 ** <li> SQLITE_MUTEX_STATIC_APP1 7453 ** <li> SQLITE_MUTEX_STATIC_APP2 7454 ** <li> SQLITE_MUTEX_STATIC_APP3 7455 ** <li> SQLITE_MUTEX_STATIC_VFS1 7456 ** <li> SQLITE_MUTEX_STATIC_VFS2 7457 ** <li> SQLITE_MUTEX_STATIC_VFS3 7458 ** </ul> 7459 ** 7460 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7461 ** cause sqlite3_mutex_alloc() to create 7462 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7463 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7464 ** The mutex implementation does not need to make a distinction 7465 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7466 ** not want to. SQLite will only request a recursive mutex in 7467 ** cases where it really needs one. If a faster non-recursive mutex 7468 ** implementation is available on the host platform, the mutex subsystem 7469 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7470 ** 7471 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7472 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7473 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7474 ** used by the current version of SQLite. Future versions of SQLite 7475 ** may add additional static mutexes. Static mutexes are for internal 7476 ** use by SQLite only. Applications that use SQLite mutexes should 7477 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7478 ** SQLITE_MUTEX_RECURSIVE. 7479 ** 7480 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7481 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7482 ** returns a different mutex on every call. ^For the static 7483 ** mutex types, the same mutex is returned on every call that has 7484 ** the same type number. 7485 ** 7486 ** ^The sqlite3_mutex_free() routine deallocates a previously 7487 ** allocated dynamic mutex. Attempting to deallocate a static 7488 ** mutex results in undefined behavior. 7489 ** 7490 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7491 ** to enter a mutex. ^If another thread is already within the mutex, 7492 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7493 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7494 ** upon successful entry. ^(Mutexes created using 7495 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7496 ** In such cases, the 7497 ** mutex must be exited an equal number of times before another thread 7498 ** can enter.)^ If the same thread tries to enter any mutex other 7499 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7500 ** 7501 ** ^(Some systems (for example, Windows 95) do not support the operation 7502 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7503 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7504 ** sqlite3_mutex_try() as an optimization so this is acceptable 7505 ** behavior.)^ 7506 ** 7507 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7508 ** previously entered by the same thread. The behavior 7509 ** is undefined if the mutex is not currently entered by the 7510 ** calling thread or is not currently allocated. 7511 ** 7512 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7513 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7514 ** behave as no-ops. 7515 ** 7516 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7517 */ 7518 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7519 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7520 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7521 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7522 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7523 7524 /* 7525 ** CAPI3REF: Mutex Methods Object 7526 ** 7527 ** An instance of this structure defines the low-level routines 7528 ** used to allocate and use mutexes. 7529 ** 7530 ** Usually, the default mutex implementations provided by SQLite are 7531 ** sufficient, however the application has the option of substituting a custom 7532 ** implementation for specialized deployments or systems for which SQLite 7533 ** does not provide a suitable implementation. In this case, the application 7534 ** creates and populates an instance of this structure to pass 7535 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7536 ** Additionally, an instance of this structure can be used as an 7537 ** output variable when querying the system for the current mutex 7538 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7539 ** 7540 ** ^The xMutexInit method defined by this structure is invoked as 7541 ** part of system initialization by the sqlite3_initialize() function. 7542 ** ^The xMutexInit routine is called by SQLite exactly once for each 7543 ** effective call to [sqlite3_initialize()]. 7544 ** 7545 ** ^The xMutexEnd method defined by this structure is invoked as 7546 ** part of system shutdown by the sqlite3_shutdown() function. The 7547 ** implementation of this method is expected to release all outstanding 7548 ** resources obtained by the mutex methods implementation, especially 7549 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7550 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7551 ** 7552 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7553 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7554 ** xMutexNotheld) implement the following interfaces (respectively): 7555 ** 7556 ** <ul> 7557 ** <li> [sqlite3_mutex_alloc()] </li> 7558 ** <li> [sqlite3_mutex_free()] </li> 7559 ** <li> [sqlite3_mutex_enter()] </li> 7560 ** <li> [sqlite3_mutex_try()] </li> 7561 ** <li> [sqlite3_mutex_leave()] </li> 7562 ** <li> [sqlite3_mutex_held()] </li> 7563 ** <li> [sqlite3_mutex_notheld()] </li> 7564 ** </ul>)^ 7565 ** 7566 ** The only difference is that the public sqlite3_XXX functions enumerated 7567 ** above silently ignore any invocations that pass a NULL pointer instead 7568 ** of a valid mutex handle. The implementations of the methods defined 7569 ** by this structure are not required to handle this case. The results 7570 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7571 ** (i.e. it is acceptable to provide an implementation that segfaults if 7572 ** it is passed a NULL pointer). 7573 ** 7574 ** The xMutexInit() method must be threadsafe. It must be harmless to 7575 ** invoke xMutexInit() multiple times within the same process and without 7576 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7577 ** xMutexInit() must be no-ops. 7578 ** 7579 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7580 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7581 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7582 ** memory allocation for a fast or recursive mutex. 7583 ** 7584 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7585 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7586 ** If xMutexInit fails in any way, it is expected to clean up after itself 7587 ** prior to returning. 7588 */ 7589 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7590 struct sqlite3_mutex_methods { 7591 int (*xMutexInit)(void); 7592 int (*xMutexEnd)(void); 7593 sqlite3_mutex *(*xMutexAlloc)(int); 7594 void (*xMutexFree)(sqlite3_mutex *); 7595 void (*xMutexEnter)(sqlite3_mutex *); 7596 int (*xMutexTry)(sqlite3_mutex *); 7597 void (*xMutexLeave)(sqlite3_mutex *); 7598 int (*xMutexHeld)(sqlite3_mutex *); 7599 int (*xMutexNotheld)(sqlite3_mutex *); 7600 }; 7601 7602 /* 7603 ** CAPI3REF: Mutex Verification Routines 7604 ** 7605 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7606 ** are intended for use inside assert() statements. The SQLite core 7607 ** never uses these routines except inside an assert() and applications 7608 ** are advised to follow the lead of the core. The SQLite core only 7609 ** provides implementations for these routines when it is compiled 7610 ** with the SQLITE_DEBUG flag. External mutex implementations 7611 ** are only required to provide these routines if SQLITE_DEBUG is 7612 ** defined and if NDEBUG is not defined. 7613 ** 7614 ** These routines should return true if the mutex in their argument 7615 ** is held or not held, respectively, by the calling thread. 7616 ** 7617 ** The implementation is not required to provide versions of these 7618 ** routines that actually work. If the implementation does not provide working 7619 ** versions of these routines, it should at least provide stubs that always 7620 ** return true so that one does not get spurious assertion failures. 7621 ** 7622 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7623 ** the routine should return 1. This seems counter-intuitive since 7624 ** clearly the mutex cannot be held if it does not exist. But 7625 ** the reason the mutex does not exist is because the build is not 7626 ** using mutexes. And we do not want the assert() containing the 7627 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7628 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7629 ** interface should also return 1 when given a NULL pointer. 7630 */ 7631 #ifndef NDEBUG 7632 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7633 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7634 #endif 7635 7636 /* 7637 ** CAPI3REF: Mutex Types 7638 ** 7639 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7640 ** which is one of these integer constants. 7641 ** 7642 ** The set of static mutexes may change from one SQLite release to the 7643 ** next. Applications that override the built-in mutex logic must be 7644 ** prepared to accommodate additional static mutexes. 7645 */ 7646 #define SQLITE_MUTEX_FAST 0 7647 #define SQLITE_MUTEX_RECURSIVE 1 7648 #define SQLITE_MUTEX_STATIC_MAIN 2 7649 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7650 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7651 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7652 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7653 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7654 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7655 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7656 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7657 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7658 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7659 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7660 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7661 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7662 7663 /* Legacy compatibility: */ 7664 #define SQLITE_MUTEX_STATIC_MASTER 2 7665 7666 7667 /* 7668 ** CAPI3REF: Retrieve the mutex for a database connection 7669 ** METHOD: sqlite3 7670 ** 7671 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7672 ** serializes access to the [database connection] given in the argument 7673 ** when the [threading mode] is Serialized. 7674 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7675 ** routine returns a NULL pointer. 7676 */ 7677 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7678 7679 /* 7680 ** CAPI3REF: Low-Level Control Of Database Files 7681 ** METHOD: sqlite3 7682 ** KEYWORDS: {file control} 7683 ** 7684 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7685 ** xFileControl method for the [sqlite3_io_methods] object associated 7686 ** with a particular database identified by the second argument. ^The 7687 ** name of the database is "main" for the main database or "temp" for the 7688 ** TEMP database, or the name that appears after the AS keyword for 7689 ** databases that are added using the [ATTACH] SQL command. 7690 ** ^A NULL pointer can be used in place of "main" to refer to the 7691 ** main database file. 7692 ** ^The third and fourth parameters to this routine 7693 ** are passed directly through to the second and third parameters of 7694 ** the xFileControl method. ^The return value of the xFileControl 7695 ** method becomes the return value of this routine. 7696 ** 7697 ** A few opcodes for [sqlite3_file_control()] are handled directly 7698 ** by the SQLite core and never invoke the 7699 ** sqlite3_io_methods.xFileControl method. 7700 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7701 ** a pointer to the underlying [sqlite3_file] object to be written into 7702 ** the space pointed to by the 4th parameter. The 7703 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7704 ** the [sqlite3_file] object associated with the journal file instead of 7705 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7706 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7707 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7708 ** from the pager. 7709 ** 7710 ** ^If the second parameter (zDbName) does not match the name of any 7711 ** open database file, then SQLITE_ERROR is returned. ^This error 7712 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7713 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7714 ** also return SQLITE_ERROR. There is no way to distinguish between 7715 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7716 ** xFileControl method. 7717 ** 7718 ** See also: [file control opcodes] 7719 */ 7720 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7721 7722 /* 7723 ** CAPI3REF: Testing Interface 7724 ** 7725 ** ^The sqlite3_test_control() interface is used to read out internal 7726 ** state of SQLite and to inject faults into SQLite for testing 7727 ** purposes. ^The first parameter is an operation code that determines 7728 ** the number, meaning, and operation of all subsequent parameters. 7729 ** 7730 ** This interface is not for use by applications. It exists solely 7731 ** for verifying the correct operation of the SQLite library. Depending 7732 ** on how the SQLite library is compiled, this interface might not exist. 7733 ** 7734 ** The details of the operation codes, their meanings, the parameters 7735 ** they take, and what they do are all subject to change without notice. 7736 ** Unlike most of the SQLite API, this function is not guaranteed to 7737 ** operate consistently from one release to the next. 7738 */ 7739 SQLITE_API int sqlite3_test_control(int op, ...); 7740 7741 /* 7742 ** CAPI3REF: Testing Interface Operation Codes 7743 ** 7744 ** These constants are the valid operation code parameters used 7745 ** as the first argument to [sqlite3_test_control()]. 7746 ** 7747 ** These parameters and their meanings are subject to change 7748 ** without notice. These values are for testing purposes only. 7749 ** Applications should not use any of these parameters or the 7750 ** [sqlite3_test_control()] interface. 7751 */ 7752 #define SQLITE_TESTCTRL_FIRST 5 7753 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7754 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7755 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7756 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7757 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7758 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7759 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7760 #define SQLITE_TESTCTRL_ASSERT 12 7761 #define SQLITE_TESTCTRL_ALWAYS 13 7762 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7763 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7764 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7765 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7766 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7767 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7768 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7769 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7770 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7771 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7772 #define SQLITE_TESTCTRL_BYTEORDER 22 7773 #define SQLITE_TESTCTRL_ISINIT 23 7774 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7775 #define SQLITE_TESTCTRL_IMPOSTER 25 7776 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7777 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 7778 #define SQLITE_TESTCTRL_PRNG_SEED 28 7779 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7780 #define SQLITE_TESTCTRL_SEEK_COUNT 30 7781 #define SQLITE_TESTCTRL_TRACEFLAGS 31 7782 #define SQLITE_TESTCTRL_LAST 31 /* Largest TESTCTRL */ 7783 7784 /* 7785 ** CAPI3REF: SQL Keyword Checking 7786 ** 7787 ** These routines provide access to the set of SQL language keywords 7788 ** recognized by SQLite. Applications can uses these routines to determine 7789 ** whether or not a specific identifier needs to be escaped (for example, 7790 ** by enclosing in double-quotes) so as not to confuse the parser. 7791 ** 7792 ** The sqlite3_keyword_count() interface returns the number of distinct 7793 ** keywords understood by SQLite. 7794 ** 7795 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7796 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7797 ** of bytes in the keyword into *L. The string that *Z points to is not 7798 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7799 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7800 ** or L are NULL or invalid pointers then calls to 7801 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7802 ** 7803 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7804 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7805 ** if it is and zero if not. 7806 ** 7807 ** The parser used by SQLite is forgiving. It is often possible to use 7808 ** a keyword as an identifier as long as such use does not result in a 7809 ** parsing ambiguity. For example, the statement 7810 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7811 ** creates a new table named "BEGIN" with three columns named 7812 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7813 ** using keywords as identifiers. Common techniques used to avoid keyword 7814 ** name collisions include: 7815 ** <ul> 7816 ** <li> Put all identifier names inside double-quotes. This is the official 7817 ** SQL way to escape identifier names. 7818 ** <li> Put identifier names inside [...]. This is not standard SQL, 7819 ** but it is what SQL Server does and so lots of programmers use this 7820 ** technique. 7821 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7822 ** with "Z". 7823 ** <li> Include a digit somewhere in every identifier name. 7824 ** </ul> 7825 ** 7826 ** Note that the number of keywords understood by SQLite can depend on 7827 ** compile-time options. For example, "VACUUM" is not a keyword if 7828 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7829 ** new keywords may be added to future releases of SQLite. 7830 */ 7831 SQLITE_API int sqlite3_keyword_count(void); 7832 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7833 SQLITE_API int sqlite3_keyword_check(const char*,int); 7834 7835 /* 7836 ** CAPI3REF: Dynamic String Object 7837 ** KEYWORDS: {dynamic string} 7838 ** 7839 ** An instance of the sqlite3_str object contains a dynamically-sized 7840 ** string under construction. 7841 ** 7842 ** The lifecycle of an sqlite3_str object is as follows: 7843 ** <ol> 7844 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7845 ** <li> ^Text is appended to the sqlite3_str object using various 7846 ** methods, such as [sqlite3_str_appendf()]. 7847 ** <li> ^The sqlite3_str object is destroyed and the string it created 7848 ** is returned using the [sqlite3_str_finish()] interface. 7849 ** </ol> 7850 */ 7851 typedef struct sqlite3_str sqlite3_str; 7852 7853 /* 7854 ** CAPI3REF: Create A New Dynamic String Object 7855 ** CONSTRUCTOR: sqlite3_str 7856 ** 7857 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7858 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7859 ** [sqlite3_str_new()] must be freed by a subsequent call to 7860 ** [sqlite3_str_finish(X)]. 7861 ** 7862 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7863 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7864 ** error the returned object might be a special singleton that will 7865 ** silently reject new text, always return SQLITE_NOMEM from 7866 ** [sqlite3_str_errcode()], always return 0 for 7867 ** [sqlite3_str_length()], and always return NULL from 7868 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7869 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7870 ** to any of the other [sqlite3_str] methods. 7871 ** 7872 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7873 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7874 ** length of the string contained in the [sqlite3_str] object will be 7875 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7876 ** of [SQLITE_MAX_LENGTH]. 7877 */ 7878 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7879 7880 /* 7881 ** CAPI3REF: Finalize A Dynamic String 7882 ** DESTRUCTOR: sqlite3_str 7883 ** 7884 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7885 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7886 ** that contains the constructed string. The calling application should 7887 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7888 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7889 ** errors were encountered during construction of the string. ^The 7890 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7891 ** string in [sqlite3_str] object X is zero bytes long. 7892 */ 7893 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7894 7895 /* 7896 ** CAPI3REF: Add Content To A Dynamic String 7897 ** METHOD: sqlite3_str 7898 ** 7899 ** These interfaces add content to an sqlite3_str object previously obtained 7900 ** from [sqlite3_str_new()]. 7901 ** 7902 ** ^The [sqlite3_str_appendf(X,F,...)] and 7903 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7904 ** functionality of SQLite to append formatted text onto the end of 7905 ** [sqlite3_str] object X. 7906 ** 7907 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7908 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7909 ** S must contain at least N non-zero bytes of content. To append a 7910 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7911 ** method instead. 7912 ** 7913 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7914 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7915 ** 7916 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7917 ** single-byte character C onto the end of [sqlite3_str] object X. 7918 ** ^This method can be used, for example, to add whitespace indentation. 7919 ** 7920 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7921 ** inside [sqlite3_str] object X back to zero bytes in length. 7922 ** 7923 ** These methods do not return a result code. ^If an error occurs, that fact 7924 ** is recorded in the [sqlite3_str] object and can be recovered by a 7925 ** subsequent call to [sqlite3_str_errcode(X)]. 7926 */ 7927 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7928 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7929 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7930 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7931 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7932 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7933 7934 /* 7935 ** CAPI3REF: Status Of A Dynamic String 7936 ** METHOD: sqlite3_str 7937 ** 7938 ** These interfaces return the current status of an [sqlite3_str] object. 7939 ** 7940 ** ^If any prior errors have occurred while constructing the dynamic string 7941 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7942 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7943 ** [SQLITE_NOMEM] following any out-of-memory error, or 7944 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7945 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7946 ** 7947 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7948 ** of the dynamic string under construction in [sqlite3_str] object X. 7949 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7950 ** zero-termination byte. 7951 ** 7952 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7953 ** content of the dynamic string under construction in X. The value 7954 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7955 ** and might be freed or altered by any subsequent method on the same 7956 ** [sqlite3_str] object. Applications must not used the pointer returned 7957 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7958 ** object. ^Applications may change the content of the string returned 7959 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7960 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7961 ** write any byte after any subsequent sqlite3_str method call. 7962 */ 7963 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7964 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7965 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7966 7967 /* 7968 ** CAPI3REF: SQLite Runtime Status 7969 ** 7970 ** ^These interfaces are used to retrieve runtime status information 7971 ** about the performance of SQLite, and optionally to reset various 7972 ** highwater marks. ^The first argument is an integer code for 7973 ** the specific parameter to measure. ^(Recognized integer codes 7974 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7975 ** ^The current value of the parameter is returned into *pCurrent. 7976 ** ^The highest recorded value is returned in *pHighwater. ^If the 7977 ** resetFlag is true, then the highest record value is reset after 7978 ** *pHighwater is written. ^(Some parameters do not record the highest 7979 ** value. For those parameters 7980 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7981 ** ^(Other parameters record only the highwater mark and not the current 7982 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7983 ** 7984 ** ^The sqlite3_status() and sqlite3_status64() routines return 7985 ** SQLITE_OK on success and a non-zero [error code] on failure. 7986 ** 7987 ** If either the current value or the highwater mark is too large to 7988 ** be represented by a 32-bit integer, then the values returned by 7989 ** sqlite3_status() are undefined. 7990 ** 7991 ** See also: [sqlite3_db_status()] 7992 */ 7993 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7994 SQLITE_API int sqlite3_status64( 7995 int op, 7996 sqlite3_int64 *pCurrent, 7997 sqlite3_int64 *pHighwater, 7998 int resetFlag 7999 ); 8000 8001 8002 /* 8003 ** CAPI3REF: Status Parameters 8004 ** KEYWORDS: {status parameters} 8005 ** 8006 ** These integer constants designate various run-time status parameters 8007 ** that can be returned by [sqlite3_status()]. 8008 ** 8009 ** <dl> 8010 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8011 ** <dd>This parameter is the current amount of memory checked out 8012 ** using [sqlite3_malloc()], either directly or indirectly. The 8013 ** figure includes calls made to [sqlite3_malloc()] by the application 8014 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8015 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8016 ** this parameter. The amount returned is the sum of the allocation 8017 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8018 ** 8019 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8020 ** <dd>This parameter records the largest memory allocation request 8021 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8022 ** internal equivalents). Only the value returned in the 8023 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8024 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8025 ** 8026 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8027 ** <dd>This parameter records the number of separate memory allocations 8028 ** currently checked out.</dd>)^ 8029 ** 8030 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8031 ** <dd>This parameter returns the number of pages used out of the 8032 ** [pagecache memory allocator] that was configured using 8033 ** [SQLITE_CONFIG_PAGECACHE]. The 8034 ** value returned is in pages, not in bytes.</dd>)^ 8035 ** 8036 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8037 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8038 ** <dd>This parameter returns the number of bytes of page cache 8039 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8040 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8041 ** returned value includes allocations that overflowed because they 8042 ** where too large (they were larger than the "sz" parameter to 8043 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8044 ** no space was left in the page cache.</dd>)^ 8045 ** 8046 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8047 ** <dd>This parameter records the largest memory allocation request 8048 ** handed to the [pagecache memory allocator]. Only the value returned in the 8049 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8050 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8051 ** 8052 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8053 ** <dd>No longer used.</dd> 8054 ** 8055 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8056 ** <dd>No longer used.</dd> 8057 ** 8058 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8059 ** <dd>No longer used.</dd> 8060 ** 8061 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8062 ** <dd>The *pHighwater parameter records the deepest parser stack. 8063 ** The *pCurrent value is undefined. The *pHighwater value is only 8064 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8065 ** </dl> 8066 ** 8067 ** New status parameters may be added from time to time. 8068 */ 8069 #define SQLITE_STATUS_MEMORY_USED 0 8070 #define SQLITE_STATUS_PAGECACHE_USED 1 8071 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8072 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8073 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8074 #define SQLITE_STATUS_MALLOC_SIZE 5 8075 #define SQLITE_STATUS_PARSER_STACK 6 8076 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8077 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8078 #define SQLITE_STATUS_MALLOC_COUNT 9 8079 8080 /* 8081 ** CAPI3REF: Database Connection Status 8082 ** METHOD: sqlite3 8083 ** 8084 ** ^This interface is used to retrieve runtime status information 8085 ** about a single [database connection]. ^The first argument is the 8086 ** database connection object to be interrogated. ^The second argument 8087 ** is an integer constant, taken from the set of 8088 ** [SQLITE_DBSTATUS options], that 8089 ** determines the parameter to interrogate. The set of 8090 ** [SQLITE_DBSTATUS options] is likely 8091 ** to grow in future releases of SQLite. 8092 ** 8093 ** ^The current value of the requested parameter is written into *pCur 8094 ** and the highest instantaneous value is written into *pHiwtr. ^If 8095 ** the resetFlg is true, then the highest instantaneous value is 8096 ** reset back down to the current value. 8097 ** 8098 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8099 ** non-zero [error code] on failure. 8100 ** 8101 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8102 */ 8103 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8104 8105 /* 8106 ** CAPI3REF: Status Parameters for database connections 8107 ** KEYWORDS: {SQLITE_DBSTATUS options} 8108 ** 8109 ** These constants are the available integer "verbs" that can be passed as 8110 ** the second argument to the [sqlite3_db_status()] interface. 8111 ** 8112 ** New verbs may be added in future releases of SQLite. Existing verbs 8113 ** might be discontinued. Applications should check the return code from 8114 ** [sqlite3_db_status()] to make sure that the call worked. 8115 ** The [sqlite3_db_status()] interface will return a non-zero error code 8116 ** if a discontinued or unsupported verb is invoked. 8117 ** 8118 ** <dl> 8119 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8120 ** <dd>This parameter returns the number of lookaside memory slots currently 8121 ** checked out.</dd>)^ 8122 ** 8123 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8124 ** <dd>This parameter returns the number of malloc attempts that were 8125 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8126 ** the current value is always zero.)^ 8127 ** 8128 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8129 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8130 ** <dd>This parameter returns the number malloc attempts that might have 8131 ** been satisfied using lookaside memory but failed due to the amount of 8132 ** memory requested being larger than the lookaside slot size. 8133 ** Only the high-water value is meaningful; 8134 ** the current value is always zero.)^ 8135 ** 8136 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8137 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8138 ** <dd>This parameter returns the number malloc attempts that might have 8139 ** been satisfied using lookaside memory but failed due to all lookaside 8140 ** memory already being in use. 8141 ** Only the high-water value is meaningful; 8142 ** the current value is always zero.)^ 8143 ** 8144 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8145 ** <dd>This parameter returns the approximate number of bytes of heap 8146 ** memory used by all pager caches associated with the database connection.)^ 8147 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8148 ** 8149 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8150 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8151 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8152 ** pager cache is shared between two or more connections the bytes of heap 8153 ** memory used by that pager cache is divided evenly between the attached 8154 ** connections.)^ In other words, if none of the pager caches associated 8155 ** with the database connection are shared, this request returns the same 8156 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8157 ** shared, the value returned by this call will be smaller than that returned 8158 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8159 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8160 ** 8161 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8162 ** <dd>This parameter returns the approximate number of bytes of heap 8163 ** memory used to store the schema for all databases associated 8164 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8165 ** ^The full amount of memory used by the schemas is reported, even if the 8166 ** schema memory is shared with other database connections due to 8167 ** [shared cache mode] being enabled. 8168 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8169 ** 8170 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8171 ** <dd>This parameter returns the approximate number of bytes of heap 8172 ** and lookaside memory used by all prepared statements associated with 8173 ** the database connection.)^ 8174 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8175 ** </dd> 8176 ** 8177 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8178 ** <dd>This parameter returns the number of pager cache hits that have 8179 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8180 ** is always 0. 8181 ** </dd> 8182 ** 8183 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8184 ** <dd>This parameter returns the number of pager cache misses that have 8185 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8186 ** is always 0. 8187 ** </dd> 8188 ** 8189 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8190 ** <dd>This parameter returns the number of dirty cache entries that have 8191 ** been written to disk. Specifically, the number of pages written to the 8192 ** wal file in wal mode databases, or the number of pages written to the 8193 ** database file in rollback mode databases. Any pages written as part of 8194 ** transaction rollback or database recovery operations are not included. 8195 ** If an IO or other error occurs while writing a page to disk, the effect 8196 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8197 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8198 ** </dd> 8199 ** 8200 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8201 ** <dd>This parameter returns the number of dirty cache entries that have 8202 ** been written to disk in the middle of a transaction due to the page 8203 ** cache overflowing. Transactions are more efficient if they are written 8204 ** to disk all at once. When pages spill mid-transaction, that introduces 8205 ** additional overhead. This parameter can be used help identify 8206 ** inefficiencies that can be resolved by increasing the cache size. 8207 ** </dd> 8208 ** 8209 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8210 ** <dd>This parameter returns zero for the current value if and only if 8211 ** all foreign key constraints (deferred or immediate) have been 8212 ** resolved.)^ ^The highwater mark is always 0. 8213 ** </dd> 8214 ** </dl> 8215 */ 8216 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8217 #define SQLITE_DBSTATUS_CACHE_USED 1 8218 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8219 #define SQLITE_DBSTATUS_STMT_USED 3 8220 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8221 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8222 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8223 #define SQLITE_DBSTATUS_CACHE_HIT 7 8224 #define SQLITE_DBSTATUS_CACHE_MISS 8 8225 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8226 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8227 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8228 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8229 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8230 8231 8232 /* 8233 ** CAPI3REF: Prepared Statement Status 8234 ** METHOD: sqlite3_stmt 8235 ** 8236 ** ^(Each prepared statement maintains various 8237 ** [SQLITE_STMTSTATUS counters] that measure the number 8238 ** of times it has performed specific operations.)^ These counters can 8239 ** be used to monitor the performance characteristics of the prepared 8240 ** statements. For example, if the number of table steps greatly exceeds 8241 ** the number of table searches or result rows, that would tend to indicate 8242 ** that the prepared statement is using a full table scan rather than 8243 ** an index. 8244 ** 8245 ** ^(This interface is used to retrieve and reset counter values from 8246 ** a [prepared statement]. The first argument is the prepared statement 8247 ** object to be interrogated. The second argument 8248 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8249 ** to be interrogated.)^ 8250 ** ^The current value of the requested counter is returned. 8251 ** ^If the resetFlg is true, then the counter is reset to zero after this 8252 ** interface call returns. 8253 ** 8254 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8255 */ 8256 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8257 8258 /* 8259 ** CAPI3REF: Status Parameters for prepared statements 8260 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8261 ** 8262 ** These preprocessor macros define integer codes that name counter 8263 ** values associated with the [sqlite3_stmt_status()] interface. 8264 ** The meanings of the various counters are as follows: 8265 ** 8266 ** <dl> 8267 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8268 ** <dd>^This is the number of times that SQLite has stepped forward in 8269 ** a table as part of a full table scan. Large numbers for this counter 8270 ** may indicate opportunities for performance improvement through 8271 ** careful use of indices.</dd> 8272 ** 8273 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8274 ** <dd>^This is the number of sort operations that have occurred. 8275 ** A non-zero value in this counter may indicate an opportunity to 8276 ** improvement performance through careful use of indices.</dd> 8277 ** 8278 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8279 ** <dd>^This is the number of rows inserted into transient indices that 8280 ** were created automatically in order to help joins run faster. 8281 ** A non-zero value in this counter may indicate an opportunity to 8282 ** improvement performance by adding permanent indices that do not 8283 ** need to be reinitialized each time the statement is run.</dd> 8284 ** 8285 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8286 ** <dd>^This is the number of virtual machine operations executed 8287 ** by the prepared statement if that number is less than or equal 8288 ** to 2147483647. The number of virtual machine operations can be 8289 ** used as a proxy for the total work done by the prepared statement. 8290 ** If the number of virtual machine operations exceeds 2147483647 8291 ** then the value returned by this statement status code is undefined. 8292 ** 8293 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8294 ** <dd>^This is the number of times that the prepare statement has been 8295 ** automatically regenerated due to schema changes or changes to 8296 ** [bound parameters] that might affect the query plan. 8297 ** 8298 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8299 ** <dd>^This is the number of times that the prepared statement has 8300 ** been run. A single "run" for the purposes of this counter is one 8301 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8302 ** The counter is incremented on the first [sqlite3_step()] call of each 8303 ** cycle. 8304 ** 8305 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8306 ** <dd>^This is the approximate number of bytes of heap memory 8307 ** used to store the prepared statement. ^This value is not actually 8308 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8309 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8310 ** </dd> 8311 ** </dl> 8312 */ 8313 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8314 #define SQLITE_STMTSTATUS_SORT 2 8315 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8316 #define SQLITE_STMTSTATUS_VM_STEP 4 8317 #define SQLITE_STMTSTATUS_REPREPARE 5 8318 #define SQLITE_STMTSTATUS_RUN 6 8319 #define SQLITE_STMTSTATUS_MEMUSED 99 8320 8321 /* 8322 ** CAPI3REF: Custom Page Cache Object 8323 ** 8324 ** The sqlite3_pcache type is opaque. It is implemented by 8325 ** the pluggable module. The SQLite core has no knowledge of 8326 ** its size or internal structure and never deals with the 8327 ** sqlite3_pcache object except by holding and passing pointers 8328 ** to the object. 8329 ** 8330 ** See [sqlite3_pcache_methods2] for additional information. 8331 */ 8332 typedef struct sqlite3_pcache sqlite3_pcache; 8333 8334 /* 8335 ** CAPI3REF: Custom Page Cache Object 8336 ** 8337 ** The sqlite3_pcache_page object represents a single page in the 8338 ** page cache. The page cache will allocate instances of this 8339 ** object. Various methods of the page cache use pointers to instances 8340 ** of this object as parameters or as their return value. 8341 ** 8342 ** See [sqlite3_pcache_methods2] for additional information. 8343 */ 8344 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8345 struct sqlite3_pcache_page { 8346 void *pBuf; /* The content of the page */ 8347 void *pExtra; /* Extra information associated with the page */ 8348 }; 8349 8350 /* 8351 ** CAPI3REF: Application Defined Page Cache. 8352 ** KEYWORDS: {page cache} 8353 ** 8354 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8355 ** register an alternative page cache implementation by passing in an 8356 ** instance of the sqlite3_pcache_methods2 structure.)^ 8357 ** In many applications, most of the heap memory allocated by 8358 ** SQLite is used for the page cache. 8359 ** By implementing a 8360 ** custom page cache using this API, an application can better control 8361 ** the amount of memory consumed by SQLite, the way in which 8362 ** that memory is allocated and released, and the policies used to 8363 ** determine exactly which parts of a database file are cached and for 8364 ** how long. 8365 ** 8366 ** The alternative page cache mechanism is an 8367 ** extreme measure that is only needed by the most demanding applications. 8368 ** The built-in page cache is recommended for most uses. 8369 ** 8370 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8371 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8372 ** the application may discard the parameter after the call to 8373 ** [sqlite3_config()] returns.)^ 8374 ** 8375 ** [[the xInit() page cache method]] 8376 ** ^(The xInit() method is called once for each effective 8377 ** call to [sqlite3_initialize()])^ 8378 ** (usually only once during the lifetime of the process). ^(The xInit() 8379 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8380 ** The intent of the xInit() method is to set up global data structures 8381 ** required by the custom page cache implementation. 8382 ** ^(If the xInit() method is NULL, then the 8383 ** built-in default page cache is used instead of the application defined 8384 ** page cache.)^ 8385 ** 8386 ** [[the xShutdown() page cache method]] 8387 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8388 ** It can be used to clean up 8389 ** any outstanding resources before process shutdown, if required. 8390 ** ^The xShutdown() method may be NULL. 8391 ** 8392 ** ^SQLite automatically serializes calls to the xInit method, 8393 ** so the xInit method need not be threadsafe. ^The 8394 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8395 ** not need to be threadsafe either. All other methods must be threadsafe 8396 ** in multithreaded applications. 8397 ** 8398 ** ^SQLite will never invoke xInit() more than once without an intervening 8399 ** call to xShutdown(). 8400 ** 8401 ** [[the xCreate() page cache methods]] 8402 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8403 ** SQLite will typically create one cache instance for each open database file, 8404 ** though this is not guaranteed. ^The 8405 ** first parameter, szPage, is the size in bytes of the pages that must 8406 ** be allocated by the cache. ^szPage will always a power of two. ^The 8407 ** second parameter szExtra is a number of bytes of extra storage 8408 ** associated with each page cache entry. ^The szExtra parameter will 8409 ** a number less than 250. SQLite will use the 8410 ** extra szExtra bytes on each page to store metadata about the underlying 8411 ** database page on disk. The value passed into szExtra depends 8412 ** on the SQLite version, the target platform, and how SQLite was compiled. 8413 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8414 ** created will be used to cache database pages of a file stored on disk, or 8415 ** false if it is used for an in-memory database. The cache implementation 8416 ** does not have to do anything special based with the value of bPurgeable; 8417 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8418 ** never invoke xUnpin() except to deliberately delete a page. 8419 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8420 ** false will always have the "discard" flag set to true. 8421 ** ^Hence, a cache created with bPurgeable false will 8422 ** never contain any unpinned pages. 8423 ** 8424 ** [[the xCachesize() page cache method]] 8425 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8426 ** suggested maximum cache-size (number of pages stored by) the cache 8427 ** instance passed as the first argument. This is the value configured using 8428 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8429 ** parameter, the implementation is not required to do anything with this 8430 ** value; it is advisory only. 8431 ** 8432 ** [[the xPagecount() page cache methods]] 8433 ** The xPagecount() method must return the number of pages currently 8434 ** stored in the cache, both pinned and unpinned. 8435 ** 8436 ** [[the xFetch() page cache methods]] 8437 ** The xFetch() method locates a page in the cache and returns a pointer to 8438 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8439 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8440 ** pointer to a buffer of szPage bytes used to store the content of a 8441 ** single database page. The pExtra element of sqlite3_pcache_page will be 8442 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8443 ** for each entry in the page cache. 8444 ** 8445 ** The page to be fetched is determined by the key. ^The minimum key value 8446 ** is 1. After it has been retrieved using xFetch, the page is considered 8447 ** to be "pinned". 8448 ** 8449 ** If the requested page is already in the page cache, then the page cache 8450 ** implementation must return a pointer to the page buffer with its content 8451 ** intact. If the requested page is not already in the cache, then the 8452 ** cache implementation should use the value of the createFlag 8453 ** parameter to help it determined what action to take: 8454 ** 8455 ** <table border=1 width=85% align=center> 8456 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8457 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8458 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8459 ** Otherwise return NULL. 8460 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8461 ** NULL if allocating a new page is effectively impossible. 8462 ** </table> 8463 ** 8464 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8465 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8466 ** failed.)^ In between the xFetch() calls, SQLite may 8467 ** attempt to unpin one or more cache pages by spilling the content of 8468 ** pinned pages to disk and synching the operating system disk cache. 8469 ** 8470 ** [[the xUnpin() page cache method]] 8471 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8472 ** as its second argument. If the third parameter, discard, is non-zero, 8473 ** then the page must be evicted from the cache. 8474 ** ^If the discard parameter is 8475 ** zero, then the page may be discarded or retained at the discretion of 8476 ** page cache implementation. ^The page cache implementation 8477 ** may choose to evict unpinned pages at any time. 8478 ** 8479 ** The cache must not perform any reference counting. A single 8480 ** call to xUnpin() unpins the page regardless of the number of prior calls 8481 ** to xFetch(). 8482 ** 8483 ** [[the xRekey() page cache methods]] 8484 ** The xRekey() method is used to change the key value associated with the 8485 ** page passed as the second argument. If the cache 8486 ** previously contains an entry associated with newKey, it must be 8487 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8488 ** to be pinned. 8489 ** 8490 ** When SQLite calls the xTruncate() method, the cache must discard all 8491 ** existing cache entries with page numbers (keys) greater than or equal 8492 ** to the value of the iLimit parameter passed to xTruncate(). If any 8493 ** of these pages are pinned, they are implicitly unpinned, meaning that 8494 ** they can be safely discarded. 8495 ** 8496 ** [[the xDestroy() page cache method]] 8497 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8498 ** All resources associated with the specified cache should be freed. ^After 8499 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8500 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8501 ** functions. 8502 ** 8503 ** [[the xShrink() page cache method]] 8504 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8505 ** free up as much of heap memory as possible. The page cache implementation 8506 ** is not obligated to free any memory, but well-behaved implementations should 8507 ** do their best. 8508 */ 8509 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8510 struct sqlite3_pcache_methods2 { 8511 int iVersion; 8512 void *pArg; 8513 int (*xInit)(void*); 8514 void (*xShutdown)(void*); 8515 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8516 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8517 int (*xPagecount)(sqlite3_pcache*); 8518 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8519 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8520 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8521 unsigned oldKey, unsigned newKey); 8522 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8523 void (*xDestroy)(sqlite3_pcache*); 8524 void (*xShrink)(sqlite3_pcache*); 8525 }; 8526 8527 /* 8528 ** This is the obsolete pcache_methods object that has now been replaced 8529 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8530 ** retained in the header file for backwards compatibility only. 8531 */ 8532 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8533 struct sqlite3_pcache_methods { 8534 void *pArg; 8535 int (*xInit)(void*); 8536 void (*xShutdown)(void*); 8537 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8538 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8539 int (*xPagecount)(sqlite3_pcache*); 8540 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8541 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8542 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8543 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8544 void (*xDestroy)(sqlite3_pcache*); 8545 }; 8546 8547 8548 /* 8549 ** CAPI3REF: Online Backup Object 8550 ** 8551 ** The sqlite3_backup object records state information about an ongoing 8552 ** online backup operation. ^The sqlite3_backup object is created by 8553 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8554 ** [sqlite3_backup_finish()]. 8555 ** 8556 ** See Also: [Using the SQLite Online Backup API] 8557 */ 8558 typedef struct sqlite3_backup sqlite3_backup; 8559 8560 /* 8561 ** CAPI3REF: Online Backup API. 8562 ** 8563 ** The backup API copies the content of one database into another. 8564 ** It is useful either for creating backups of databases or 8565 ** for copying in-memory databases to or from persistent files. 8566 ** 8567 ** See Also: [Using the SQLite Online Backup API] 8568 ** 8569 ** ^SQLite holds a write transaction open on the destination database file 8570 ** for the duration of the backup operation. 8571 ** ^The source database is read-locked only while it is being read; 8572 ** it is not locked continuously for the entire backup operation. 8573 ** ^Thus, the backup may be performed on a live source database without 8574 ** preventing other database connections from 8575 ** reading or writing to the source database while the backup is underway. 8576 ** 8577 ** ^(To perform a backup operation: 8578 ** <ol> 8579 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8580 ** backup, 8581 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8582 ** the data between the two databases, and finally 8583 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8584 ** associated with the backup operation. 8585 ** </ol>)^ 8586 ** There should be exactly one call to sqlite3_backup_finish() for each 8587 ** successful call to sqlite3_backup_init(). 8588 ** 8589 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8590 ** 8591 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8592 ** [database connection] associated with the destination database 8593 ** and the database name, respectively. 8594 ** ^The database name is "main" for the main database, "temp" for the 8595 ** temporary database, or the name specified after the AS keyword in 8596 ** an [ATTACH] statement for an attached database. 8597 ** ^The S and M arguments passed to 8598 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8599 ** and database name of the source database, respectively. 8600 ** ^The source and destination [database connections] (parameters S and D) 8601 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8602 ** an error. 8603 ** 8604 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8605 ** there is already a read or read-write transaction open on the 8606 ** destination database. 8607 ** 8608 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8609 ** returned and an error code and error message are stored in the 8610 ** destination [database connection] D. 8611 ** ^The error code and message for the failed call to sqlite3_backup_init() 8612 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8613 ** [sqlite3_errmsg16()] functions. 8614 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8615 ** [sqlite3_backup] object. 8616 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8617 ** sqlite3_backup_finish() functions to perform the specified backup 8618 ** operation. 8619 ** 8620 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8621 ** 8622 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8623 ** the source and destination databases specified by [sqlite3_backup] object B. 8624 ** ^If N is negative, all remaining source pages are copied. 8625 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8626 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8627 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8628 ** from source to destination, then it returns [SQLITE_DONE]. 8629 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8630 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8631 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8632 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8633 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8634 ** 8635 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8636 ** <ol> 8637 ** <li> the destination database was opened read-only, or 8638 ** <li> the destination database is using write-ahead-log journaling 8639 ** and the destination and source page sizes differ, or 8640 ** <li> the destination database is an in-memory database and the 8641 ** destination and source page sizes differ. 8642 ** </ol>)^ 8643 ** 8644 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8645 ** the [sqlite3_busy_handler | busy-handler function] 8646 ** is invoked (if one is specified). ^If the 8647 ** busy-handler returns non-zero before the lock is available, then 8648 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8649 ** sqlite3_backup_step() can be retried later. ^If the source 8650 ** [database connection] 8651 ** is being used to write to the source database when sqlite3_backup_step() 8652 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8653 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8654 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8655 ** [SQLITE_READONLY] is returned, then 8656 ** there is no point in retrying the call to sqlite3_backup_step(). These 8657 ** errors are considered fatal.)^ The application must accept 8658 ** that the backup operation has failed and pass the backup operation handle 8659 ** to the sqlite3_backup_finish() to release associated resources. 8660 ** 8661 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8662 ** on the destination file. ^The exclusive lock is not released until either 8663 ** sqlite3_backup_finish() is called or the backup operation is complete 8664 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8665 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8666 ** lasts for the duration of the sqlite3_backup_step() call. 8667 ** ^Because the source database is not locked between calls to 8668 ** sqlite3_backup_step(), the source database may be modified mid-way 8669 ** through the backup process. ^If the source database is modified by an 8670 ** external process or via a database connection other than the one being 8671 ** used by the backup operation, then the backup will be automatically 8672 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8673 ** database is modified by the using the same database connection as is used 8674 ** by the backup operation, then the backup database is automatically 8675 ** updated at the same time. 8676 ** 8677 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8678 ** 8679 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8680 ** application wishes to abandon the backup operation, the application 8681 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8682 ** ^The sqlite3_backup_finish() interfaces releases all 8683 ** resources associated with the [sqlite3_backup] object. 8684 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8685 ** active write-transaction on the destination database is rolled back. 8686 ** The [sqlite3_backup] object is invalid 8687 ** and may not be used following a call to sqlite3_backup_finish(). 8688 ** 8689 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8690 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8691 ** sqlite3_backup_step() completed. 8692 ** ^If an out-of-memory condition or IO error occurred during any prior 8693 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8694 ** sqlite3_backup_finish() returns the corresponding [error code]. 8695 ** 8696 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8697 ** is not a permanent error and does not affect the return value of 8698 ** sqlite3_backup_finish(). 8699 ** 8700 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8701 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8702 ** 8703 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8704 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8705 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8706 ** in the source database at the conclusion of the most recent 8707 ** sqlite3_backup_step(). 8708 ** ^(The values returned by these functions are only updated by 8709 ** sqlite3_backup_step(). If the source database is modified in a way that 8710 ** changes the size of the source database or the number of pages remaining, 8711 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8712 ** and sqlite3_backup_remaining() until after the next 8713 ** sqlite3_backup_step().)^ 8714 ** 8715 ** <b>Concurrent Usage of Database Handles</b> 8716 ** 8717 ** ^The source [database connection] may be used by the application for other 8718 ** purposes while a backup operation is underway or being initialized. 8719 ** ^If SQLite is compiled and configured to support threadsafe database 8720 ** connections, then the source database connection may be used concurrently 8721 ** from within other threads. 8722 ** 8723 ** However, the application must guarantee that the destination 8724 ** [database connection] is not passed to any other API (by any thread) after 8725 ** sqlite3_backup_init() is called and before the corresponding call to 8726 ** sqlite3_backup_finish(). SQLite does not currently check to see 8727 ** if the application incorrectly accesses the destination [database connection] 8728 ** and so no error code is reported, but the operations may malfunction 8729 ** nevertheless. Use of the destination database connection while a 8730 ** backup is in progress might also also cause a mutex deadlock. 8731 ** 8732 ** If running in [shared cache mode], the application must 8733 ** guarantee that the shared cache used by the destination database 8734 ** is not accessed while the backup is running. In practice this means 8735 ** that the application must guarantee that the disk file being 8736 ** backed up to is not accessed by any connection within the process, 8737 ** not just the specific connection that was passed to sqlite3_backup_init(). 8738 ** 8739 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8740 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8741 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8742 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8743 ** same time as another thread is invoking sqlite3_backup_step() it is 8744 ** possible that they return invalid values. 8745 */ 8746 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8747 sqlite3 *pDest, /* Destination database handle */ 8748 const char *zDestName, /* Destination database name */ 8749 sqlite3 *pSource, /* Source database handle */ 8750 const char *zSourceName /* Source database name */ 8751 ); 8752 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8753 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8754 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8755 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8756 8757 /* 8758 ** CAPI3REF: Unlock Notification 8759 ** METHOD: sqlite3 8760 ** 8761 ** ^When running in shared-cache mode, a database operation may fail with 8762 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8763 ** individual tables within the shared-cache cannot be obtained. See 8764 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8765 ** ^This API may be used to register a callback that SQLite will invoke 8766 ** when the connection currently holding the required lock relinquishes it. 8767 ** ^This API is only available if the library was compiled with the 8768 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8769 ** 8770 ** See Also: [Using the SQLite Unlock Notification Feature]. 8771 ** 8772 ** ^Shared-cache locks are released when a database connection concludes 8773 ** its current transaction, either by committing it or rolling it back. 8774 ** 8775 ** ^When a connection (known as the blocked connection) fails to obtain a 8776 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8777 ** identity of the database connection (the blocking connection) that 8778 ** has locked the required resource is stored internally. ^After an 8779 ** application receives an SQLITE_LOCKED error, it may call the 8780 ** sqlite3_unlock_notify() method with the blocked connection handle as 8781 ** the first argument to register for a callback that will be invoked 8782 ** when the blocking connections current transaction is concluded. ^The 8783 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8784 ** call that concludes the blocking connection's transaction. 8785 ** 8786 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8787 ** there is a chance that the blocking connection will have already 8788 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8789 ** If this happens, then the specified callback is invoked immediately, 8790 ** from within the call to sqlite3_unlock_notify().)^ 8791 ** 8792 ** ^If the blocked connection is attempting to obtain a write-lock on a 8793 ** shared-cache table, and more than one other connection currently holds 8794 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8795 ** the other connections to use as the blocking connection. 8796 ** 8797 ** ^(There may be at most one unlock-notify callback registered by a 8798 ** blocked connection. If sqlite3_unlock_notify() is called when the 8799 ** blocked connection already has a registered unlock-notify callback, 8800 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8801 ** called with a NULL pointer as its second argument, then any existing 8802 ** unlock-notify callback is canceled. ^The blocked connections 8803 ** unlock-notify callback may also be canceled by closing the blocked 8804 ** connection using [sqlite3_close()]. 8805 ** 8806 ** The unlock-notify callback is not reentrant. If an application invokes 8807 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8808 ** crash or deadlock may be the result. 8809 ** 8810 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8811 ** returns SQLITE_OK. 8812 ** 8813 ** <b>Callback Invocation Details</b> 8814 ** 8815 ** When an unlock-notify callback is registered, the application provides a 8816 ** single void* pointer that is passed to the callback when it is invoked. 8817 ** However, the signature of the callback function allows SQLite to pass 8818 ** it an array of void* context pointers. The first argument passed to 8819 ** an unlock-notify callback is a pointer to an array of void* pointers, 8820 ** and the second is the number of entries in the array. 8821 ** 8822 ** When a blocking connection's transaction is concluded, there may be 8823 ** more than one blocked connection that has registered for an unlock-notify 8824 ** callback. ^If two or more such blocked connections have specified the 8825 ** same callback function, then instead of invoking the callback function 8826 ** multiple times, it is invoked once with the set of void* context pointers 8827 ** specified by the blocked connections bundled together into an array. 8828 ** This gives the application an opportunity to prioritize any actions 8829 ** related to the set of unblocked database connections. 8830 ** 8831 ** <b>Deadlock Detection</b> 8832 ** 8833 ** Assuming that after registering for an unlock-notify callback a 8834 ** database waits for the callback to be issued before taking any further 8835 ** action (a reasonable assumption), then using this API may cause the 8836 ** application to deadlock. For example, if connection X is waiting for 8837 ** connection Y's transaction to be concluded, and similarly connection 8838 ** Y is waiting on connection X's transaction, then neither connection 8839 ** will proceed and the system may remain deadlocked indefinitely. 8840 ** 8841 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8842 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8843 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8844 ** unlock-notify callback is registered. The system is said to be in 8845 ** a deadlocked state if connection A has registered for an unlock-notify 8846 ** callback on the conclusion of connection B's transaction, and connection 8847 ** B has itself registered for an unlock-notify callback when connection 8848 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8849 ** the system is also considered to be deadlocked if connection B has 8850 ** registered for an unlock-notify callback on the conclusion of connection 8851 ** C's transaction, where connection C is waiting on connection A. ^Any 8852 ** number of levels of indirection are allowed. 8853 ** 8854 ** <b>The "DROP TABLE" Exception</b> 8855 ** 8856 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8857 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8858 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8859 ** SQLite checks if there are any currently executing SELECT statements 8860 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8861 ** returned. In this case there is no "blocking connection", so invoking 8862 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8863 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8864 ** or "DROP INDEX" query, an infinite loop might be the result. 8865 ** 8866 ** One way around this problem is to check the extended error code returned 8867 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8868 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8869 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8870 ** SQLITE_LOCKED.)^ 8871 */ 8872 SQLITE_API int sqlite3_unlock_notify( 8873 sqlite3 *pBlocked, /* Waiting connection */ 8874 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8875 void *pNotifyArg /* Argument to pass to xNotify */ 8876 ); 8877 8878 8879 /* 8880 ** CAPI3REF: String Comparison 8881 ** 8882 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8883 ** and extensions to compare the contents of two buffers containing UTF-8 8884 ** strings in a case-independent fashion, using the same definition of "case 8885 ** independence" that SQLite uses internally when comparing identifiers. 8886 */ 8887 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8888 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8889 8890 /* 8891 ** CAPI3REF: String Globbing 8892 * 8893 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8894 ** string X matches the [GLOB] pattern P. 8895 ** ^The definition of [GLOB] pattern matching used in 8896 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8897 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8898 ** is case sensitive. 8899 ** 8900 ** Note that this routine returns zero on a match and non-zero if the strings 8901 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8902 ** 8903 ** See also: [sqlite3_strlike()]. 8904 */ 8905 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8906 8907 /* 8908 ** CAPI3REF: String LIKE Matching 8909 * 8910 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8911 ** string X matches the [LIKE] pattern P with escape character E. 8912 ** ^The definition of [LIKE] pattern matching used in 8913 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8914 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8915 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8916 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8917 ** insensitive - equivalent upper and lower case ASCII characters match 8918 ** one another. 8919 ** 8920 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8921 ** only ASCII characters are case folded. 8922 ** 8923 ** Note that this routine returns zero on a match and non-zero if the strings 8924 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8925 ** 8926 ** See also: [sqlite3_strglob()]. 8927 */ 8928 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8929 8930 /* 8931 ** CAPI3REF: Error Logging Interface 8932 ** 8933 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8934 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8935 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8936 ** used with [sqlite3_snprintf()] to generate the final output string. 8937 ** 8938 ** The sqlite3_log() interface is intended for use by extensions such as 8939 ** virtual tables, collating functions, and SQL functions. While there is 8940 ** nothing to prevent an application from calling sqlite3_log(), doing so 8941 ** is considered bad form. 8942 ** 8943 ** The zFormat string must not be NULL. 8944 ** 8945 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8946 ** will not use dynamically allocated memory. The log message is stored in 8947 ** a fixed-length buffer on the stack. If the log message is longer than 8948 ** a few hundred characters, it will be truncated to the length of the 8949 ** buffer. 8950 */ 8951 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8952 8953 /* 8954 ** CAPI3REF: Write-Ahead Log Commit Hook 8955 ** METHOD: sqlite3 8956 ** 8957 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8958 ** is invoked each time data is committed to a database in wal mode. 8959 ** 8960 ** ^(The callback is invoked by SQLite after the commit has taken place and 8961 ** the associated write-lock on the database released)^, so the implementation 8962 ** may read, write or [checkpoint] the database as required. 8963 ** 8964 ** ^The first parameter passed to the callback function when it is invoked 8965 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8966 ** registering the callback. ^The second is a copy of the database handle. 8967 ** ^The third parameter is the name of the database that was written to - 8968 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8969 ** is the number of pages currently in the write-ahead log file, 8970 ** including those that were just committed. 8971 ** 8972 ** The callback function should normally return [SQLITE_OK]. ^If an error 8973 ** code is returned, that error will propagate back up through the 8974 ** SQLite code base to cause the statement that provoked the callback 8975 ** to report an error, though the commit will have still occurred. If the 8976 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8977 ** that does not correspond to any valid SQLite error code, the results 8978 ** are undefined. 8979 ** 8980 ** A single database handle may have at most a single write-ahead log callback 8981 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8982 ** previously registered write-ahead log callback. ^Note that the 8983 ** [sqlite3_wal_autocheckpoint()] interface and the 8984 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8985 ** overwrite any prior [sqlite3_wal_hook()] settings. 8986 */ 8987 SQLITE_API void *sqlite3_wal_hook( 8988 sqlite3*, 8989 int(*)(void *,sqlite3*,const char*,int), 8990 void* 8991 ); 8992 8993 /* 8994 ** CAPI3REF: Configure an auto-checkpoint 8995 ** METHOD: sqlite3 8996 ** 8997 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8998 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8999 ** to automatically [checkpoint] 9000 ** after committing a transaction if there are N or 9001 ** more frames in the [write-ahead log] file. ^Passing zero or 9002 ** a negative value as the nFrame parameter disables automatic 9003 ** checkpoints entirely. 9004 ** 9005 ** ^The callback registered by this function replaces any existing callback 9006 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9007 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9008 ** configured by this function. 9009 ** 9010 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9011 ** from SQL. 9012 ** 9013 ** ^Checkpoints initiated by this mechanism are 9014 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9015 ** 9016 ** ^Every new [database connection] defaults to having the auto-checkpoint 9017 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9018 ** pages. The use of this interface 9019 ** is only necessary if the default setting is found to be suboptimal 9020 ** for a particular application. 9021 */ 9022 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9023 9024 /* 9025 ** CAPI3REF: Checkpoint a database 9026 ** METHOD: sqlite3 9027 ** 9028 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9029 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9030 ** 9031 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9032 ** [write-ahead log] for database X on [database connection] D to be 9033 ** transferred into the database file and for the write-ahead log to 9034 ** be reset. See the [checkpointing] documentation for addition 9035 ** information. 9036 ** 9037 ** This interface used to be the only way to cause a checkpoint to 9038 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9039 ** interface was added. This interface is retained for backwards 9040 ** compatibility and as a convenience for applications that need to manually 9041 ** start a callback but which do not need the full power (and corresponding 9042 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9043 */ 9044 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9045 9046 /* 9047 ** CAPI3REF: Checkpoint a database 9048 ** METHOD: sqlite3 9049 ** 9050 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9051 ** operation on database X of [database connection] D in mode M. Status 9052 ** information is written back into integers pointed to by L and C.)^ 9053 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9054 ** 9055 ** <dl> 9056 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9057 ** ^Checkpoint as many frames as possible without waiting for any database 9058 ** readers or writers to finish, then sync the database file if all frames 9059 ** in the log were checkpointed. ^The [busy-handler callback] 9060 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9061 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9062 ** if there are concurrent readers or writers. 9063 ** 9064 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9065 ** ^This mode blocks (it invokes the 9066 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9067 ** database writer and all readers are reading from the most recent database 9068 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9069 ** database file. ^This mode blocks new database writers while it is pending, 9070 ** but new database readers are allowed to continue unimpeded. 9071 ** 9072 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9073 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9074 ** that after checkpointing the log file it blocks (calls the 9075 ** [busy-handler callback]) 9076 ** until all readers are reading from the database file only. ^This ensures 9077 ** that the next writer will restart the log file from the beginning. 9078 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9079 ** database writer attempts while it is pending, but does not impede readers. 9080 ** 9081 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9082 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9083 ** addition that it also truncates the log file to zero bytes just prior 9084 ** to a successful return. 9085 ** </dl> 9086 ** 9087 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9088 ** the log file or to -1 if the checkpoint could not run because 9089 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9090 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9091 ** log file (including any that were already checkpointed before the function 9092 ** was called) or to -1 if the checkpoint could not run due to an error or 9093 ** because the database is not in WAL mode. ^Note that upon successful 9094 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9095 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9096 ** 9097 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9098 ** any other process is running a checkpoint operation at the same time, the 9099 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9100 ** busy-handler configured, it will not be invoked in this case. 9101 ** 9102 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9103 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9104 ** obtained immediately, and a busy-handler is configured, it is invoked and 9105 ** the writer lock retried until either the busy-handler returns 0 or the lock 9106 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9107 ** database readers as described above. ^If the busy-handler returns 0 before 9108 ** the writer lock is obtained or while waiting for database readers, the 9109 ** checkpoint operation proceeds from that point in the same way as 9110 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9111 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9112 ** 9113 ** ^If parameter zDb is NULL or points to a zero length string, then the 9114 ** specified operation is attempted on all WAL databases [attached] to 9115 ** [database connection] db. In this case the 9116 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9117 ** an SQLITE_BUSY error is encountered when processing one or more of the 9118 ** attached WAL databases, the operation is still attempted on any remaining 9119 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9120 ** error occurs while processing an attached database, processing is abandoned 9121 ** and the error code is returned to the caller immediately. ^If no error 9122 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9123 ** databases, SQLITE_OK is returned. 9124 ** 9125 ** ^If database zDb is the name of an attached database that is not in WAL 9126 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9127 ** zDb is not NULL (or a zero length string) and is not the name of any 9128 ** attached database, SQLITE_ERROR is returned to the caller. 9129 ** 9130 ** ^Unless it returns SQLITE_MISUSE, 9131 ** the sqlite3_wal_checkpoint_v2() interface 9132 ** sets the error information that is queried by 9133 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9134 ** 9135 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9136 ** from SQL. 9137 */ 9138 SQLITE_API int sqlite3_wal_checkpoint_v2( 9139 sqlite3 *db, /* Database handle */ 9140 const char *zDb, /* Name of attached database (or NULL) */ 9141 int eMode, /* SQLITE_CHECKPOINT_* value */ 9142 int *pnLog, /* OUT: Size of WAL log in frames */ 9143 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9144 ); 9145 9146 /* 9147 ** CAPI3REF: Checkpoint Mode Values 9148 ** KEYWORDS: {checkpoint mode} 9149 ** 9150 ** These constants define all valid values for the "checkpoint mode" passed 9151 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9152 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9153 ** meaning of each of these checkpoint modes. 9154 */ 9155 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9156 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9157 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9158 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9159 9160 /* 9161 ** CAPI3REF: Virtual Table Interface Configuration 9162 ** 9163 ** This function may be called by either the [xConnect] or [xCreate] method 9164 ** of a [virtual table] implementation to configure 9165 ** various facets of the virtual table interface. 9166 ** 9167 ** If this interface is invoked outside the context of an xConnect or 9168 ** xCreate virtual table method then the behavior is undefined. 9169 ** 9170 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9171 ** [database connection] in which the virtual table is being created and 9172 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9173 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9174 ** of the [virtual table configuration options]. The presence and meaning 9175 ** of parameters after C depend on which [virtual table configuration option] 9176 ** is used. 9177 */ 9178 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9179 9180 /* 9181 ** CAPI3REF: Virtual Table Configuration Options 9182 ** KEYWORDS: {virtual table configuration options} 9183 ** KEYWORDS: {virtual table configuration option} 9184 ** 9185 ** These macros define the various options to the 9186 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9187 ** can use to customize and optimize their behavior. 9188 ** 9189 ** <dl> 9190 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9191 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9192 ** <dd>Calls of the form 9193 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9194 ** where X is an integer. If X is zero, then the [virtual table] whose 9195 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9196 ** support constraints. In this configuration (which is the default) if 9197 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9198 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9199 ** specified as part of the users SQL statement, regardless of the actual 9200 ** ON CONFLICT mode specified. 9201 ** 9202 ** If X is non-zero, then the virtual table implementation guarantees 9203 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9204 ** any modifications to internal or persistent data structures have been made. 9205 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9206 ** is able to roll back a statement or database transaction, and abandon 9207 ** or continue processing the current SQL statement as appropriate. 9208 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9209 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9210 ** had been ABORT. 9211 ** 9212 ** Virtual table implementations that are required to handle OR REPLACE 9213 ** must do so within the [xUpdate] method. If a call to the 9214 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9215 ** CONFLICT policy is REPLACE, the virtual table implementation should 9216 ** silently replace the appropriate rows within the xUpdate callback and 9217 ** return SQLITE_OK. Or, if this is not possible, it may return 9218 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9219 ** constraint handling. 9220 ** </dd> 9221 ** 9222 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9223 ** <dd>Calls of the form 9224 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9225 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9226 ** prohibits that virtual table from being used from within triggers and 9227 ** views. 9228 ** </dd> 9229 ** 9230 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9231 ** <dd>Calls of the form 9232 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9233 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9234 ** identify that virtual table as being safe to use from within triggers 9235 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9236 ** virtual table can do no serious harm even if it is controlled by a 9237 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9238 ** flag unless absolutely necessary. 9239 ** </dd> 9240 ** </dl> 9241 */ 9242 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9243 #define SQLITE_VTAB_INNOCUOUS 2 9244 #define SQLITE_VTAB_DIRECTONLY 3 9245 9246 /* 9247 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9248 ** 9249 ** This function may only be called from within a call to the [xUpdate] method 9250 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9251 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9252 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9253 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9254 ** [virtual table]. 9255 */ 9256 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9257 9258 /* 9259 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9260 ** 9261 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9262 ** method of a [virtual table], then it might return true if the 9263 ** column is being fetched as part of an UPDATE operation during which the 9264 ** column value will not change. The virtual table implementation can use 9265 ** this hint as permission to substitute a return value that is less 9266 ** expensive to compute and that the corresponding 9267 ** [xUpdate] method understands as a "no-change" value. 9268 ** 9269 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9270 ** the column is not changed by the UPDATE statement, then the xColumn 9271 ** method can optionally return without setting a result, without calling 9272 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9273 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9274 ** same column in the [xUpdate] method. 9275 ** 9276 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9277 ** implementations should continue to give a correct answer even if the 9278 ** sqlite3_vtab_nochange() interface were to always return false. In the 9279 ** current implementation, the sqlite3_vtab_nochange() interface does always 9280 ** returns false for the enhanced [UPDATE FROM] statement. 9281 */ 9282 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9283 9284 /* 9285 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9286 ** 9287 ** This function may only be called from within a call to the [xBestIndex] 9288 ** method of a [virtual table]. 9289 ** 9290 ** The first argument must be the sqlite3_index_info object that is the 9291 ** first parameter to the xBestIndex() method. The second argument must be 9292 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 9293 ** structure passed to xBestIndex. This function returns a pointer to a buffer 9294 ** containing the name of the collation sequence for the corresponding 9295 ** constraint. 9296 */ 9297 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9298 9299 /* 9300 ** CAPI3REF: Conflict resolution modes 9301 ** KEYWORDS: {conflict resolution mode} 9302 ** 9303 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9304 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9305 ** is for the SQL statement being evaluated. 9306 ** 9307 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9308 ** return value from the [sqlite3_set_authorizer()] callback and that 9309 ** [SQLITE_ABORT] is also a [result code]. 9310 */ 9311 #define SQLITE_ROLLBACK 1 9312 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9313 #define SQLITE_FAIL 3 9314 /* #define SQLITE_ABORT 4 // Also an error code */ 9315 #define SQLITE_REPLACE 5 9316 9317 /* 9318 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9319 ** KEYWORDS: {scanstatus options} 9320 ** 9321 ** The following constants can be used for the T parameter to the 9322 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9323 ** different metric for sqlite3_stmt_scanstatus() to return. 9324 ** 9325 ** When the value returned to V is a string, space to hold that string is 9326 ** managed by the prepared statement S and will be automatically freed when 9327 ** S is finalized. 9328 ** 9329 ** <dl> 9330 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9331 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9332 ** set to the total number of times that the X-th loop has run.</dd> 9333 ** 9334 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9335 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9336 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9337 ** 9338 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9339 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9340 ** query planner's estimate for the average number of rows output from each 9341 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9342 ** then this value will approximate the quotient NVISIT/NLOOP and the 9343 ** product of this value for all prior loops with the same SELECTID will 9344 ** be the NLOOP value for the current loop. 9345 ** 9346 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9347 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9348 ** to a zero-terminated UTF-8 string containing the name of the index or table 9349 ** used for the X-th loop. 9350 ** 9351 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9352 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9353 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9354 ** description for the X-th loop. 9355 ** 9356 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9357 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9358 ** "select-id" for the X-th loop. The select-id identifies which query or 9359 ** subquery the loop is part of. The main query has a select-id of zero. 9360 ** The select-id is the same value as is output in the first column 9361 ** of an [EXPLAIN QUERY PLAN] query. 9362 ** </dl> 9363 */ 9364 #define SQLITE_SCANSTAT_NLOOP 0 9365 #define SQLITE_SCANSTAT_NVISIT 1 9366 #define SQLITE_SCANSTAT_EST 2 9367 #define SQLITE_SCANSTAT_NAME 3 9368 #define SQLITE_SCANSTAT_EXPLAIN 4 9369 #define SQLITE_SCANSTAT_SELECTID 5 9370 9371 /* 9372 ** CAPI3REF: Prepared Statement Scan Status 9373 ** METHOD: sqlite3_stmt 9374 ** 9375 ** This interface returns information about the predicted and measured 9376 ** performance for pStmt. Advanced applications can use this 9377 ** interface to compare the predicted and the measured performance and 9378 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9379 ** 9380 ** Since this interface is expected to be rarely used, it is only 9381 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9382 ** compile-time option. 9383 ** 9384 ** The "iScanStatusOp" parameter determines which status information to return. 9385 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9386 ** of this interface is undefined. 9387 ** ^The requested measurement is written into a variable pointed to by 9388 ** the "pOut" parameter. 9389 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9390 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9391 ** zero or greater than or equal to the total number of loops used to implement 9392 ** the statement - a non-zero value is returned and the variable that pOut 9393 ** points to is unchanged. 9394 ** 9395 ** ^Statistics might not be available for all loops in all statements. ^In cases 9396 ** where there exist loops with no available statistics, this function behaves 9397 ** as if the loop did not exist - it returns non-zero and leave the variable 9398 ** that pOut points to unchanged. 9399 ** 9400 ** See also: [sqlite3_stmt_scanstatus_reset()] 9401 */ 9402 SQLITE_API int sqlite3_stmt_scanstatus( 9403 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9404 int idx, /* Index of loop to report on */ 9405 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9406 void *pOut /* Result written here */ 9407 ); 9408 9409 /* 9410 ** CAPI3REF: Zero Scan-Status Counters 9411 ** METHOD: sqlite3_stmt 9412 ** 9413 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9414 ** 9415 ** This API is only available if the library is built with pre-processor 9416 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9417 */ 9418 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9419 9420 /* 9421 ** CAPI3REF: Flush caches to disk mid-transaction 9422 ** METHOD: sqlite3 9423 ** 9424 ** ^If a write-transaction is open on [database connection] D when the 9425 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9426 ** pages in the pager-cache that are not currently in use are written out 9427 ** to disk. A dirty page may be in use if a database cursor created by an 9428 ** active SQL statement is reading from it, or if it is page 1 of a database 9429 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9430 ** interface flushes caches for all schemas - "main", "temp", and 9431 ** any [attached] databases. 9432 ** 9433 ** ^If this function needs to obtain extra database locks before dirty pages 9434 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9435 ** immediately and there is a busy-handler callback configured, it is invoked 9436 ** in the usual manner. ^If the required lock still cannot be obtained, then 9437 ** the database is skipped and an attempt made to flush any dirty pages 9438 ** belonging to the next (if any) database. ^If any databases are skipped 9439 ** because locks cannot be obtained, but no other error occurs, this 9440 ** function returns SQLITE_BUSY. 9441 ** 9442 ** ^If any other error occurs while flushing dirty pages to disk (for 9443 ** example an IO error or out-of-memory condition), then processing is 9444 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9445 ** 9446 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9447 ** 9448 ** ^This function does not set the database handle error code or message 9449 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9450 */ 9451 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9452 9453 /* 9454 ** CAPI3REF: The pre-update hook. 9455 ** METHOD: sqlite3 9456 ** 9457 ** ^These interfaces are only available if SQLite is compiled using the 9458 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9459 ** 9460 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9461 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9462 ** on a database table. 9463 ** ^At most one preupdate hook may be registered at a time on a single 9464 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9465 ** the previous setting. 9466 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9467 ** with a NULL pointer as the second parameter. 9468 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9469 ** the first parameter to callbacks. 9470 ** 9471 ** ^The preupdate hook only fires for changes to real database tables; the 9472 ** preupdate hook is not invoked for changes to [virtual tables] or to 9473 ** system tables like sqlite_sequence or sqlite_stat1. 9474 ** 9475 ** ^The second parameter to the preupdate callback is a pointer to 9476 ** the [database connection] that registered the preupdate hook. 9477 ** ^The third parameter to the preupdate callback is one of the constants 9478 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9479 ** kind of update operation that is about to occur. 9480 ** ^(The fourth parameter to the preupdate callback is the name of the 9481 ** database within the database connection that is being modified. This 9482 ** will be "main" for the main database or "temp" for TEMP tables or 9483 ** the name given after the AS keyword in the [ATTACH] statement for attached 9484 ** databases.)^ 9485 ** ^The fifth parameter to the preupdate callback is the name of the 9486 ** table that is being modified. 9487 ** 9488 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9489 ** parameter passed to the preupdate callback is the initial [rowid] of the 9490 ** row being modified or deleted. For an INSERT operation on a rowid table, 9491 ** or any operation on a WITHOUT ROWID table, the value of the sixth 9492 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9493 ** seventh parameter is the final rowid value of the row being inserted 9494 ** or updated. The value of the seventh parameter passed to the callback 9495 ** function is not defined for operations on WITHOUT ROWID tables, or for 9496 ** DELETE operations on rowid tables. 9497 ** 9498 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9499 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9500 ** provide additional information about a preupdate event. These routines 9501 ** may only be called from within a preupdate callback. Invoking any of 9502 ** these routines from outside of a preupdate callback or with a 9503 ** [database connection] pointer that is different from the one supplied 9504 ** to the preupdate callback results in undefined and probably undesirable 9505 ** behavior. 9506 ** 9507 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9508 ** in the row that is being inserted, updated, or deleted. 9509 ** 9510 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9511 ** a [protected sqlite3_value] that contains the value of the Nth column of 9512 ** the table row before it is updated. The N parameter must be between 0 9513 ** and one less than the number of columns or the behavior will be 9514 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9515 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9516 ** behavior is undefined. The [sqlite3_value] that P points to 9517 ** will be destroyed when the preupdate callback returns. 9518 ** 9519 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9520 ** a [protected sqlite3_value] that contains the value of the Nth column of 9521 ** the table row after it is updated. The N parameter must be between 0 9522 ** and one less than the number of columns or the behavior will be 9523 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9524 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9525 ** behavior is undefined. The [sqlite3_value] that P points to 9526 ** will be destroyed when the preupdate callback returns. 9527 ** 9528 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9529 ** callback was invoked as a result of a direct insert, update, or delete 9530 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9531 ** triggers; or 2 for changes resulting from triggers called by top-level 9532 ** triggers; and so forth. 9533 ** 9534 ** See also: [sqlite3_update_hook()] 9535 */ 9536 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9537 SQLITE_API void *sqlite3_preupdate_hook( 9538 sqlite3 *db, 9539 void(*xPreUpdate)( 9540 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9541 sqlite3 *db, /* Database handle */ 9542 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9543 char const *zDb, /* Database name */ 9544 char const *zName, /* Table name */ 9545 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9546 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9547 ), 9548 void* 9549 ); 9550 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9551 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9552 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9553 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9554 #endif 9555 9556 /* 9557 ** CAPI3REF: Low-level system error code 9558 ** METHOD: sqlite3 9559 ** 9560 ** ^Attempt to return the underlying operating system error code or error 9561 ** number that caused the most recent I/O error or failure to open a file. 9562 ** The return value is OS-dependent. For example, on unix systems, after 9563 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9564 ** called to get back the underlying "errno" that caused the problem, such 9565 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9566 */ 9567 SQLITE_API int sqlite3_system_errno(sqlite3*); 9568 9569 /* 9570 ** CAPI3REF: Database Snapshot 9571 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9572 ** 9573 ** An instance of the snapshot object records the state of a [WAL mode] 9574 ** database for some specific point in history. 9575 ** 9576 ** In [WAL mode], multiple [database connections] that are open on the 9577 ** same database file can each be reading a different historical version 9578 ** of the database file. When a [database connection] begins a read 9579 ** transaction, that connection sees an unchanging copy of the database 9580 ** as it existed for the point in time when the transaction first started. 9581 ** Subsequent changes to the database from other connections are not seen 9582 ** by the reader until a new read transaction is started. 9583 ** 9584 ** The sqlite3_snapshot object records state information about an historical 9585 ** version of the database file so that it is possible to later open a new read 9586 ** transaction that sees that historical version of the database rather than 9587 ** the most recent version. 9588 */ 9589 typedef struct sqlite3_snapshot { 9590 unsigned char hidden[48]; 9591 } sqlite3_snapshot; 9592 9593 /* 9594 ** CAPI3REF: Record A Database Snapshot 9595 ** CONSTRUCTOR: sqlite3_snapshot 9596 ** 9597 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9598 ** new [sqlite3_snapshot] object that records the current state of 9599 ** schema S in database connection D. ^On success, the 9600 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9601 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9602 ** If there is not already a read-transaction open on schema S when 9603 ** this function is called, one is opened automatically. 9604 ** 9605 ** The following must be true for this function to succeed. If any of 9606 ** the following statements are false when sqlite3_snapshot_get() is 9607 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9608 ** in this case. 9609 ** 9610 ** <ul> 9611 ** <li> The database handle must not be in [autocommit mode]. 9612 ** 9613 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9614 ** 9615 ** <li> There must not be a write transaction open on schema S of database 9616 ** connection D. 9617 ** 9618 ** <li> One or more transactions must have been written to the current wal 9619 ** file since it was created on disk (by any connection). This means 9620 ** that a snapshot cannot be taken on a wal mode database with no wal 9621 ** file immediately after it is first opened. At least one transaction 9622 ** must be written to it first. 9623 ** </ul> 9624 ** 9625 ** This function may also return SQLITE_NOMEM. If it is called with the 9626 ** database handle in autocommit mode but fails for some other reason, 9627 ** whether or not a read transaction is opened on schema S is undefined. 9628 ** 9629 ** The [sqlite3_snapshot] object returned from a successful call to 9630 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9631 ** to avoid a memory leak. 9632 ** 9633 ** The [sqlite3_snapshot_get()] interface is only available when the 9634 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9635 */ 9636 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9637 sqlite3 *db, 9638 const char *zSchema, 9639 sqlite3_snapshot **ppSnapshot 9640 ); 9641 9642 /* 9643 ** CAPI3REF: Start a read transaction on an historical snapshot 9644 ** METHOD: sqlite3_snapshot 9645 ** 9646 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9647 ** transaction or upgrades an existing one for schema S of 9648 ** [database connection] D such that the read transaction refers to 9649 ** historical [snapshot] P, rather than the most recent change to the 9650 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9651 ** on success or an appropriate [error code] if it fails. 9652 ** 9653 ** ^In order to succeed, the database connection must not be in 9654 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9655 ** is already a read transaction open on schema S, then the database handle 9656 ** must have no active statements (SELECT statements that have been passed 9657 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9658 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9659 ** if schema S does not exist, or if the snapshot object is invalid. 9660 ** 9661 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9662 ** snapshot has been overwritten by a [checkpoint]. In this case 9663 ** SQLITE_ERROR_SNAPSHOT is returned. 9664 ** 9665 ** If there is already a read transaction open when this function is 9666 ** invoked, then the same read transaction remains open (on the same 9667 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9668 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9669 ** SQLITE_IOERR error code - is returned, then the final state of the 9670 ** read transaction is undefined. If SQLITE_OK is returned, then the 9671 ** read transaction is now open on database snapshot P. 9672 ** 9673 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9674 ** database connection D does not know that the database file for 9675 ** schema S is in [WAL mode]. A database connection might not know 9676 ** that the database file is in [WAL mode] if there has been no prior 9677 ** I/O on that database connection, or if the database entered [WAL mode] 9678 ** after the most recent I/O on the database connection.)^ 9679 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9680 ** database connection in order to make it ready to use snapshots.) 9681 ** 9682 ** The [sqlite3_snapshot_open()] interface is only available when the 9683 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9684 */ 9685 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9686 sqlite3 *db, 9687 const char *zSchema, 9688 sqlite3_snapshot *pSnapshot 9689 ); 9690 9691 /* 9692 ** CAPI3REF: Destroy a snapshot 9693 ** DESTRUCTOR: sqlite3_snapshot 9694 ** 9695 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9696 ** The application must eventually free every [sqlite3_snapshot] object 9697 ** using this routine to avoid a memory leak. 9698 ** 9699 ** The [sqlite3_snapshot_free()] interface is only available when the 9700 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9701 */ 9702 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9703 9704 /* 9705 ** CAPI3REF: Compare the ages of two snapshot handles. 9706 ** METHOD: sqlite3_snapshot 9707 ** 9708 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9709 ** of two valid snapshot handles. 9710 ** 9711 ** If the two snapshot handles are not associated with the same database 9712 ** file, the result of the comparison is undefined. 9713 ** 9714 ** Additionally, the result of the comparison is only valid if both of the 9715 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9716 ** last time the wal file was deleted. The wal file is deleted when the 9717 ** database is changed back to rollback mode or when the number of database 9718 ** clients drops to zero. If either snapshot handle was obtained before the 9719 ** wal file was last deleted, the value returned by this function 9720 ** is undefined. 9721 ** 9722 ** Otherwise, this API returns a negative value if P1 refers to an older 9723 ** snapshot than P2, zero if the two handles refer to the same database 9724 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9725 ** 9726 ** This interface is only available if SQLite is compiled with the 9727 ** [SQLITE_ENABLE_SNAPSHOT] option. 9728 */ 9729 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9730 sqlite3_snapshot *p1, 9731 sqlite3_snapshot *p2 9732 ); 9733 9734 /* 9735 ** CAPI3REF: Recover snapshots from a wal file 9736 ** METHOD: sqlite3_snapshot 9737 ** 9738 ** If a [WAL file] remains on disk after all database connections close 9739 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9740 ** or because the last process to have the database opened exited without 9741 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9742 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9743 ** will only be able to open the last transaction added to the WAL file 9744 ** even though the WAL file contains other valid transactions. 9745 ** 9746 ** This function attempts to scan the WAL file associated with database zDb 9747 ** of database handle db and make all valid snapshots available to 9748 ** sqlite3_snapshot_open(). It is an error if there is already a read 9749 ** transaction open on the database, or if the database is not a WAL mode 9750 ** database. 9751 ** 9752 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9753 ** 9754 ** This interface is only available if SQLite is compiled with the 9755 ** [SQLITE_ENABLE_SNAPSHOT] option. 9756 */ 9757 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9758 9759 /* 9760 ** CAPI3REF: Serialize a database 9761 ** 9762 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9763 ** that is a serialization of the S database on [database connection] D. 9764 ** If P is not a NULL pointer, then the size of the database in bytes 9765 ** is written into *P. 9766 ** 9767 ** For an ordinary on-disk database file, the serialization is just a 9768 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9769 ** the serialization is the same sequence of bytes which would be written 9770 ** to disk if that database where backed up to disk. 9771 ** 9772 ** The usual case is that sqlite3_serialize() copies the serialization of 9773 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9774 ** a pointer to that memory. The caller is responsible for freeing the 9775 ** returned value to avoid a memory leak. However, if the F argument 9776 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9777 ** are made, and the sqlite3_serialize() function will return a pointer 9778 ** to the contiguous memory representation of the database that SQLite 9779 ** is currently using for that database, or NULL if the no such contiguous 9780 ** memory representation of the database exists. A contiguous memory 9781 ** representation of the database will usually only exist if there has 9782 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9783 ** values of D and S. 9784 ** The size of the database is written into *P even if the 9785 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9786 ** of the database exists. 9787 ** 9788 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9789 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9790 ** allocation error occurs. 9791 ** 9792 ** This interface is only available if SQLite is compiled with the 9793 ** [SQLITE_ENABLE_DESERIALIZE] option. 9794 */ 9795 SQLITE_API unsigned char *sqlite3_serialize( 9796 sqlite3 *db, /* The database connection */ 9797 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9798 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9799 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9800 ); 9801 9802 /* 9803 ** CAPI3REF: Flags for sqlite3_serialize 9804 ** 9805 ** Zero or more of the following constants can be OR-ed together for 9806 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9807 ** 9808 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9809 ** a pointer to contiguous in-memory database that it is currently using, 9810 ** without making a copy of the database. If SQLite is not currently using 9811 ** a contiguous in-memory database, then this option causes 9812 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9813 ** using a contiguous in-memory database if it has been initialized by a 9814 ** prior call to [sqlite3_deserialize()]. 9815 */ 9816 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9817 9818 /* 9819 ** CAPI3REF: Deserialize a database 9820 ** 9821 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9822 ** [database connection] D to disconnect from database S and then 9823 ** reopen S as an in-memory database based on the serialization contained 9824 ** in P. The serialized database P is N bytes in size. M is the size of 9825 ** the buffer P, which might be larger than N. If M is larger than N, and 9826 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9827 ** permitted to add content to the in-memory database as long as the total 9828 ** size does not exceed M bytes. 9829 ** 9830 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9831 ** invoke sqlite3_free() on the serialization buffer when the database 9832 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9833 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9834 ** if writes on the database cause it to grow larger than M bytes. 9835 ** 9836 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9837 ** database is currently in a read transaction or is involved in a backup 9838 ** operation. 9839 ** 9840 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9841 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9842 ** [sqlite3_free()] is invoked on argument P prior to returning. 9843 ** 9844 ** This interface is only available if SQLite is compiled with the 9845 ** [SQLITE_ENABLE_DESERIALIZE] option. 9846 */ 9847 SQLITE_API int sqlite3_deserialize( 9848 sqlite3 *db, /* The database connection */ 9849 const char *zSchema, /* Which DB to reopen with the deserialization */ 9850 unsigned char *pData, /* The serialized database content */ 9851 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9852 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9853 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9854 ); 9855 9856 /* 9857 ** CAPI3REF: Flags for sqlite3_deserialize() 9858 ** 9859 ** The following are allowed values for 6th argument (the F argument) to 9860 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9861 ** 9862 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9863 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9864 ** and that SQLite should take ownership of this memory and automatically 9865 ** free it when it has finished using it. Without this flag, the caller 9866 ** is responsible for freeing any dynamically allocated memory. 9867 ** 9868 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9869 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9870 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9871 ** Without this flag, the deserialized database cannot increase in size beyond 9872 ** the number of bytes specified by the M parameter. 9873 ** 9874 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9875 ** should be treated as read-only. 9876 */ 9877 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9878 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9879 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9880 9881 /* 9882 ** Undo the hack that converts floating point types to integer for 9883 ** builds on processors without floating point support. 9884 */ 9885 #ifdef SQLITE_OMIT_FLOATING_POINT 9886 # undef double 9887 #endif 9888 9889 #ifdef __cplusplus 9890 } /* End of the 'extern "C"' block */ 9891 #endif 9892 #endif /* SQLITE3_H */ 9893 9894 /******** Begin file sqlite3rtree.h *********/ 9895 /* 9896 ** 2010 August 30 9897 ** 9898 ** The author disclaims copyright to this source code. In place of 9899 ** a legal notice, here is a blessing: 9900 ** 9901 ** May you do good and not evil. 9902 ** May you find forgiveness for yourself and forgive others. 9903 ** May you share freely, never taking more than you give. 9904 ** 9905 ************************************************************************* 9906 */ 9907 9908 #ifndef _SQLITE3RTREE_H_ 9909 #define _SQLITE3RTREE_H_ 9910 9911 9912 #ifdef __cplusplus 9913 extern "C" { 9914 #endif 9915 9916 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9917 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9918 9919 /* The double-precision datatype used by RTree depends on the 9920 ** SQLITE_RTREE_INT_ONLY compile-time option. 9921 */ 9922 #ifdef SQLITE_RTREE_INT_ONLY 9923 typedef sqlite3_int64 sqlite3_rtree_dbl; 9924 #else 9925 typedef double sqlite3_rtree_dbl; 9926 #endif 9927 9928 /* 9929 ** Register a geometry callback named zGeom that can be used as part of an 9930 ** R-Tree geometry query as follows: 9931 ** 9932 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9933 */ 9934 SQLITE_API int sqlite3_rtree_geometry_callback( 9935 sqlite3 *db, 9936 const char *zGeom, 9937 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9938 void *pContext 9939 ); 9940 9941 9942 /* 9943 ** A pointer to a structure of the following type is passed as the first 9944 ** argument to callbacks registered using rtree_geometry_callback(). 9945 */ 9946 struct sqlite3_rtree_geometry { 9947 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9948 int nParam; /* Size of array aParam[] */ 9949 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9950 void *pUser; /* Callback implementation user data */ 9951 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9952 }; 9953 9954 /* 9955 ** Register a 2nd-generation geometry callback named zScore that can be 9956 ** used as part of an R-Tree geometry query as follows: 9957 ** 9958 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9959 */ 9960 SQLITE_API int sqlite3_rtree_query_callback( 9961 sqlite3 *db, 9962 const char *zQueryFunc, 9963 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9964 void *pContext, 9965 void (*xDestructor)(void*) 9966 ); 9967 9968 9969 /* 9970 ** A pointer to a structure of the following type is passed as the 9971 ** argument to scored geometry callback registered using 9972 ** sqlite3_rtree_query_callback(). 9973 ** 9974 ** Note that the first 5 fields of this structure are identical to 9975 ** sqlite3_rtree_geometry. This structure is a subclass of 9976 ** sqlite3_rtree_geometry. 9977 */ 9978 struct sqlite3_rtree_query_info { 9979 void *pContext; /* pContext from when function registered */ 9980 int nParam; /* Number of function parameters */ 9981 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9982 void *pUser; /* callback can use this, if desired */ 9983 void (*xDelUser)(void*); /* function to free pUser */ 9984 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9985 unsigned int *anQueue; /* Number of pending entries in the queue */ 9986 int nCoord; /* Number of coordinates */ 9987 int iLevel; /* Level of current node or entry */ 9988 int mxLevel; /* The largest iLevel value in the tree */ 9989 sqlite3_int64 iRowid; /* Rowid for current entry */ 9990 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9991 int eParentWithin; /* Visibility of parent node */ 9992 int eWithin; /* OUT: Visibility */ 9993 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9994 /* The following fields are only available in 3.8.11 and later */ 9995 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9996 }; 9997 9998 /* 9999 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10000 */ 10001 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10002 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10003 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10004 10005 10006 #ifdef __cplusplus 10007 } /* end of the 'extern "C"' block */ 10008 #endif 10009 10010 #endif /* ifndef _SQLITE3RTREE_H_ */ 10011 10012 /******** End of sqlite3rtree.h *********/ 10013 /******** Begin file sqlite3session.h *********/ 10014 10015 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10016 #define __SQLITESESSION_H_ 1 10017 10018 /* 10019 ** Make sure we can call this stuff from C++. 10020 */ 10021 #ifdef __cplusplus 10022 extern "C" { 10023 #endif 10024 10025 10026 /* 10027 ** CAPI3REF: Session Object Handle 10028 ** 10029 ** An instance of this object is a [session] that can be used to 10030 ** record changes to a database. 10031 */ 10032 typedef struct sqlite3_session sqlite3_session; 10033 10034 /* 10035 ** CAPI3REF: Changeset Iterator Handle 10036 ** 10037 ** An instance of this object acts as a cursor for iterating 10038 ** over the elements of a [changeset] or [patchset]. 10039 */ 10040 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10041 10042 /* 10043 ** CAPI3REF: Create A New Session Object 10044 ** CONSTRUCTOR: sqlite3_session 10045 ** 10046 ** Create a new session object attached to database handle db. If successful, 10047 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10048 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10049 ** error code (e.g. SQLITE_NOMEM) is returned. 10050 ** 10051 ** It is possible to create multiple session objects attached to a single 10052 ** database handle. 10053 ** 10054 ** Session objects created using this function should be deleted using the 10055 ** [sqlite3session_delete()] function before the database handle that they 10056 ** are attached to is itself closed. If the database handle is closed before 10057 ** the session object is deleted, then the results of calling any session 10058 ** module function, including [sqlite3session_delete()] on the session object 10059 ** are undefined. 10060 ** 10061 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10062 ** is not possible for an application to register a pre-update hook on a 10063 ** database handle that has one or more session objects attached. Nor is 10064 ** it possible to create a session object attached to a database handle for 10065 ** which a pre-update hook is already defined. The results of attempting 10066 ** either of these things are undefined. 10067 ** 10068 ** The session object will be used to create changesets for tables in 10069 ** database zDb, where zDb is either "main", or "temp", or the name of an 10070 ** attached database. It is not an error if database zDb is not attached 10071 ** to the database when the session object is created. 10072 */ 10073 SQLITE_API int sqlite3session_create( 10074 sqlite3 *db, /* Database handle */ 10075 const char *zDb, /* Name of db (e.g. "main") */ 10076 sqlite3_session **ppSession /* OUT: New session object */ 10077 ); 10078 10079 /* 10080 ** CAPI3REF: Delete A Session Object 10081 ** DESTRUCTOR: sqlite3_session 10082 ** 10083 ** Delete a session object previously allocated using 10084 ** [sqlite3session_create()]. Once a session object has been deleted, the 10085 ** results of attempting to use pSession with any other session module 10086 ** function are undefined. 10087 ** 10088 ** Session objects must be deleted before the database handle to which they 10089 ** are attached is closed. Refer to the documentation for 10090 ** [sqlite3session_create()] for details. 10091 */ 10092 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10093 10094 10095 /* 10096 ** CAPI3REF: Enable Or Disable A Session Object 10097 ** METHOD: sqlite3_session 10098 ** 10099 ** Enable or disable the recording of changes by a session object. When 10100 ** enabled, a session object records changes made to the database. When 10101 ** disabled - it does not. A newly created session object is enabled. 10102 ** Refer to the documentation for [sqlite3session_changeset()] for further 10103 ** details regarding how enabling and disabling a session object affects 10104 ** the eventual changesets. 10105 ** 10106 ** Passing zero to this function disables the session. Passing a value 10107 ** greater than zero enables it. Passing a value less than zero is a 10108 ** no-op, and may be used to query the current state of the session. 10109 ** 10110 ** The return value indicates the final state of the session object: 0 if 10111 ** the session is disabled, or 1 if it is enabled. 10112 */ 10113 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10114 10115 /* 10116 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10117 ** METHOD: sqlite3_session 10118 ** 10119 ** Each change recorded by a session object is marked as either direct or 10120 ** indirect. A change is marked as indirect if either: 10121 ** 10122 ** <ul> 10123 ** <li> The session object "indirect" flag is set when the change is 10124 ** made, or 10125 ** <li> The change is made by an SQL trigger or foreign key action 10126 ** instead of directly as a result of a users SQL statement. 10127 ** </ul> 10128 ** 10129 ** If a single row is affected by more than one operation within a session, 10130 ** then the change is considered indirect if all operations meet the criteria 10131 ** for an indirect change above, or direct otherwise. 10132 ** 10133 ** This function is used to set, clear or query the session object indirect 10134 ** flag. If the second argument passed to this function is zero, then the 10135 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10136 ** is set. Passing a value less than zero does not modify the current value 10137 ** of the indirect flag, and may be used to query the current state of the 10138 ** indirect flag for the specified session object. 10139 ** 10140 ** The return value indicates the final state of the indirect flag: 0 if 10141 ** it is clear, or 1 if it is set. 10142 */ 10143 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10144 10145 /* 10146 ** CAPI3REF: Attach A Table To A Session Object 10147 ** METHOD: sqlite3_session 10148 ** 10149 ** If argument zTab is not NULL, then it is the name of a table to attach 10150 ** to the session object passed as the first argument. All subsequent changes 10151 ** made to the table while the session object is enabled will be recorded. See 10152 ** documentation for [sqlite3session_changeset()] for further details. 10153 ** 10154 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10155 ** in the database. If additional tables are added to the database (by 10156 ** executing "CREATE TABLE" statements) after this call is made, changes for 10157 ** the new tables are also recorded. 10158 ** 10159 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10160 ** defined as part of their CREATE TABLE statement. It does not matter if the 10161 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10162 ** KEY may consist of a single column, or may be a composite key. 10163 ** 10164 ** It is not an error if the named table does not exist in the database. Nor 10165 ** is it an error if the named table does not have a PRIMARY KEY. However, 10166 ** no changes will be recorded in either of these scenarios. 10167 ** 10168 ** Changes are not recorded for individual rows that have NULL values stored 10169 ** in one or more of their PRIMARY KEY columns. 10170 ** 10171 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10172 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10173 ** 10174 ** <h3>Special sqlite_stat1 Handling</h3> 10175 ** 10176 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10177 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10178 ** <pre> 10179 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10180 ** </pre> 10181 ** 10182 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10183 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10184 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10185 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10186 ** patchset instead of a NULL value. This allows such changesets to be 10187 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10188 ** concat() and similar. 10189 ** 10190 ** The sqlite3changeset_apply() function automatically converts the 10191 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10192 ** table. However, if the application calls sqlite3changeset_new(), 10193 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10194 ** iterator directly (including on a changeset iterator passed to a 10195 ** conflict-handler callback) then the X'' value is returned. The application 10196 ** must translate X'' to NULL itself if required. 10197 ** 10198 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10199 ** changes made to the sqlite_stat1 table. Legacy versions of the 10200 ** sqlite3changeset_apply() function silently ignore any modifications to the 10201 ** sqlite_stat1 table that are part of a changeset or patchset. 10202 */ 10203 SQLITE_API int sqlite3session_attach( 10204 sqlite3_session *pSession, /* Session object */ 10205 const char *zTab /* Table name */ 10206 ); 10207 10208 /* 10209 ** CAPI3REF: Set a table filter on a Session Object. 10210 ** METHOD: sqlite3_session 10211 ** 10212 ** The second argument (xFilter) is the "filter callback". For changes to rows 10213 ** in tables that are not attached to the Session object, the filter is called 10214 ** to determine whether changes to the table's rows should be tracked or not. 10215 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10216 ** attached, xFilter will not be called again. 10217 */ 10218 SQLITE_API void sqlite3session_table_filter( 10219 sqlite3_session *pSession, /* Session object */ 10220 int(*xFilter)( 10221 void *pCtx, /* Copy of third arg to _filter_table() */ 10222 const char *zTab /* Table name */ 10223 ), 10224 void *pCtx /* First argument passed to xFilter */ 10225 ); 10226 10227 /* 10228 ** CAPI3REF: Generate A Changeset From A Session Object 10229 ** METHOD: sqlite3_session 10230 ** 10231 ** Obtain a changeset containing changes to the tables attached to the 10232 ** session object passed as the first argument. If successful, 10233 ** set *ppChangeset to point to a buffer containing the changeset 10234 ** and *pnChangeset to the size of the changeset in bytes before returning 10235 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10236 ** zero and return an SQLite error code. 10237 ** 10238 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10239 ** each representing a change to a single row of an attached table. An INSERT 10240 ** change contains the values of each field of a new database row. A DELETE 10241 ** contains the original values of each field of a deleted database row. An 10242 ** UPDATE change contains the original values of each field of an updated 10243 ** database row along with the updated values for each updated non-primary-key 10244 ** column. It is not possible for an UPDATE change to represent a change that 10245 ** modifies the values of primary key columns. If such a change is made, it 10246 ** is represented in a changeset as a DELETE followed by an INSERT. 10247 ** 10248 ** Changes are not recorded for rows that have NULL values stored in one or 10249 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10250 ** no corresponding change is present in the changesets returned by this 10251 ** function. If an existing row with one or more NULL values stored in 10252 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10253 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10254 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10255 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10256 ** DELETE change only. 10257 ** 10258 ** The contents of a changeset may be traversed using an iterator created 10259 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10260 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10261 ** API. 10262 ** 10263 ** Within a changeset generated by this function, all changes related to a 10264 ** single table are grouped together. In other words, when iterating through 10265 ** a changeset or when applying a changeset to a database, all changes related 10266 ** to a single table are processed before moving on to the next table. Tables 10267 ** are sorted in the same order in which they were attached (or auto-attached) 10268 ** to the sqlite3_session object. The order in which the changes related to 10269 ** a single table are stored is undefined. 10270 ** 10271 ** Following a successful call to this function, it is the responsibility of 10272 ** the caller to eventually free the buffer that *ppChangeset points to using 10273 ** [sqlite3_free()]. 10274 ** 10275 ** <h3>Changeset Generation</h3> 10276 ** 10277 ** Once a table has been attached to a session object, the session object 10278 ** records the primary key values of all new rows inserted into the table. 10279 ** It also records the original primary key and other column values of any 10280 ** deleted or updated rows. For each unique primary key value, data is only 10281 ** recorded once - the first time a row with said primary key is inserted, 10282 ** updated or deleted in the lifetime of the session. 10283 ** 10284 ** There is one exception to the previous paragraph: when a row is inserted, 10285 ** updated or deleted, if one or more of its primary key columns contain a 10286 ** NULL value, no record of the change is made. 10287 ** 10288 ** The session object therefore accumulates two types of records - those 10289 ** that consist of primary key values only (created when the user inserts 10290 ** a new record) and those that consist of the primary key values and the 10291 ** original values of other table columns (created when the users deletes 10292 ** or updates a record). 10293 ** 10294 ** When this function is called, the requested changeset is created using 10295 ** both the accumulated records and the current contents of the database 10296 ** file. Specifically: 10297 ** 10298 ** <ul> 10299 ** <li> For each record generated by an insert, the database is queried 10300 ** for a row with a matching primary key. If one is found, an INSERT 10301 ** change is added to the changeset. If no such row is found, no change 10302 ** is added to the changeset. 10303 ** 10304 ** <li> For each record generated by an update or delete, the database is 10305 ** queried for a row with a matching primary key. If such a row is 10306 ** found and one or more of the non-primary key fields have been 10307 ** modified from their original values, an UPDATE change is added to 10308 ** the changeset. Or, if no such row is found in the table, a DELETE 10309 ** change is added to the changeset. If there is a row with a matching 10310 ** primary key in the database, but all fields contain their original 10311 ** values, no change is added to the changeset. 10312 ** </ul> 10313 ** 10314 ** This means, amongst other things, that if a row is inserted and then later 10315 ** deleted while a session object is active, neither the insert nor the delete 10316 ** will be present in the changeset. Or if a row is deleted and then later a 10317 ** row with the same primary key values inserted while a session object is 10318 ** active, the resulting changeset will contain an UPDATE change instead of 10319 ** a DELETE and an INSERT. 10320 ** 10321 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10322 ** it does not accumulate records when rows are inserted, updated or deleted. 10323 ** This may appear to have some counter-intuitive effects if a single row 10324 ** is written to more than once during a session. For example, if a row 10325 ** is inserted while a session object is enabled, then later deleted while 10326 ** the same session object is disabled, no INSERT record will appear in the 10327 ** changeset, even though the delete took place while the session was disabled. 10328 ** Or, if one field of a row is updated while a session is disabled, and 10329 ** another field of the same row is updated while the session is enabled, the 10330 ** resulting changeset will contain an UPDATE change that updates both fields. 10331 */ 10332 SQLITE_API int sqlite3session_changeset( 10333 sqlite3_session *pSession, /* Session object */ 10334 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10335 void **ppChangeset /* OUT: Buffer containing changeset */ 10336 ); 10337 10338 /* 10339 ** CAPI3REF: Load The Difference Between Tables Into A Session 10340 ** METHOD: sqlite3_session 10341 ** 10342 ** If it is not already attached to the session object passed as the first 10343 ** argument, this function attaches table zTbl in the same manner as the 10344 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10345 ** does not have a primary key, this function is a no-op (but does not return 10346 ** an error). 10347 ** 10348 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10349 ** attached to the same database handle as the session object that contains 10350 ** a table compatible with the table attached to the session by this function. 10351 ** A table is considered compatible if it: 10352 ** 10353 ** <ul> 10354 ** <li> Has the same name, 10355 ** <li> Has the same set of columns declared in the same order, and 10356 ** <li> Has the same PRIMARY KEY definition. 10357 ** </ul> 10358 ** 10359 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10360 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10361 ** but no changes are added to the session object. As with other session 10362 ** APIs, tables without PRIMARY KEYs are simply ignored. 10363 ** 10364 ** This function adds a set of changes to the session object that could be 10365 ** used to update the table in database zFrom (call this the "from-table") 10366 ** so that its content is the same as the table attached to the session 10367 ** object (call this the "to-table"). Specifically: 10368 ** 10369 ** <ul> 10370 ** <li> For each row (primary key) that exists in the to-table but not in 10371 ** the from-table, an INSERT record is added to the session object. 10372 ** 10373 ** <li> For each row (primary key) that exists in the to-table but not in 10374 ** the from-table, a DELETE record is added to the session object. 10375 ** 10376 ** <li> For each row (primary key) that exists in both tables, but features 10377 ** different non-PK values in each, an UPDATE record is added to the 10378 ** session. 10379 ** </ul> 10380 ** 10381 ** To clarify, if this function is called and then a changeset constructed 10382 ** using [sqlite3session_changeset()], then after applying that changeset to 10383 ** database zFrom the contents of the two compatible tables would be 10384 ** identical. 10385 ** 10386 ** It an error if database zFrom does not exist or does not contain the 10387 ** required compatible table. 10388 ** 10389 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10390 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10391 ** may be set to point to a buffer containing an English language error 10392 ** message. It is the responsibility of the caller to free this buffer using 10393 ** sqlite3_free(). 10394 */ 10395 SQLITE_API int sqlite3session_diff( 10396 sqlite3_session *pSession, 10397 const char *zFromDb, 10398 const char *zTbl, 10399 char **pzErrMsg 10400 ); 10401 10402 10403 /* 10404 ** CAPI3REF: Generate A Patchset From A Session Object 10405 ** METHOD: sqlite3_session 10406 ** 10407 ** The differences between a patchset and a changeset are that: 10408 ** 10409 ** <ul> 10410 ** <li> DELETE records consist of the primary key fields only. The 10411 ** original values of other fields are omitted. 10412 ** <li> The original values of any modified fields are omitted from 10413 ** UPDATE records. 10414 ** </ul> 10415 ** 10416 ** A patchset blob may be used with up to date versions of all 10417 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10418 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10419 ** attempting to use a patchset blob with old versions of the 10420 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10421 ** 10422 ** Because the non-primary key "old.*" fields are omitted, no 10423 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10424 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10425 ** in the same way as for changesets. 10426 ** 10427 ** Changes within a patchset are ordered in the same way as for changesets 10428 ** generated by the sqlite3session_changeset() function (i.e. all changes for 10429 ** a single table are grouped together, tables appear in the order in which 10430 ** they were attached to the session object). 10431 */ 10432 SQLITE_API int sqlite3session_patchset( 10433 sqlite3_session *pSession, /* Session object */ 10434 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10435 void **ppPatchset /* OUT: Buffer containing patchset */ 10436 ); 10437 10438 /* 10439 ** CAPI3REF: Test if a changeset has recorded any changes. 10440 ** 10441 ** Return non-zero if no changes to attached tables have been recorded by 10442 ** the session object passed as the first argument. Otherwise, if one or 10443 ** more changes have been recorded, return zero. 10444 ** 10445 ** Even if this function returns zero, it is possible that calling 10446 ** [sqlite3session_changeset()] on the session handle may still return a 10447 ** changeset that contains no changes. This can happen when a row in 10448 ** an attached table is modified and then later on the original values 10449 ** are restored. However, if this function returns non-zero, then it is 10450 ** guaranteed that a call to sqlite3session_changeset() will return a 10451 ** changeset containing zero changes. 10452 */ 10453 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10454 10455 /* 10456 ** CAPI3REF: Query for the amount of heap memory used by a session object. 10457 ** 10458 ** This API returns the total amount of heap memory in bytes currently 10459 ** used by the session object passed as the only argument. 10460 */ 10461 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 10462 10463 /* 10464 ** CAPI3REF: Create An Iterator To Traverse A Changeset 10465 ** CONSTRUCTOR: sqlite3_changeset_iter 10466 ** 10467 ** Create an iterator used to iterate through the contents of a changeset. 10468 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10469 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10470 ** SQLite error code is returned. 10471 ** 10472 ** The following functions can be used to advance and query a changeset 10473 ** iterator created by this function: 10474 ** 10475 ** <ul> 10476 ** <li> [sqlite3changeset_next()] 10477 ** <li> [sqlite3changeset_op()] 10478 ** <li> [sqlite3changeset_new()] 10479 ** <li> [sqlite3changeset_old()] 10480 ** </ul> 10481 ** 10482 ** It is the responsibility of the caller to eventually destroy the iterator 10483 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10484 ** changeset (pChangeset) must remain valid until after the iterator is 10485 ** destroyed. 10486 ** 10487 ** Assuming the changeset blob was created by one of the 10488 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10489 ** [sqlite3changeset_invert()] functions, all changes within the changeset 10490 ** that apply to a single table are grouped together. This means that when 10491 ** an application iterates through a changeset using an iterator created by 10492 ** this function, all changes that relate to a single table are visited 10493 ** consecutively. There is no chance that the iterator will visit a change 10494 ** the applies to table X, then one for table Y, and then later on visit 10495 ** another change for table X. 10496 ** 10497 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10498 ** may be modified by passing a combination of 10499 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10500 ** 10501 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10502 ** and therefore subject to change. 10503 */ 10504 SQLITE_API int sqlite3changeset_start( 10505 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10506 int nChangeset, /* Size of changeset blob in bytes */ 10507 void *pChangeset /* Pointer to blob containing changeset */ 10508 ); 10509 SQLITE_API int sqlite3changeset_start_v2( 10510 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10511 int nChangeset, /* Size of changeset blob in bytes */ 10512 void *pChangeset, /* Pointer to blob containing changeset */ 10513 int flags /* SESSION_CHANGESETSTART_* flags */ 10514 ); 10515 10516 /* 10517 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10518 ** 10519 ** The following flags may passed via the 4th parameter to 10520 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10521 ** 10522 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10523 ** Invert the changeset while iterating through it. This is equivalent to 10524 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10525 ** It is an error to specify this flag with a patchset. 10526 */ 10527 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10528 10529 10530 /* 10531 ** CAPI3REF: Advance A Changeset Iterator 10532 ** METHOD: sqlite3_changeset_iter 10533 ** 10534 ** This function may only be used with iterators created by the function 10535 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10536 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10537 ** is returned and the call has no effect. 10538 ** 10539 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10540 ** does not point to any change in the changeset. Assuming the changeset 10541 ** is not empty, the first call to this function advances the iterator to 10542 ** point to the first change in the changeset. Each subsequent call advances 10543 ** the iterator to point to the next change in the changeset (if any). If 10544 ** no error occurs and the iterator points to a valid change after a call 10545 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10546 ** Otherwise, if all changes in the changeset have already been visited, 10547 ** SQLITE_DONE is returned. 10548 ** 10549 ** If an error occurs, an SQLite error code is returned. Possible error 10550 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10551 ** SQLITE_NOMEM. 10552 */ 10553 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10554 10555 /* 10556 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10557 ** METHOD: sqlite3_changeset_iter 10558 ** 10559 ** The pIter argument passed to this function may either be an iterator 10560 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10561 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10562 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10563 ** is not the case, this function returns [SQLITE_MISUSE]. 10564 ** 10565 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 10566 ** outputs are set through these pointers: 10567 ** 10568 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 10569 ** depending on the type of change that the iterator currently points to; 10570 ** 10571 ** *pnCol is set to the number of columns in the table affected by the change; and 10572 ** 10573 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 10574 ** the name of the table affected by the current change. The buffer remains 10575 ** valid until either sqlite3changeset_next() is called on the iterator 10576 ** or until the conflict-handler function returns. 10577 ** 10578 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10579 ** is an indirect change, or false (0) otherwise. See the documentation for 10580 ** [sqlite3session_indirect()] for a description of direct and indirect 10581 ** changes. 10582 ** 10583 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10584 ** SQLite error code is returned. The values of the output variables may not 10585 ** be trusted in this case. 10586 */ 10587 SQLITE_API int sqlite3changeset_op( 10588 sqlite3_changeset_iter *pIter, /* Iterator object */ 10589 const char **pzTab, /* OUT: Pointer to table name */ 10590 int *pnCol, /* OUT: Number of columns in table */ 10591 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10592 int *pbIndirect /* OUT: True for an 'indirect' change */ 10593 ); 10594 10595 /* 10596 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10597 ** METHOD: sqlite3_changeset_iter 10598 ** 10599 ** For each modified table, a changeset includes the following: 10600 ** 10601 ** <ul> 10602 ** <li> The number of columns in the table, and 10603 ** <li> Which of those columns make up the tables PRIMARY KEY. 10604 ** </ul> 10605 ** 10606 ** This function is used to find which columns comprise the PRIMARY KEY of 10607 ** the table modified by the change that iterator pIter currently points to. 10608 ** If successful, *pabPK is set to point to an array of nCol entries, where 10609 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10610 ** 0x01 if the corresponding column is part of the tables primary key, or 10611 ** 0x00 if it is not. 10612 ** 10613 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10614 ** in the table. 10615 ** 10616 ** If this function is called when the iterator does not point to a valid 10617 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10618 ** SQLITE_OK is returned and the output variables populated as described 10619 ** above. 10620 */ 10621 SQLITE_API int sqlite3changeset_pk( 10622 sqlite3_changeset_iter *pIter, /* Iterator object */ 10623 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10624 int *pnCol /* OUT: Number of entries in output array */ 10625 ); 10626 10627 /* 10628 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10629 ** METHOD: sqlite3_changeset_iter 10630 ** 10631 ** The pIter argument passed to this function may either be an iterator 10632 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10633 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10634 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10635 ** Furthermore, it may only be called if the type of change that the iterator 10636 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10637 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10638 ** 10639 ** Argument iVal must be greater than or equal to 0, and less than the number 10640 ** of columns in the table affected by the current change. Otherwise, 10641 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10642 ** 10643 ** If successful, this function sets *ppValue to point to a protected 10644 ** sqlite3_value object containing the iVal'th value from the vector of 10645 ** original row values stored as part of the UPDATE or DELETE change and 10646 ** returns SQLITE_OK. The name of the function comes from the fact that this 10647 ** is similar to the "old.*" columns available to update or delete triggers. 10648 ** 10649 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10650 ** is returned and *ppValue is set to NULL. 10651 */ 10652 SQLITE_API int sqlite3changeset_old( 10653 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10654 int iVal, /* Column number */ 10655 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10656 ); 10657 10658 /* 10659 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10660 ** METHOD: sqlite3_changeset_iter 10661 ** 10662 ** The pIter argument passed to this function may either be an iterator 10663 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10664 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10665 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10666 ** Furthermore, it may only be called if the type of change that the iterator 10667 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10668 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10669 ** 10670 ** Argument iVal must be greater than or equal to 0, and less than the number 10671 ** of columns in the table affected by the current change. Otherwise, 10672 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10673 ** 10674 ** If successful, this function sets *ppValue to point to a protected 10675 ** sqlite3_value object containing the iVal'th value from the vector of 10676 ** new row values stored as part of the UPDATE or INSERT change and 10677 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10678 ** a new value for the requested column, *ppValue is set to NULL and 10679 ** SQLITE_OK returned. The name of the function comes from the fact that 10680 ** this is similar to the "new.*" columns available to update or delete 10681 ** triggers. 10682 ** 10683 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10684 ** is returned and *ppValue is set to NULL. 10685 */ 10686 SQLITE_API int sqlite3changeset_new( 10687 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10688 int iVal, /* Column number */ 10689 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10690 ); 10691 10692 /* 10693 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10694 ** METHOD: sqlite3_changeset_iter 10695 ** 10696 ** This function should only be used with iterator objects passed to a 10697 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10698 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10699 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10700 ** is set to NULL. 10701 ** 10702 ** Argument iVal must be greater than or equal to 0, and less than the number 10703 ** of columns in the table affected by the current change. Otherwise, 10704 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10705 ** 10706 ** If successful, this function sets *ppValue to point to a protected 10707 ** sqlite3_value object containing the iVal'th value from the 10708 ** "conflicting row" associated with the current conflict-handler callback 10709 ** and returns SQLITE_OK. 10710 ** 10711 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10712 ** is returned and *ppValue is set to NULL. 10713 */ 10714 SQLITE_API int sqlite3changeset_conflict( 10715 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10716 int iVal, /* Column number */ 10717 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10718 ); 10719 10720 /* 10721 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10722 ** METHOD: sqlite3_changeset_iter 10723 ** 10724 ** This function may only be called with an iterator passed to an 10725 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10726 ** it sets the output variable to the total number of known foreign key 10727 ** violations in the destination database and returns SQLITE_OK. 10728 ** 10729 ** In all other cases this function returns SQLITE_MISUSE. 10730 */ 10731 SQLITE_API int sqlite3changeset_fk_conflicts( 10732 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10733 int *pnOut /* OUT: Number of FK violations */ 10734 ); 10735 10736 10737 /* 10738 ** CAPI3REF: Finalize A Changeset Iterator 10739 ** METHOD: sqlite3_changeset_iter 10740 ** 10741 ** This function is used to finalize an iterator allocated with 10742 ** [sqlite3changeset_start()]. 10743 ** 10744 ** This function should only be called on iterators created using the 10745 ** [sqlite3changeset_start()] function. If an application calls this 10746 ** function with an iterator passed to a conflict-handler by 10747 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10748 ** call has no effect. 10749 ** 10750 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10751 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10752 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10753 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10754 ** returned. This is to allow the following pattern (pseudo-code): 10755 ** 10756 ** <pre> 10757 ** sqlite3changeset_start(); 10758 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10759 ** // Do something with change. 10760 ** } 10761 ** rc = sqlite3changeset_finalize(); 10762 ** if( rc!=SQLITE_OK ){ 10763 ** // An error has occurred 10764 ** } 10765 ** </pre> 10766 */ 10767 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10768 10769 /* 10770 ** CAPI3REF: Invert A Changeset 10771 ** 10772 ** This function is used to "invert" a changeset object. Applying an inverted 10773 ** changeset to a database reverses the effects of applying the uninverted 10774 ** changeset. Specifically: 10775 ** 10776 ** <ul> 10777 ** <li> Each DELETE change is changed to an INSERT, and 10778 ** <li> Each INSERT change is changed to a DELETE, and 10779 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10780 ** </ul> 10781 ** 10782 ** This function does not change the order in which changes appear within 10783 ** the changeset. It merely reverses the sense of each individual change. 10784 ** 10785 ** If successful, a pointer to a buffer containing the inverted changeset 10786 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10787 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10788 ** zeroed and an SQLite error code returned. 10789 ** 10790 ** It is the responsibility of the caller to eventually call sqlite3_free() 10791 ** on the *ppOut pointer to free the buffer allocation following a successful 10792 ** call to this function. 10793 ** 10794 ** WARNING/TODO: This function currently assumes that the input is a valid 10795 ** changeset. If it is not, the results are undefined. 10796 */ 10797 SQLITE_API int sqlite3changeset_invert( 10798 int nIn, const void *pIn, /* Input changeset */ 10799 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10800 ); 10801 10802 /* 10803 ** CAPI3REF: Concatenate Two Changeset Objects 10804 ** 10805 ** This function is used to concatenate two changesets, A and B, into a 10806 ** single changeset. The result is a changeset equivalent to applying 10807 ** changeset A followed by changeset B. 10808 ** 10809 ** This function combines the two input changesets using an 10810 ** sqlite3_changegroup object. Calling it produces similar results as the 10811 ** following code fragment: 10812 ** 10813 ** <pre> 10814 ** sqlite3_changegroup *pGrp; 10815 ** rc = sqlite3_changegroup_new(&pGrp); 10816 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10817 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10818 ** if( rc==SQLITE_OK ){ 10819 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10820 ** }else{ 10821 ** *ppOut = 0; 10822 ** *pnOut = 0; 10823 ** } 10824 ** </pre> 10825 ** 10826 ** Refer to the sqlite3_changegroup documentation below for details. 10827 */ 10828 SQLITE_API int sqlite3changeset_concat( 10829 int nA, /* Number of bytes in buffer pA */ 10830 void *pA, /* Pointer to buffer containing changeset A */ 10831 int nB, /* Number of bytes in buffer pB */ 10832 void *pB, /* Pointer to buffer containing changeset B */ 10833 int *pnOut, /* OUT: Number of bytes in output changeset */ 10834 void **ppOut /* OUT: Buffer containing output changeset */ 10835 ); 10836 10837 10838 /* 10839 ** CAPI3REF: Changegroup Handle 10840 ** 10841 ** A changegroup is an object used to combine two or more 10842 ** [changesets] or [patchsets] 10843 */ 10844 typedef struct sqlite3_changegroup sqlite3_changegroup; 10845 10846 /* 10847 ** CAPI3REF: Create A New Changegroup Object 10848 ** CONSTRUCTOR: sqlite3_changegroup 10849 ** 10850 ** An sqlite3_changegroup object is used to combine two or more changesets 10851 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10852 ** object may combine changesets or patchsets, but not both. The output is 10853 ** always in the same format as the input. 10854 ** 10855 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10856 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10857 ** should eventually free the returned object using a call to 10858 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10859 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10860 ** 10861 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10862 ** 10863 ** <ul> 10864 ** <li> It is created using a call to sqlite3changegroup_new(). 10865 ** 10866 ** <li> Zero or more changesets (or patchsets) are added to the object 10867 ** by calling sqlite3changegroup_add(). 10868 ** 10869 ** <li> The result of combining all input changesets together is obtained 10870 ** by the application via a call to sqlite3changegroup_output(). 10871 ** 10872 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10873 ** </ul> 10874 ** 10875 ** Any number of calls to add() and output() may be made between the calls to 10876 ** new() and delete(), and in any order. 10877 ** 10878 ** As well as the regular sqlite3changegroup_add() and 10879 ** sqlite3changegroup_output() functions, also available are the streaming 10880 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10881 */ 10882 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10883 10884 /* 10885 ** CAPI3REF: Add A Changeset To A Changegroup 10886 ** METHOD: sqlite3_changegroup 10887 ** 10888 ** Add all changes within the changeset (or patchset) in buffer pData (size 10889 ** nData bytes) to the changegroup. 10890 ** 10891 ** If the buffer contains a patchset, then all prior calls to this function 10892 ** on the same changegroup object must also have specified patchsets. Or, if 10893 ** the buffer contains a changeset, so must have the earlier calls to this 10894 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10895 ** to the changegroup. 10896 ** 10897 ** Rows within the changeset and changegroup are identified by the values in 10898 ** their PRIMARY KEY columns. A change in the changeset is considered to 10899 ** apply to the same row as a change already present in the changegroup if 10900 ** the two rows have the same primary key. 10901 ** 10902 ** Changes to rows that do not already appear in the changegroup are 10903 ** simply copied into it. Or, if both the new changeset and the changegroup 10904 ** contain changes that apply to a single row, the final contents of the 10905 ** changegroup depends on the type of each change, as follows: 10906 ** 10907 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10908 ** <tr><th style="white-space:pre">Existing Change </th> 10909 ** <th style="white-space:pre">New Change </th> 10910 ** <th>Output Change 10911 ** <tr><td>INSERT <td>INSERT <td> 10912 ** The new change is ignored. This case does not occur if the new 10913 ** changeset was recorded immediately after the changesets already 10914 ** added to the changegroup. 10915 ** <tr><td>INSERT <td>UPDATE <td> 10916 ** The INSERT change remains in the changegroup. The values in the 10917 ** INSERT change are modified as if the row was inserted by the 10918 ** existing change and then updated according to the new change. 10919 ** <tr><td>INSERT <td>DELETE <td> 10920 ** The existing INSERT is removed from the changegroup. The DELETE is 10921 ** not added. 10922 ** <tr><td>UPDATE <td>INSERT <td> 10923 ** The new change is ignored. This case does not occur if the new 10924 ** changeset was recorded immediately after the changesets already 10925 ** added to the changegroup. 10926 ** <tr><td>UPDATE <td>UPDATE <td> 10927 ** The existing UPDATE remains within the changegroup. It is amended 10928 ** so that the accompanying values are as if the row was updated once 10929 ** by the existing change and then again by the new change. 10930 ** <tr><td>UPDATE <td>DELETE <td> 10931 ** The existing UPDATE is replaced by the new DELETE within the 10932 ** changegroup. 10933 ** <tr><td>DELETE <td>INSERT <td> 10934 ** If one or more of the column values in the row inserted by the 10935 ** new change differ from those in the row deleted by the existing 10936 ** change, the existing DELETE is replaced by an UPDATE within the 10937 ** changegroup. Otherwise, if the inserted row is exactly the same 10938 ** as the deleted row, the existing DELETE is simply discarded. 10939 ** <tr><td>DELETE <td>UPDATE <td> 10940 ** The new change is ignored. This case does not occur if the new 10941 ** changeset was recorded immediately after the changesets already 10942 ** added to the changegroup. 10943 ** <tr><td>DELETE <td>DELETE <td> 10944 ** The new change is ignored. This case does not occur if the new 10945 ** changeset was recorded immediately after the changesets already 10946 ** added to the changegroup. 10947 ** </table> 10948 ** 10949 ** If the new changeset contains changes to a table that is already present 10950 ** in the changegroup, then the number of columns and the position of the 10951 ** primary key columns for the table must be consistent. If this is not the 10952 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10953 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10954 ** returned. Or, if an out-of-memory condition occurs during processing, this 10955 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 10956 ** of the final contents of the changegroup is undefined. 10957 ** 10958 ** If no error occurs, SQLITE_OK is returned. 10959 */ 10960 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10961 10962 /* 10963 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10964 ** METHOD: sqlite3_changegroup 10965 ** 10966 ** Obtain a buffer containing a changeset (or patchset) representing the 10967 ** current contents of the changegroup. If the inputs to the changegroup 10968 ** were themselves changesets, the output is a changeset. Or, if the 10969 ** inputs were patchsets, the output is also a patchset. 10970 ** 10971 ** As with the output of the sqlite3session_changeset() and 10972 ** sqlite3session_patchset() functions, all changes related to a single 10973 ** table are grouped together in the output of this function. Tables appear 10974 ** in the same order as for the very first changeset added to the changegroup. 10975 ** If the second or subsequent changesets added to the changegroup contain 10976 ** changes for tables that do not appear in the first changeset, they are 10977 ** appended onto the end of the output changeset, again in the order in 10978 ** which they are first encountered. 10979 ** 10980 ** If an error occurs, an SQLite error code is returned and the output 10981 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10982 ** is returned and the output variables are set to the size of and a 10983 ** pointer to the output buffer, respectively. In this case it is the 10984 ** responsibility of the caller to eventually free the buffer using a 10985 ** call to sqlite3_free(). 10986 */ 10987 SQLITE_API int sqlite3changegroup_output( 10988 sqlite3_changegroup*, 10989 int *pnData, /* OUT: Size of output buffer in bytes */ 10990 void **ppData /* OUT: Pointer to output buffer */ 10991 ); 10992 10993 /* 10994 ** CAPI3REF: Delete A Changegroup Object 10995 ** DESTRUCTOR: sqlite3_changegroup 10996 */ 10997 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10998 10999 /* 11000 ** CAPI3REF: Apply A Changeset To A Database 11001 ** 11002 ** Apply a changeset or patchset to a database. These functions attempt to 11003 ** update the "main" database attached to handle db with the changes found in 11004 ** the changeset passed via the second and third arguments. 11005 ** 11006 ** The fourth argument (xFilter) passed to these functions is the "filter 11007 ** callback". If it is not NULL, then for each table affected by at least one 11008 ** change in the changeset, the filter callback is invoked with 11009 ** the table name as the second argument, and a copy of the context pointer 11010 ** passed as the sixth argument as the first. If the "filter callback" 11011 ** returns zero, then no attempt is made to apply any changes to the table. 11012 ** Otherwise, if the return value is non-zero or the xFilter argument to 11013 ** is NULL, all changes related to the table are attempted. 11014 ** 11015 ** For each table that is not excluded by the filter callback, this function 11016 ** tests that the target database contains a compatible table. A table is 11017 ** considered compatible if all of the following are true: 11018 ** 11019 ** <ul> 11020 ** <li> The table has the same name as the name recorded in the 11021 ** changeset, and 11022 ** <li> The table has at least as many columns as recorded in the 11023 ** changeset, and 11024 ** <li> The table has primary key columns in the same position as 11025 ** recorded in the changeset. 11026 ** </ul> 11027 ** 11028 ** If there is no compatible table, it is not an error, but none of the 11029 ** changes associated with the table are applied. A warning message is issued 11030 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11031 ** one such warning is issued for each table in the changeset. 11032 ** 11033 ** For each change for which there is a compatible table, an attempt is made 11034 ** to modify the table contents according to the UPDATE, INSERT or DELETE 11035 ** change. If a change cannot be applied cleanly, the conflict handler 11036 ** function passed as the fifth argument to sqlite3changeset_apply() may be 11037 ** invoked. A description of exactly when the conflict handler is invoked for 11038 ** each type of change is below. 11039 ** 11040 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11041 ** of passing anything other than a valid function pointer as the xConflict 11042 ** argument are undefined. 11043 ** 11044 ** Each time the conflict handler function is invoked, it must return one 11045 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11046 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11047 ** if the second argument passed to the conflict handler is either 11048 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11049 ** returns an illegal value, any changes already made are rolled back and 11050 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11051 ** actions are taken by sqlite3changeset_apply() depending on the value 11052 ** returned by each invocation of the conflict-handler function. Refer to 11053 ** the documentation for the three 11054 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11055 ** 11056 ** <dl> 11057 ** <dt>DELETE Changes<dd> 11058 ** For each DELETE change, the function checks if the target database 11059 ** contains a row with the same primary key value (or values) as the 11060 ** original row values stored in the changeset. If it does, and the values 11061 ** stored in all non-primary key columns also match the values stored in 11062 ** the changeset the row is deleted from the target database. 11063 ** 11064 ** If a row with matching primary key values is found, but one or more of 11065 ** the non-primary key fields contains a value different from the original 11066 ** row value stored in the changeset, the conflict-handler function is 11067 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11068 ** database table has more columns than are recorded in the changeset, 11069 ** only the values of those non-primary key fields are compared against 11070 ** the current database contents - any trailing database table columns 11071 ** are ignored. 11072 ** 11073 ** If no row with matching primary key values is found in the database, 11074 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11075 ** passed as the second argument. 11076 ** 11077 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11078 ** (which can only happen if a foreign key constraint is violated), the 11079 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11080 ** passed as the second argument. This includes the case where the DELETE 11081 ** operation is attempted because an earlier call to the conflict handler 11082 ** function returned [SQLITE_CHANGESET_REPLACE]. 11083 ** 11084 ** <dt>INSERT Changes<dd> 11085 ** For each INSERT change, an attempt is made to insert the new row into 11086 ** the database. If the changeset row contains fewer fields than the 11087 ** database table, the trailing fields are populated with their default 11088 ** values. 11089 ** 11090 ** If the attempt to insert the row fails because the database already 11091 ** contains a row with the same primary key values, the conflict handler 11092 ** function is invoked with the second argument set to 11093 ** [SQLITE_CHANGESET_CONFLICT]. 11094 ** 11095 ** If the attempt to insert the row fails because of some other constraint 11096 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11097 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11098 ** This includes the case where the INSERT operation is re-attempted because 11099 ** an earlier call to the conflict handler function returned 11100 ** [SQLITE_CHANGESET_REPLACE]. 11101 ** 11102 ** <dt>UPDATE Changes<dd> 11103 ** For each UPDATE change, the function checks if the target database 11104 ** contains a row with the same primary key value (or values) as the 11105 ** original row values stored in the changeset. If it does, and the values 11106 ** stored in all modified non-primary key columns also match the values 11107 ** stored in the changeset the row is updated within the target database. 11108 ** 11109 ** If a row with matching primary key values is found, but one or more of 11110 ** the modified non-primary key fields contains a value different from an 11111 ** original row value stored in the changeset, the conflict-handler function 11112 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11113 ** UPDATE changes only contain values for non-primary key fields that are 11114 ** to be modified, only those fields need to match the original values to 11115 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11116 ** 11117 ** If no row with matching primary key values is found in the database, 11118 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11119 ** passed as the second argument. 11120 ** 11121 ** If the UPDATE operation is attempted, but SQLite returns 11122 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11123 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11124 ** This includes the case where the UPDATE operation is attempted after 11125 ** an earlier call to the conflict handler function returned 11126 ** [SQLITE_CHANGESET_REPLACE]. 11127 ** </dl> 11128 ** 11129 ** It is safe to execute SQL statements, including those that write to the 11130 ** table that the callback related to, from within the xConflict callback. 11131 ** This can be used to further customize the application's conflict 11132 ** resolution strategy. 11133 ** 11134 ** All changes made by these functions are enclosed in a savepoint transaction. 11135 ** If any other error (aside from a constraint failure when attempting to 11136 ** write to the target database) occurs, then the savepoint transaction is 11137 ** rolled back, restoring the target database to its original state, and an 11138 ** SQLite error code returned. 11139 ** 11140 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11141 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11142 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11143 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11144 ** is set to the size of the buffer in bytes. It is the responsibility of the 11145 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11146 ** is only allocated and populated if one or more conflicts were encountered 11147 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11148 ** APIs for further details. 11149 ** 11150 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11151 ** may be modified by passing a combination of 11152 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11153 ** 11154 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11155 ** and therefore subject to change. 11156 */ 11157 SQLITE_API int sqlite3changeset_apply( 11158 sqlite3 *db, /* Apply change to "main" db of this handle */ 11159 int nChangeset, /* Size of changeset in bytes */ 11160 void *pChangeset, /* Changeset blob */ 11161 int(*xFilter)( 11162 void *pCtx, /* Copy of sixth arg to _apply() */ 11163 const char *zTab /* Table name */ 11164 ), 11165 int(*xConflict)( 11166 void *pCtx, /* Copy of sixth arg to _apply() */ 11167 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11168 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11169 ), 11170 void *pCtx /* First argument passed to xConflict */ 11171 ); 11172 SQLITE_API int sqlite3changeset_apply_v2( 11173 sqlite3 *db, /* Apply change to "main" db of this handle */ 11174 int nChangeset, /* Size of changeset in bytes */ 11175 void *pChangeset, /* Changeset blob */ 11176 int(*xFilter)( 11177 void *pCtx, /* Copy of sixth arg to _apply() */ 11178 const char *zTab /* Table name */ 11179 ), 11180 int(*xConflict)( 11181 void *pCtx, /* Copy of sixth arg to _apply() */ 11182 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11183 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11184 ), 11185 void *pCtx, /* First argument passed to xConflict */ 11186 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11187 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11188 ); 11189 11190 /* 11191 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11192 ** 11193 ** The following flags may passed via the 9th parameter to 11194 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11195 ** 11196 ** <dl> 11197 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11198 ** Usually, the sessions module encloses all operations performed by 11199 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11200 ** SAVEPOINT is committed if the changeset or patchset is successfully 11201 ** applied, or rolled back if an error occurs. Specifying this flag 11202 ** causes the sessions module to omit this savepoint. In this case, if the 11203 ** caller has an open transaction or savepoint when apply_v2() is called, 11204 ** it may revert the partially applied changeset by rolling it back. 11205 ** 11206 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11207 ** Invert the changeset before applying it. This is equivalent to inverting 11208 ** a changeset using sqlite3changeset_invert() before applying it. It is 11209 ** an error to specify this flag with a patchset. 11210 */ 11211 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11212 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11213 11214 /* 11215 ** CAPI3REF: Constants Passed To The Conflict Handler 11216 ** 11217 ** Values that may be passed as the second argument to a conflict-handler. 11218 ** 11219 ** <dl> 11220 ** <dt>SQLITE_CHANGESET_DATA<dd> 11221 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11222 ** when processing a DELETE or UPDATE change if a row with the required 11223 ** PRIMARY KEY fields is present in the database, but one or more other 11224 ** (non primary-key) fields modified by the update do not contain the 11225 ** expected "before" values. 11226 ** 11227 ** The conflicting row, in this case, is the database row with the matching 11228 ** primary key. 11229 ** 11230 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11231 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11232 ** argument when processing a DELETE or UPDATE change if a row with the 11233 ** required PRIMARY KEY fields is not present in the database. 11234 ** 11235 ** There is no conflicting row in this case. The results of invoking the 11236 ** sqlite3changeset_conflict() API are undefined. 11237 ** 11238 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11239 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11240 ** handler while processing an INSERT change if the operation would result 11241 ** in duplicate primary key values. 11242 ** 11243 ** The conflicting row in this case is the database row with the matching 11244 ** primary key. 11245 ** 11246 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11247 ** If foreign key handling is enabled, and applying a changeset leaves the 11248 ** database in a state containing foreign key violations, the conflict 11249 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11250 ** exactly once before the changeset is committed. If the conflict handler 11251 ** returns CHANGESET_OMIT, the changes, including those that caused the 11252 ** foreign key constraint violation, are committed. Or, if it returns 11253 ** CHANGESET_ABORT, the changeset is rolled back. 11254 ** 11255 ** No current or conflicting row information is provided. The only function 11256 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11257 ** is sqlite3changeset_fk_conflicts(). 11258 ** 11259 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11260 ** If any other constraint violation occurs while applying a change (i.e. 11261 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11262 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11263 ** 11264 ** There is no conflicting row in this case. The results of invoking the 11265 ** sqlite3changeset_conflict() API are undefined. 11266 ** 11267 ** </dl> 11268 */ 11269 #define SQLITE_CHANGESET_DATA 1 11270 #define SQLITE_CHANGESET_NOTFOUND 2 11271 #define SQLITE_CHANGESET_CONFLICT 3 11272 #define SQLITE_CHANGESET_CONSTRAINT 4 11273 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11274 11275 /* 11276 ** CAPI3REF: Constants Returned By The Conflict Handler 11277 ** 11278 ** A conflict handler callback must return one of the following three values. 11279 ** 11280 ** <dl> 11281 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11282 ** If a conflict handler returns this value no special action is taken. The 11283 ** change that caused the conflict is not applied. The session module 11284 ** continues to the next change in the changeset. 11285 ** 11286 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11287 ** This value may only be returned if the second argument to the conflict 11288 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11289 ** is not the case, any changes applied so far are rolled back and the 11290 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11291 ** 11292 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11293 ** handler, then the conflicting row is either updated or deleted, depending 11294 ** on the type of change. 11295 ** 11296 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11297 ** handler, then the conflicting row is removed from the database and a 11298 ** second attempt to apply the change is made. If this second attempt fails, 11299 ** the original row is restored to the database before continuing. 11300 ** 11301 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11302 ** If this value is returned, any changes applied so far are rolled back 11303 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11304 ** </dl> 11305 */ 11306 #define SQLITE_CHANGESET_OMIT 0 11307 #define SQLITE_CHANGESET_REPLACE 1 11308 #define SQLITE_CHANGESET_ABORT 2 11309 11310 /* 11311 ** CAPI3REF: Rebasing changesets 11312 ** EXPERIMENTAL 11313 ** 11314 ** Suppose there is a site hosting a database in state S0. And that 11315 ** modifications are made that move that database to state S1 and a 11316 ** changeset recorded (the "local" changeset). Then, a changeset based 11317 ** on S0 is received from another site (the "remote" changeset) and 11318 ** applied to the database. The database is then in state 11319 ** (S1+"remote"), where the exact state depends on any conflict 11320 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11321 ** Rebasing a changeset is to update it to take those conflict 11322 ** resolution decisions into account, so that the same conflicts 11323 ** do not have to be resolved elsewhere in the network. 11324 ** 11325 ** For example, if both the local and remote changesets contain an 11326 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11327 ** 11328 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11329 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11330 ** 11331 ** and the conflict resolution is REPLACE, then the INSERT change is 11332 ** removed from the local changeset (it was overridden). Or, if the 11333 ** conflict resolution was "OMIT", then the local changeset is modified 11334 ** to instead contain: 11335 ** 11336 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11337 ** 11338 ** Changes within the local changeset are rebased as follows: 11339 ** 11340 ** <dl> 11341 ** <dt>Local INSERT<dd> 11342 ** This may only conflict with a remote INSERT. If the conflict 11343 ** resolution was OMIT, then add an UPDATE change to the rebased 11344 ** changeset. Or, if the conflict resolution was REPLACE, add 11345 ** nothing to the rebased changeset. 11346 ** 11347 ** <dt>Local DELETE<dd> 11348 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11349 ** only possible resolution is OMIT. If the remote operation was a 11350 ** DELETE, then add no change to the rebased changeset. If the remote 11351 ** operation was an UPDATE, then the old.* fields of change are updated 11352 ** to reflect the new.* values in the UPDATE. 11353 ** 11354 ** <dt>Local UPDATE<dd> 11355 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11356 ** with a DELETE, and the conflict resolution was OMIT, then the update 11357 ** is changed into an INSERT. Any undefined values in the new.* record 11358 ** from the update change are filled in using the old.* values from 11359 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11360 ** the UPDATE change is simply omitted from the rebased changeset. 11361 ** 11362 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11363 ** the old.* values are rebased using the new.* values in the remote 11364 ** change. Or, if the resolution is REPLACE, then the change is copied 11365 ** into the rebased changeset with updates to columns also updated by 11366 ** the conflicting remote UPDATE removed. If this means no columns would 11367 ** be updated, the change is omitted. 11368 ** </dl> 11369 ** 11370 ** A local change may be rebased against multiple remote changes 11371 ** simultaneously. If a single key is modified by multiple remote 11372 ** changesets, they are combined as follows before the local changeset 11373 ** is rebased: 11374 ** 11375 ** <ul> 11376 ** <li> If there has been one or more REPLACE resolutions on a 11377 ** key, it is rebased according to a REPLACE. 11378 ** 11379 ** <li> If there have been no REPLACE resolutions on a key, then 11380 ** the local changeset is rebased according to the most recent 11381 ** of the OMIT resolutions. 11382 ** </ul> 11383 ** 11384 ** Note that conflict resolutions from multiple remote changesets are 11385 ** combined on a per-field basis, not per-row. This means that in the 11386 ** case of multiple remote UPDATE operations, some fields of a single 11387 ** local change may be rebased for REPLACE while others are rebased for 11388 ** OMIT. 11389 ** 11390 ** In order to rebase a local changeset, the remote changeset must first 11391 ** be applied to the local database using sqlite3changeset_apply_v2() and 11392 ** the buffer of rebase information captured. Then: 11393 ** 11394 ** <ol> 11395 ** <li> An sqlite3_rebaser object is created by calling 11396 ** sqlite3rebaser_create(). 11397 ** <li> The new object is configured with the rebase buffer obtained from 11398 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11399 ** If the local changeset is to be rebased against multiple remote 11400 ** changesets, then sqlite3rebaser_configure() should be called 11401 ** multiple times, in the same order that the multiple 11402 ** sqlite3changeset_apply_v2() calls were made. 11403 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11404 ** <li> The sqlite3_rebaser object is deleted by calling 11405 ** sqlite3rebaser_delete(). 11406 ** </ol> 11407 */ 11408 typedef struct sqlite3_rebaser sqlite3_rebaser; 11409 11410 /* 11411 ** CAPI3REF: Create a changeset rebaser object. 11412 ** EXPERIMENTAL 11413 ** 11414 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11415 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11416 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11417 ** to NULL. 11418 */ 11419 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11420 11421 /* 11422 ** CAPI3REF: Configure a changeset rebaser object. 11423 ** EXPERIMENTAL 11424 ** 11425 ** Configure the changeset rebaser object to rebase changesets according 11426 ** to the conflict resolutions described by buffer pRebase (size nRebase 11427 ** bytes), which must have been obtained from a previous call to 11428 ** sqlite3changeset_apply_v2(). 11429 */ 11430 SQLITE_API int sqlite3rebaser_configure( 11431 sqlite3_rebaser*, 11432 int nRebase, const void *pRebase 11433 ); 11434 11435 /* 11436 ** CAPI3REF: Rebase a changeset 11437 ** EXPERIMENTAL 11438 ** 11439 ** Argument pIn must point to a buffer containing a changeset nIn bytes 11440 ** in size. This function allocates and populates a buffer with a copy 11441 ** of the changeset rebased according to the configuration of the 11442 ** rebaser object passed as the first argument. If successful, (*ppOut) 11443 ** is set to point to the new buffer containing the rebased changeset and 11444 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11445 ** responsibility of the caller to eventually free the new buffer using 11446 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11447 ** are set to zero and an SQLite error code returned. 11448 */ 11449 SQLITE_API int sqlite3rebaser_rebase( 11450 sqlite3_rebaser*, 11451 int nIn, const void *pIn, 11452 int *pnOut, void **ppOut 11453 ); 11454 11455 /* 11456 ** CAPI3REF: Delete a changeset rebaser object. 11457 ** EXPERIMENTAL 11458 ** 11459 ** Delete the changeset rebaser object and all associated resources. There 11460 ** should be one call to this function for each successful invocation 11461 ** of sqlite3rebaser_create(). 11462 */ 11463 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11464 11465 /* 11466 ** CAPI3REF: Streaming Versions of API functions. 11467 ** 11468 ** The six streaming API xxx_strm() functions serve similar purposes to the 11469 ** corresponding non-streaming API functions: 11470 ** 11471 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11472 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11473 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11474 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11475 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11476 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11477 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11478 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11479 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11480 ** </table> 11481 ** 11482 ** Non-streaming functions that accept changesets (or patchsets) as input 11483 ** require that the entire changeset be stored in a single buffer in memory. 11484 ** Similarly, those that return a changeset or patchset do so by returning 11485 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 11486 ** Normally this is convenient. However, if an application running in a 11487 ** low-memory environment is required to handle very large changesets, the 11488 ** large contiguous memory allocations required can become onerous. 11489 ** 11490 ** In order to avoid this problem, instead of a single large buffer, input 11491 ** is passed to a streaming API functions by way of a callback function that 11492 ** the sessions module invokes to incrementally request input data as it is 11493 ** required. In all cases, a pair of API function parameters such as 11494 ** 11495 ** <pre> 11496 ** int nChangeset, 11497 ** void *pChangeset, 11498 ** </pre> 11499 ** 11500 ** Is replaced by: 11501 ** 11502 ** <pre> 11503 ** int (*xInput)(void *pIn, void *pData, int *pnData), 11504 ** void *pIn, 11505 ** </pre> 11506 ** 11507 ** Each time the xInput callback is invoked by the sessions module, the first 11508 ** argument passed is a copy of the supplied pIn context pointer. The second 11509 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11510 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11511 ** into the buffer and set (*pnData) to the actual number of bytes copied 11512 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11513 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11514 ** error code should be returned. In all cases, if an xInput callback returns 11515 ** an error, all processing is abandoned and the streaming API function 11516 ** returns a copy of the error code to the caller. 11517 ** 11518 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11519 ** invoked by the sessions module at any point during the lifetime of the 11520 ** iterator. If such an xInput callback returns an error, the iterator enters 11521 ** an error state, whereby all subsequent calls to iterator functions 11522 ** immediately fail with the same error code as returned by xInput. 11523 ** 11524 ** Similarly, streaming API functions that return changesets (or patchsets) 11525 ** return them in chunks by way of a callback function instead of via a 11526 ** pointer to a single large buffer. In this case, a pair of parameters such 11527 ** as: 11528 ** 11529 ** <pre> 11530 ** int *pnChangeset, 11531 ** void **ppChangeset, 11532 ** </pre> 11533 ** 11534 ** Is replaced by: 11535 ** 11536 ** <pre> 11537 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11538 ** void *pOut 11539 ** </pre> 11540 ** 11541 ** The xOutput callback is invoked zero or more times to return data to 11542 ** the application. The first parameter passed to each call is a copy of the 11543 ** pOut pointer supplied by the application. The second parameter, pData, 11544 ** points to a buffer nData bytes in size containing the chunk of output 11545 ** data being returned. If the xOutput callback successfully processes the 11546 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11547 ** it should return some other SQLite error code. In this case processing 11548 ** is immediately abandoned and the streaming API function returns a copy 11549 ** of the xOutput error code to the application. 11550 ** 11551 ** The sessions module never invokes an xOutput callback with the third 11552 ** parameter set to a value less than or equal to zero. Other than this, 11553 ** no guarantees are made as to the size of the chunks of data returned. 11554 */ 11555 SQLITE_API int sqlite3changeset_apply_strm( 11556 sqlite3 *db, /* Apply change to "main" db of this handle */ 11557 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11558 void *pIn, /* First arg for xInput */ 11559 int(*xFilter)( 11560 void *pCtx, /* Copy of sixth arg to _apply() */ 11561 const char *zTab /* Table name */ 11562 ), 11563 int(*xConflict)( 11564 void *pCtx, /* Copy of sixth arg to _apply() */ 11565 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11566 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11567 ), 11568 void *pCtx /* First argument passed to xConflict */ 11569 ); 11570 SQLITE_API int sqlite3changeset_apply_v2_strm( 11571 sqlite3 *db, /* Apply change to "main" db of this handle */ 11572 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11573 void *pIn, /* First arg for xInput */ 11574 int(*xFilter)( 11575 void *pCtx, /* Copy of sixth arg to _apply() */ 11576 const char *zTab /* Table name */ 11577 ), 11578 int(*xConflict)( 11579 void *pCtx, /* Copy of sixth arg to _apply() */ 11580 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11581 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11582 ), 11583 void *pCtx, /* First argument passed to xConflict */ 11584 void **ppRebase, int *pnRebase, 11585 int flags 11586 ); 11587 SQLITE_API int sqlite3changeset_concat_strm( 11588 int (*xInputA)(void *pIn, void *pData, int *pnData), 11589 void *pInA, 11590 int (*xInputB)(void *pIn, void *pData, int *pnData), 11591 void *pInB, 11592 int (*xOutput)(void *pOut, const void *pData, int nData), 11593 void *pOut 11594 ); 11595 SQLITE_API int sqlite3changeset_invert_strm( 11596 int (*xInput)(void *pIn, void *pData, int *pnData), 11597 void *pIn, 11598 int (*xOutput)(void *pOut, const void *pData, int nData), 11599 void *pOut 11600 ); 11601 SQLITE_API int sqlite3changeset_start_strm( 11602 sqlite3_changeset_iter **pp, 11603 int (*xInput)(void *pIn, void *pData, int *pnData), 11604 void *pIn 11605 ); 11606 SQLITE_API int sqlite3changeset_start_v2_strm( 11607 sqlite3_changeset_iter **pp, 11608 int (*xInput)(void *pIn, void *pData, int *pnData), 11609 void *pIn, 11610 int flags 11611 ); 11612 SQLITE_API int sqlite3session_changeset_strm( 11613 sqlite3_session *pSession, 11614 int (*xOutput)(void *pOut, const void *pData, int nData), 11615 void *pOut 11616 ); 11617 SQLITE_API int sqlite3session_patchset_strm( 11618 sqlite3_session *pSession, 11619 int (*xOutput)(void *pOut, const void *pData, int nData), 11620 void *pOut 11621 ); 11622 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11623 int (*xInput)(void *pIn, void *pData, int *pnData), 11624 void *pIn 11625 ); 11626 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11627 int (*xOutput)(void *pOut, const void *pData, int nData), 11628 void *pOut 11629 ); 11630 SQLITE_API int sqlite3rebaser_rebase_strm( 11631 sqlite3_rebaser *pRebaser, 11632 int (*xInput)(void *pIn, void *pData, int *pnData), 11633 void *pIn, 11634 int (*xOutput)(void *pOut, const void *pData, int nData), 11635 void *pOut 11636 ); 11637 11638 /* 11639 ** CAPI3REF: Configure global parameters 11640 ** 11641 ** The sqlite3session_config() interface is used to make global configuration 11642 ** changes to the sessions module in order to tune it to the specific needs 11643 ** of the application. 11644 ** 11645 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11646 ** while any other thread is inside any other sessions method then the 11647 ** results are undefined. Furthermore, if it is invoked after any sessions 11648 ** related objects have been created, the results are also undefined. 11649 ** 11650 ** The first argument to the sqlite3session_config() function must be one 11651 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11652 ** interpretation of the (void*) value passed as the second parameter and 11653 ** the effect of calling this function depends on the value of the first 11654 ** parameter. 11655 ** 11656 ** <dl> 11657 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11658 ** By default, the sessions module streaming interfaces attempt to input 11659 ** and output data in approximately 1 KiB chunks. This operand may be used 11660 ** to set and query the value of this configuration setting. The pointer 11661 ** passed as the second argument must point to a value of type (int). 11662 ** If this value is greater than 0, it is used as the new streaming data 11663 ** chunk size for both input and output. Before returning, the (int) value 11664 ** pointed to by pArg is set to the final value of the streaming interface 11665 ** chunk size. 11666 ** </dl> 11667 ** 11668 ** This function returns SQLITE_OK if successful, or an SQLite error code 11669 ** otherwise. 11670 */ 11671 SQLITE_API int sqlite3session_config(int op, void *pArg); 11672 11673 /* 11674 ** CAPI3REF: Values for sqlite3session_config(). 11675 */ 11676 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11677 11678 /* 11679 ** Make sure we can call this stuff from C++. 11680 */ 11681 #ifdef __cplusplus 11682 } 11683 #endif 11684 11685 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11686 11687 /******** End of sqlite3session.h *********/ 11688 /******** Begin file fts5.h *********/ 11689 /* 11690 ** 2014 May 31 11691 ** 11692 ** The author disclaims copyright to this source code. In place of 11693 ** a legal notice, here is a blessing: 11694 ** 11695 ** May you do good and not evil. 11696 ** May you find forgiveness for yourself and forgive others. 11697 ** May you share freely, never taking more than you give. 11698 ** 11699 ****************************************************************************** 11700 ** 11701 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11702 ** FTS5 may be extended with: 11703 ** 11704 ** * custom tokenizers, and 11705 ** * custom auxiliary functions. 11706 */ 11707 11708 11709 #ifndef _FTS5_H 11710 #define _FTS5_H 11711 11712 11713 #ifdef __cplusplus 11714 extern "C" { 11715 #endif 11716 11717 /************************************************************************* 11718 ** CUSTOM AUXILIARY FUNCTIONS 11719 ** 11720 ** Virtual table implementations may overload SQL functions by implementing 11721 ** the sqlite3_module.xFindFunction() method. 11722 */ 11723 11724 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11725 typedef struct Fts5Context Fts5Context; 11726 typedef struct Fts5PhraseIter Fts5PhraseIter; 11727 11728 typedef void (*fts5_extension_function)( 11729 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11730 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11731 sqlite3_context *pCtx, /* Context for returning result/error */ 11732 int nVal, /* Number of values in apVal[] array */ 11733 sqlite3_value **apVal /* Array of trailing arguments */ 11734 ); 11735 11736 struct Fts5PhraseIter { 11737 const unsigned char *a; 11738 const unsigned char *b; 11739 }; 11740 11741 /* 11742 ** EXTENSION API FUNCTIONS 11743 ** 11744 ** xUserData(pFts): 11745 ** Return a copy of the context pointer the extension function was 11746 ** registered with. 11747 ** 11748 ** xColumnTotalSize(pFts, iCol, pnToken): 11749 ** If parameter iCol is less than zero, set output variable *pnToken 11750 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11751 ** non-negative but less than the number of columns in the table, return 11752 ** the total number of tokens in column iCol, considering all rows in 11753 ** the FTS5 table. 11754 ** 11755 ** If parameter iCol is greater than or equal to the number of columns 11756 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11757 ** an OOM condition or IO error), an appropriate SQLite error code is 11758 ** returned. 11759 ** 11760 ** xColumnCount(pFts): 11761 ** Return the number of columns in the table. 11762 ** 11763 ** xColumnSize(pFts, iCol, pnToken): 11764 ** If parameter iCol is less than zero, set output variable *pnToken 11765 ** to the total number of tokens in the current row. Or, if iCol is 11766 ** non-negative but less than the number of columns in the table, set 11767 ** *pnToken to the number of tokens in column iCol of the current row. 11768 ** 11769 ** If parameter iCol is greater than or equal to the number of columns 11770 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11771 ** an OOM condition or IO error), an appropriate SQLite error code is 11772 ** returned. 11773 ** 11774 ** This function may be quite inefficient if used with an FTS5 table 11775 ** created with the "columnsize=0" option. 11776 ** 11777 ** xColumnText: 11778 ** This function attempts to retrieve the text of column iCol of the 11779 ** current document. If successful, (*pz) is set to point to a buffer 11780 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11781 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11782 ** if an error occurs, an SQLite error code is returned and the final values 11783 ** of (*pz) and (*pn) are undefined. 11784 ** 11785 ** xPhraseCount: 11786 ** Returns the number of phrases in the current query expression. 11787 ** 11788 ** xPhraseSize: 11789 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11790 ** are numbered starting from zero. 11791 ** 11792 ** xInstCount: 11793 ** Set *pnInst to the total number of occurrences of all phrases within 11794 ** the query within the current row. Return SQLITE_OK if successful, or 11795 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11796 ** 11797 ** This API can be quite slow if used with an FTS5 table created with the 11798 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11799 ** with either "detail=none" or "detail=column" and "content=" option 11800 ** (i.e. if it is a contentless table), then this API always returns 0. 11801 ** 11802 ** xInst: 11803 ** Query for the details of phrase match iIdx within the current row. 11804 ** Phrase matches are numbered starting from zero, so the iIdx argument 11805 ** should be greater than or equal to zero and smaller than the value 11806 ** output by xInstCount(). 11807 ** 11808 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11809 ** to the column in which it occurs and *piOff the token offset of the 11810 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11811 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11812 ** 11813 ** This API can be quite slow if used with an FTS5 table created with the 11814 ** "detail=none" or "detail=column" option. 11815 ** 11816 ** xRowid: 11817 ** Returns the rowid of the current row. 11818 ** 11819 ** xTokenize: 11820 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11821 ** 11822 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11823 ** This API function is used to query the FTS table for phrase iPhrase 11824 ** of the current query. Specifically, a query equivalent to: 11825 ** 11826 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11827 ** 11828 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11829 ** current query is executed. Any column filter that applies to 11830 ** phrase iPhrase of the current query is included in $p. For each 11831 ** row visited, the callback function passed as the fourth argument 11832 ** is invoked. The context and API objects passed to the callback 11833 ** function may be used to access the properties of each matched row. 11834 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11835 ** the third argument to pUserData. 11836 ** 11837 ** If the callback function returns any value other than SQLITE_OK, the 11838 ** query is abandoned and the xQueryPhrase function returns immediately. 11839 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11840 ** Otherwise, the error code is propagated upwards. 11841 ** 11842 ** If the query runs to completion without incident, SQLITE_OK is returned. 11843 ** Or, if some error occurs before the query completes or is aborted by 11844 ** the callback, an SQLite error code is returned. 11845 ** 11846 ** 11847 ** xSetAuxdata(pFts5, pAux, xDelete) 11848 ** 11849 ** Save the pointer passed as the second argument as the extension function's 11850 ** "auxiliary data". The pointer may then be retrieved by the current or any 11851 ** future invocation of the same fts5 extension function made as part of 11852 ** the same MATCH query using the xGetAuxdata() API. 11853 ** 11854 ** Each extension function is allocated a single auxiliary data slot for 11855 ** each FTS query (MATCH expression). If the extension function is invoked 11856 ** more than once for a single FTS query, then all invocations share a 11857 ** single auxiliary data context. 11858 ** 11859 ** If there is already an auxiliary data pointer when this function is 11860 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11861 ** was specified along with the original pointer, it is invoked at this 11862 ** point. 11863 ** 11864 ** The xDelete callback, if one is specified, is also invoked on the 11865 ** auxiliary data pointer after the FTS5 query has finished. 11866 ** 11867 ** If an error (e.g. an OOM condition) occurs within this function, 11868 ** the auxiliary data is set to NULL and an error code returned. If the 11869 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11870 ** pointer before returning. 11871 ** 11872 ** 11873 ** xGetAuxdata(pFts5, bClear) 11874 ** 11875 ** Returns the current auxiliary data pointer for the fts5 extension 11876 ** function. See the xSetAuxdata() method for details. 11877 ** 11878 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11879 ** (set to NULL) before this function returns. In this case the xDelete, 11880 ** if any, is not invoked. 11881 ** 11882 ** 11883 ** xRowCount(pFts5, pnRow) 11884 ** 11885 ** This function is used to retrieve the total number of rows in the table. 11886 ** In other words, the same value that would be returned by: 11887 ** 11888 ** SELECT count(*) FROM ftstable; 11889 ** 11890 ** xPhraseFirst() 11891 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11892 ** method, to iterate through all instances of a single query phrase within 11893 ** the current row. This is the same information as is accessible via the 11894 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11895 ** to use, this API may be faster under some circumstances. To iterate 11896 ** through instances of phrase iPhrase, use the following code: 11897 ** 11898 ** Fts5PhraseIter iter; 11899 ** int iCol, iOff; 11900 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11901 ** iCol>=0; 11902 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11903 ** ){ 11904 ** // An instance of phrase iPhrase at offset iOff of column iCol 11905 ** } 11906 ** 11907 ** The Fts5PhraseIter structure is defined above. Applications should not 11908 ** modify this structure directly - it should only be used as shown above 11909 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11910 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11911 ** 11912 ** This API can be quite slow if used with an FTS5 table created with the 11913 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11914 ** with either "detail=none" or "detail=column" and "content=" option 11915 ** (i.e. if it is a contentless table), then this API always iterates 11916 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11917 ** 11918 ** xPhraseNext() 11919 ** See xPhraseFirst above. 11920 ** 11921 ** xPhraseFirstColumn() 11922 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11923 ** and xPhraseNext() APIs described above. The difference is that instead 11924 ** of iterating through all instances of a phrase in the current row, these 11925 ** APIs are used to iterate through the set of columns in the current row 11926 ** that contain one or more instances of a specified phrase. For example: 11927 ** 11928 ** Fts5PhraseIter iter; 11929 ** int iCol; 11930 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11931 ** iCol>=0; 11932 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11933 ** ){ 11934 ** // Column iCol contains at least one instance of phrase iPhrase 11935 ** } 11936 ** 11937 ** This API can be quite slow if used with an FTS5 table created with the 11938 ** "detail=none" option. If the FTS5 table is created with either 11939 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11940 ** then this API always iterates through an empty set (all calls to 11941 ** xPhraseFirstColumn() set iCol to -1). 11942 ** 11943 ** The information accessed using this API and its companion 11944 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11945 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11946 ** significantly more efficient than those alternatives when used with 11947 ** "detail=column" tables. 11948 ** 11949 ** xPhraseNextColumn() 11950 ** See xPhraseFirstColumn above. 11951 */ 11952 struct Fts5ExtensionApi { 11953 int iVersion; /* Currently always set to 3 */ 11954 11955 void *(*xUserData)(Fts5Context*); 11956 11957 int (*xColumnCount)(Fts5Context*); 11958 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11959 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11960 11961 int (*xTokenize)(Fts5Context*, 11962 const char *pText, int nText, /* Text to tokenize */ 11963 void *pCtx, /* Context passed to xToken() */ 11964 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11965 ); 11966 11967 int (*xPhraseCount)(Fts5Context*); 11968 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11969 11970 int (*xInstCount)(Fts5Context*, int *pnInst); 11971 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11972 11973 sqlite3_int64 (*xRowid)(Fts5Context*); 11974 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11975 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11976 11977 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11978 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11979 ); 11980 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11981 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11982 11983 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11984 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11985 11986 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11987 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11988 }; 11989 11990 /* 11991 ** CUSTOM AUXILIARY FUNCTIONS 11992 *************************************************************************/ 11993 11994 /************************************************************************* 11995 ** CUSTOM TOKENIZERS 11996 ** 11997 ** Applications may also register custom tokenizer types. A tokenizer 11998 ** is registered by providing fts5 with a populated instance of the 11999 ** following structure. All structure methods must be defined, setting 12000 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12001 ** behaviour. The structure methods are expected to function as follows: 12002 ** 12003 ** xCreate: 12004 ** This function is used to allocate and initialize a tokenizer instance. 12005 ** A tokenizer instance is required to actually tokenize text. 12006 ** 12007 ** The first argument passed to this function is a copy of the (void*) 12008 ** pointer provided by the application when the fts5_tokenizer object 12009 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 12010 ** The second and third arguments are an array of nul-terminated strings 12011 ** containing the tokenizer arguments, if any, specified following the 12012 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12013 ** to create the FTS5 table. 12014 ** 12015 ** The final argument is an output variable. If successful, (*ppOut) 12016 ** should be set to point to the new tokenizer handle and SQLITE_OK 12017 ** returned. If an error occurs, some value other than SQLITE_OK should 12018 ** be returned. In this case, fts5 assumes that the final value of *ppOut 12019 ** is undefined. 12020 ** 12021 ** xDelete: 12022 ** This function is invoked to delete a tokenizer handle previously 12023 ** allocated using xCreate(). Fts5 guarantees that this function will 12024 ** be invoked exactly once for each successful call to xCreate(). 12025 ** 12026 ** xTokenize: 12027 ** This function is expected to tokenize the nText byte string indicated 12028 ** by argument pText. pText may or may not be nul-terminated. The first 12029 ** argument passed to this function is a pointer to an Fts5Tokenizer object 12030 ** returned by an earlier call to xCreate(). 12031 ** 12032 ** The second argument indicates the reason that FTS5 is requesting 12033 ** tokenization of the supplied text. This is always one of the following 12034 ** four values: 12035 ** 12036 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12037 ** or removed from the FTS table. The tokenizer is being invoked to 12038 ** determine the set of tokens to add to (or delete from) the 12039 ** FTS index. 12040 ** 12041 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12042 ** against the FTS index. The tokenizer is being called to tokenize 12043 ** a bareword or quoted string specified as part of the query. 12044 ** 12045 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12046 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12047 ** followed by a "*" character, indicating that the last token 12048 ** returned by the tokenizer will be treated as a token prefix. 12049 ** 12050 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12051 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12052 ** function. Or an fts5_api.xColumnSize() request made by the same 12053 ** on a columnsize=0 database. 12054 ** </ul> 12055 ** 12056 ** For each token in the input string, the supplied callback xToken() must 12057 ** be invoked. The first argument to it should be a copy of the pointer 12058 ** passed as the second argument to xTokenize(). The third and fourth 12059 ** arguments are a pointer to a buffer containing the token text, and the 12060 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12061 ** of the first byte of and first byte immediately following the text from 12062 ** which the token is derived within the input. 12063 ** 12064 ** The second argument passed to the xToken() callback ("tflags") should 12065 ** normally be set to 0. The exception is if the tokenizer supports 12066 ** synonyms. In this case see the discussion below for details. 12067 ** 12068 ** FTS5 assumes the xToken() callback is invoked for each token in the 12069 ** order that they occur within the input text. 12070 ** 12071 ** If an xToken() callback returns any value other than SQLITE_OK, then 12072 ** the tokenization should be abandoned and the xTokenize() method should 12073 ** immediately return a copy of the xToken() return value. Or, if the 12074 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12075 ** if an error occurs with the xTokenize() implementation itself, it 12076 ** may abandon the tokenization and return any error code other than 12077 ** SQLITE_OK or SQLITE_DONE. 12078 ** 12079 ** SYNONYM SUPPORT 12080 ** 12081 ** Custom tokenizers may also support synonyms. Consider a case in which a 12082 ** user wishes to query for a phrase such as "first place". Using the 12083 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 12084 ** of "first place" within the document set, but not alternative forms 12085 ** such as "1st place". In some applications, it would be better to match 12086 ** all instances of "first place" or "1st place" regardless of which form 12087 ** the user specified in the MATCH query text. 12088 ** 12089 ** There are several ways to approach this in FTS5: 12090 ** 12091 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12092 ** the above example, this means that the tokenizer returns the 12093 ** same token for inputs "first" and "1st". Say that token is in 12094 ** fact "first", so that when the user inserts the document "I won 12095 ** 1st place" entries are added to the index for tokens "i", "won", 12096 ** "first" and "place". If the user then queries for '1st + place', 12097 ** the tokenizer substitutes "first" for "1st" and the query works 12098 ** as expected. 12099 ** 12100 ** <li> By querying the index for all synonyms of each query term 12101 ** separately. In this case, when tokenizing query text, the 12102 ** tokenizer may provide multiple synonyms for a single term 12103 ** within the document. FTS5 then queries the index for each 12104 ** synonym individually. For example, faced with the query: 12105 ** 12106 ** <codeblock> 12107 ** ... MATCH 'first place'</codeblock> 12108 ** 12109 ** the tokenizer offers both "1st" and "first" as synonyms for the 12110 ** first token in the MATCH query and FTS5 effectively runs a query 12111 ** similar to: 12112 ** 12113 ** <codeblock> 12114 ** ... MATCH '(first OR 1st) place'</codeblock> 12115 ** 12116 ** except that, for the purposes of auxiliary functions, the query 12117 ** still appears to contain just two phrases - "(first OR 1st)" 12118 ** being treated as a single phrase. 12119 ** 12120 ** <li> By adding multiple synonyms for a single term to the FTS index. 12121 ** Using this method, when tokenizing document text, the tokenizer 12122 ** provides multiple synonyms for each token. So that when a 12123 ** document such as "I won first place" is tokenized, entries are 12124 ** added to the FTS index for "i", "won", "first", "1st" and 12125 ** "place". 12126 ** 12127 ** This way, even if the tokenizer does not provide synonyms 12128 ** when tokenizing query text (it should not - to do so would be 12129 ** inefficient), it doesn't matter if the user queries for 12130 ** 'first + place' or '1st + place', as there are entries in the 12131 ** FTS index corresponding to both forms of the first token. 12132 ** </ol> 12133 ** 12134 ** Whether it is parsing document or query text, any call to xToken that 12135 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12136 ** is considered to supply a synonym for the previous token. For example, 12137 ** when parsing the document "I won first place", a tokenizer that supports 12138 ** synonyms would call xToken() 5 times, as follows: 12139 ** 12140 ** <codeblock> 12141 ** xToken(pCtx, 0, "i", 1, 0, 1); 12142 ** xToken(pCtx, 0, "won", 3, 2, 5); 12143 ** xToken(pCtx, 0, "first", 5, 6, 11); 12144 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12145 ** xToken(pCtx, 0, "place", 5, 12, 17); 12146 **</codeblock> 12147 ** 12148 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12149 ** xToken() is called. Multiple synonyms may be specified for a single token 12150 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12151 ** There is no limit to the number of synonyms that may be provided for a 12152 ** single token. 12153 ** 12154 ** In many cases, method (1) above is the best approach. It does not add 12155 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12156 ** so it is efficient in terms of disk space and query speed. However, it 12157 ** does not support prefix queries very well. If, as suggested above, the 12158 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12159 ** 12160 ** <codeblock> 12161 ** ... MATCH '1s*'</codeblock> 12162 ** 12163 ** will not match documents that contain the token "1st" (as the tokenizer 12164 ** will probably not map "1s" to any prefix of "first"). 12165 ** 12166 ** For full prefix support, method (3) may be preferred. In this case, 12167 ** because the index contains entries for both "first" and "1st", prefix 12168 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12169 ** extra entries are added to the FTS index, this method uses more space 12170 ** within the database. 12171 ** 12172 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12173 ** a query such as '1s*' will match documents that contain the literal 12174 ** token "1st", but not "first" (assuming the tokenizer is not able to 12175 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12176 ** will match against "1st" and "first". This method does not require 12177 ** extra disk space, as no extra entries are added to the FTS index. 12178 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12179 ** as separate queries of the FTS index are required for each synonym. 12180 ** 12181 ** When using methods (2) or (3), it is important that the tokenizer only 12182 ** provide synonyms when tokenizing document text (method (2)) or query 12183 ** text (method (3)), not both. Doing so will not cause any errors, but is 12184 ** inefficient. 12185 */ 12186 typedef struct Fts5Tokenizer Fts5Tokenizer; 12187 typedef struct fts5_tokenizer fts5_tokenizer; 12188 struct fts5_tokenizer { 12189 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12190 void (*xDelete)(Fts5Tokenizer*); 12191 int (*xTokenize)(Fts5Tokenizer*, 12192 void *pCtx, 12193 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12194 const char *pText, int nText, 12195 int (*xToken)( 12196 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12197 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12198 const char *pToken, /* Pointer to buffer containing token */ 12199 int nToken, /* Size of token in bytes */ 12200 int iStart, /* Byte offset of token within input text */ 12201 int iEnd /* Byte offset of end of token within input text */ 12202 ) 12203 ); 12204 }; 12205 12206 /* Flags that may be passed as the third argument to xTokenize() */ 12207 #define FTS5_TOKENIZE_QUERY 0x0001 12208 #define FTS5_TOKENIZE_PREFIX 0x0002 12209 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12210 #define FTS5_TOKENIZE_AUX 0x0008 12211 12212 /* Flags that may be passed by the tokenizer implementation back to FTS5 12213 ** as the third argument to the supplied xToken callback. */ 12214 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12215 12216 /* 12217 ** END OF CUSTOM TOKENIZERS 12218 *************************************************************************/ 12219 12220 /************************************************************************* 12221 ** FTS5 EXTENSION REGISTRATION API 12222 */ 12223 typedef struct fts5_api fts5_api; 12224 struct fts5_api { 12225 int iVersion; /* Currently always set to 2 */ 12226 12227 /* Create a new tokenizer */ 12228 int (*xCreateTokenizer)( 12229 fts5_api *pApi, 12230 const char *zName, 12231 void *pContext, 12232 fts5_tokenizer *pTokenizer, 12233 void (*xDestroy)(void*) 12234 ); 12235 12236 /* Find an existing tokenizer */ 12237 int (*xFindTokenizer)( 12238 fts5_api *pApi, 12239 const char *zName, 12240 void **ppContext, 12241 fts5_tokenizer *pTokenizer 12242 ); 12243 12244 /* Create a new auxiliary function */ 12245 int (*xCreateFunction)( 12246 fts5_api *pApi, 12247 const char *zName, 12248 void *pContext, 12249 fts5_extension_function xFunction, 12250 void (*xDestroy)(void*) 12251 ); 12252 }; 12253 12254 /* 12255 ** END OF REGISTRATION API 12256 *************************************************************************/ 12257 12258 #ifdef __cplusplus 12259 } /* end of the 'extern "C"' block */ 12260 #endif 12261 12262 #endif /* _FTS5_H */ 12263 12264 /******** End of fts5.h *********/ 12265