1 /* 2 ** 2001 September 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 an SHA1 118 ** hash of the entire source tree. 119 ** 120 ** See also: [sqlite3_libversion()], 121 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 122 ** [sqlite_version()] and [sqlite_source_id()]. 123 */ 124 #define SQLITE_VERSION "3.16.2" 125 #define SQLITE_VERSION_NUMBER 3016002 126 #define SQLITE_SOURCE_ID "2017-01-06 16:32:41 a65a62893ca8319e89e48b8a38cf8a59c69a8209" 127 128 /* 129 ** CAPI3REF: Run-Time Library Version Numbers 130 ** KEYWORDS: sqlite3_version sqlite3_sourceid 131 ** 132 ** These interfaces provide the same information as the [SQLITE_VERSION], 133 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 134 ** but are associated with the library instead of the header file. ^(Cautious 135 ** programmers might include assert() statements in their application to 136 ** verify that values returned by these interfaces match the macros in 137 ** the header, and thus ensure that the application is 138 ** compiled with matching library and header files. 139 ** 140 ** <blockquote><pre> 141 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 142 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 143 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 144 ** </pre></blockquote>)^ 145 ** 146 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 147 ** macro. ^The sqlite3_libversion() function returns a pointer to the 148 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 149 ** function is provided for use in DLLs since DLL users usually do not have 150 ** direct access to string constants within the DLL. ^The 151 ** sqlite3_libversion_number() function returns an integer equal to 152 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 153 ** a pointer to a string constant whose value is the same as the 154 ** [SQLITE_SOURCE_ID] C preprocessor macro. 155 ** 156 ** See also: [sqlite_version()] and [sqlite_source_id()]. 157 */ 158 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 159 SQLITE_API const char *sqlite3_libversion(void); 160 SQLITE_API const char *sqlite3_sourceid(void); 161 SQLITE_API int sqlite3_libversion_number(void); 162 163 /* 164 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 165 ** 166 ** ^The sqlite3_compileoption_used() function returns 0 or 1 167 ** indicating whether the specified option was defined at 168 ** compile time. ^The SQLITE_ prefix may be omitted from the 169 ** option name passed to sqlite3_compileoption_used(). 170 ** 171 ** ^The sqlite3_compileoption_get() function allows iterating 172 ** over the list of options that were defined at compile time by 173 ** returning the N-th compile time option string. ^If N is out of range, 174 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 175 ** prefix is omitted from any strings returned by 176 ** sqlite3_compileoption_get(). 177 ** 178 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 179 ** and sqlite3_compileoption_get() may be omitted by specifying the 180 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 181 ** 182 ** See also: SQL functions [sqlite_compileoption_used()] and 183 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 184 */ 185 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 186 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 187 SQLITE_API const char *sqlite3_compileoption_get(int N); 188 #endif 189 190 /* 191 ** CAPI3REF: Test To See If The Library Is Threadsafe 192 ** 193 ** ^The sqlite3_threadsafe() function returns zero if and only if 194 ** SQLite was compiled with mutexing code omitted due to the 195 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 196 ** 197 ** SQLite can be compiled with or without mutexes. When 198 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 199 ** are enabled and SQLite is threadsafe. When the 200 ** [SQLITE_THREADSAFE] macro is 0, 201 ** the mutexes are omitted. Without the mutexes, it is not safe 202 ** to use SQLite concurrently from more than one thread. 203 ** 204 ** Enabling mutexes incurs a measurable performance penalty. 205 ** So if speed is of utmost importance, it makes sense to disable 206 ** the mutexes. But for maximum safety, mutexes should be enabled. 207 ** ^The default behavior is for mutexes to be enabled. 208 ** 209 ** This interface can be used by an application to make sure that the 210 ** version of SQLite that it is linking against was compiled with 211 ** the desired setting of the [SQLITE_THREADSAFE] macro. 212 ** 213 ** This interface only reports on the compile-time mutex setting 214 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 215 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 216 ** can be fully or partially disabled using a call to [sqlite3_config()] 217 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 218 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 219 ** sqlite3_threadsafe() function shows only the compile-time setting of 220 ** thread safety, not any run-time changes to that setting made by 221 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 222 ** is unchanged by calls to sqlite3_config().)^ 223 ** 224 ** See the [threading mode] documentation for additional information. 225 */ 226 SQLITE_API int sqlite3_threadsafe(void); 227 228 /* 229 ** CAPI3REF: Database Connection Handle 230 ** KEYWORDS: {database connection} {database connections} 231 ** 232 ** Each open SQLite database is represented by a pointer to an instance of 233 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 234 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 235 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 236 ** and [sqlite3_close_v2()] are its destructors. There are many other 237 ** interfaces (such as 238 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 239 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 240 ** sqlite3 object. 241 */ 242 typedef struct sqlite3 sqlite3; 243 244 /* 245 ** CAPI3REF: 64-Bit Integer Types 246 ** KEYWORDS: sqlite_int64 sqlite_uint64 247 ** 248 ** Because there is no cross-platform way to specify 64-bit integer types 249 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 250 ** 251 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 252 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 253 ** compatibility only. 254 ** 255 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 256 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 257 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 258 ** between 0 and +18446744073709551615 inclusive. 259 */ 260 #ifdef SQLITE_INT64_TYPE 261 typedef SQLITE_INT64_TYPE sqlite_int64; 262 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 263 #elif defined(_MSC_VER) || defined(__BORLANDC__) 264 typedef __int64 sqlite_int64; 265 typedef unsigned __int64 sqlite_uint64; 266 #else 267 typedef long long int sqlite_int64; 268 typedef unsigned long long int sqlite_uint64; 269 #endif 270 typedef sqlite_int64 sqlite3_int64; 271 typedef sqlite_uint64 sqlite3_uint64; 272 273 /* 274 ** If compiling for a processor that lacks floating point support, 275 ** substitute integer for floating-point. 276 */ 277 #ifdef SQLITE_OMIT_FLOATING_POINT 278 # define double sqlite3_int64 279 #endif 280 281 /* 282 ** CAPI3REF: Closing A Database Connection 283 ** DESTRUCTOR: sqlite3 284 ** 285 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 286 ** for the [sqlite3] object. 287 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 288 ** the [sqlite3] object is successfully destroyed and all associated 289 ** resources are deallocated. 290 ** 291 ** ^If the database connection is associated with unfinalized prepared 292 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 293 ** will leave the database connection open and return [SQLITE_BUSY]. 294 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 295 ** and/or unfinished sqlite3_backups, then the database connection becomes 296 ** an unusable "zombie" which will automatically be deallocated when the 297 ** last prepared statement is finalized or the last sqlite3_backup is 298 ** finished. The sqlite3_close_v2() interface is intended for use with 299 ** host languages that are garbage collected, and where the order in which 300 ** destructors are called is arbitrary. 301 ** 302 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 303 ** [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. ^If 306 ** sqlite3_close_v2() is called on a [database connection] that still has 307 ** outstanding [prepared statements], [BLOB handles], and/or 308 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 309 ** of resources is deferred until all [prepared statements], [BLOB handles], 310 ** and [sqlite3_backup] objects are also destroyed. 311 ** 312 ** ^If an [sqlite3] object is destroyed while a transaction is open, 313 ** the transaction is automatically rolled back. 314 ** 315 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 316 ** must be either a NULL 317 ** pointer or an [sqlite3] object pointer obtained 318 ** from [sqlite3_open()], [sqlite3_open16()], or 319 ** [sqlite3_open_v2()], and not previously closed. 320 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 321 ** argument is a harmless no-op. 322 */ 323 SQLITE_API int sqlite3_close(sqlite3*); 324 SQLITE_API int sqlite3_close_v2(sqlite3*); 325 326 /* 327 ** The type for a callback function. 328 ** This is legacy and deprecated. It is included for historical 329 ** compatibility and is not documented. 330 */ 331 typedef int (*sqlite3_callback)(void*,int,char**, char**); 332 333 /* 334 ** CAPI3REF: One-Step Query Execution Interface 335 ** METHOD: sqlite3 336 ** 337 ** The sqlite3_exec() interface is a convenience wrapper around 338 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 339 ** that allows an application to run multiple statements of SQL 340 ** without having to use a lot of C code. 341 ** 342 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 343 ** semicolon-separate SQL statements passed into its 2nd argument, 344 ** in the context of the [database connection] passed in as its 1st 345 ** argument. ^If the callback function of the 3rd argument to 346 ** sqlite3_exec() is not NULL, then it is invoked for each result row 347 ** coming out of the evaluated SQL statements. ^The 4th argument to 348 ** sqlite3_exec() is relayed through to the 1st argument of each 349 ** callback invocation. ^If the callback pointer to sqlite3_exec() 350 ** is NULL, then no callback is ever invoked and result rows are 351 ** ignored. 352 ** 353 ** ^If an error occurs while evaluating the SQL statements passed into 354 ** sqlite3_exec(), then execution of the current statement stops and 355 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 356 ** is not NULL then any error message is written into memory obtained 357 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 358 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 359 ** on error message strings returned through the 5th parameter of 360 ** sqlite3_exec() after the error message string is no longer needed. 361 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 362 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 363 ** NULL before returning. 364 ** 365 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 366 ** routine returns SQLITE_ABORT without invoking the callback again and 367 ** without running any subsequent SQL statements. 368 ** 369 ** ^The 2nd argument to the sqlite3_exec() callback function is the 370 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 371 ** callback is an array of pointers to strings obtained as if from 372 ** [sqlite3_column_text()], one for each column. ^If an element of a 373 ** result row is NULL then the corresponding string pointer for the 374 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 375 ** sqlite3_exec() callback is an array of pointers to strings where each 376 ** entry represents the name of corresponding result column as obtained 377 ** from [sqlite3_column_name()]. 378 ** 379 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 380 ** to an empty string, or a pointer that contains only whitespace and/or 381 ** SQL comments, then no SQL statements are evaluated and the database 382 ** is not changed. 383 ** 384 ** Restrictions: 385 ** 386 ** <ul> 387 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 388 ** is a valid and open [database connection]. 389 ** <li> The application must not close the [database connection] specified by 390 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 391 ** <li> The application must not modify the SQL statement text passed into 392 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 393 ** </ul> 394 */ 395 SQLITE_API int sqlite3_exec( 396 sqlite3*, /* An open database */ 397 const char *sql, /* SQL to be evaluated */ 398 int (*callback)(void*,int,char**,char**), /* Callback function */ 399 void *, /* 1st argument to callback */ 400 char **errmsg /* Error msg written here */ 401 ); 402 403 /* 404 ** CAPI3REF: Result Codes 405 ** KEYWORDS: {result code definitions} 406 ** 407 ** Many SQLite functions return an integer result code from the set shown 408 ** here in order to indicate success or failure. 409 ** 410 ** New error codes may be added in future versions of SQLite. 411 ** 412 ** See also: [extended result code definitions] 413 */ 414 #define SQLITE_OK 0 /* Successful result */ 415 /* beginning-of-error-codes */ 416 #define SQLITE_ERROR 1 /* SQL error or missing database */ 417 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 418 #define SQLITE_PERM 3 /* Access permission denied */ 419 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 420 #define SQLITE_BUSY 5 /* The database file is locked */ 421 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 422 #define SQLITE_NOMEM 7 /* A malloc() failed */ 423 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 424 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 425 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 426 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 427 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 428 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 429 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 430 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 431 #define SQLITE_EMPTY 16 /* Database is empty */ 432 #define SQLITE_SCHEMA 17 /* The database schema changed */ 433 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 434 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 435 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 436 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 437 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 438 #define SQLITE_AUTH 23 /* Authorization denied */ 439 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 440 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 441 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 442 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 443 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 444 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 445 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 446 /* end-of-error-codes */ 447 448 /* 449 ** CAPI3REF: Extended Result Codes 450 ** KEYWORDS: {extended result code definitions} 451 ** 452 ** In its default configuration, SQLite API routines return one of 30 integer 453 ** [result codes]. However, experience has shown that many of 454 ** these result codes are too coarse-grained. They do not provide as 455 ** much information about problems as programmers might like. In an effort to 456 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 457 ** and later) include 458 ** support for additional result codes that provide more detailed information 459 ** about errors. These [extended result codes] are enabled or disabled 460 ** on a per database connection basis using the 461 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 462 ** the most recent error can be obtained using 463 ** [sqlite3_extended_errcode()]. 464 */ 465 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 466 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 467 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 468 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 469 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 470 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 471 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 472 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 473 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 474 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 475 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 476 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 477 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 478 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 479 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 480 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 481 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 482 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 483 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 484 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 485 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 486 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 487 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 488 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 489 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 490 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 491 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 492 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 493 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 494 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 495 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 496 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 497 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 498 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 499 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 500 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 501 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 502 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 503 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 504 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 505 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 506 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 507 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 508 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 509 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 510 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 511 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 512 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 513 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 514 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 515 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 516 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 517 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 518 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 519 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 520 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 521 522 /* 523 ** CAPI3REF: Flags For File Open Operations 524 ** 525 ** These bit values are intended for use in the 526 ** 3rd parameter to the [sqlite3_open_v2()] interface and 527 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 528 */ 529 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 530 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 531 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 532 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 533 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 534 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 535 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 536 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 537 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 538 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 539 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 540 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 541 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 542 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 543 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 544 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 545 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 546 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 547 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 548 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 549 550 /* Reserved: 0x00F00000 */ 551 552 /* 553 ** CAPI3REF: Device Characteristics 554 ** 555 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 556 ** object returns an integer which is a vector of these 557 ** bit values expressing I/O characteristics of the mass storage 558 ** device that holds the file that the [sqlite3_io_methods] 559 ** refers to. 560 ** 561 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 562 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 563 ** mean that writes of blocks that are nnn bytes in size and 564 ** are aligned to an address which is an integer multiple of 565 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 566 ** that when data is appended to a file, the data is appended 567 ** first then the size of the file is extended, never the other 568 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 569 ** information is written to disk in the same order as calls 570 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 571 ** after reboot following a crash or power loss, the only bytes in a 572 ** file that were written at the application level might have changed 573 ** and that adjacent bytes, even bytes within the same sector are 574 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 575 ** flag indicate that a file cannot be deleted when open. The 576 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 577 ** read-only media and cannot be changed even by processes with 578 ** elevated privileges. 579 */ 580 #define SQLITE_IOCAP_ATOMIC 0x00000001 581 #define SQLITE_IOCAP_ATOMIC512 0x00000002 582 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 583 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 584 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 585 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 586 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 587 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 588 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 589 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 590 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 591 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 592 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 593 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 594 595 /* 596 ** CAPI3REF: File Locking Levels 597 ** 598 ** SQLite uses one of these integer values as the second 599 ** argument to calls it makes to the xLock() and xUnlock() methods 600 ** of an [sqlite3_io_methods] object. 601 */ 602 #define SQLITE_LOCK_NONE 0 603 #define SQLITE_LOCK_SHARED 1 604 #define SQLITE_LOCK_RESERVED 2 605 #define SQLITE_LOCK_PENDING 3 606 #define SQLITE_LOCK_EXCLUSIVE 4 607 608 /* 609 ** CAPI3REF: Synchronization Type Flags 610 ** 611 ** When SQLite invokes the xSync() method of an 612 ** [sqlite3_io_methods] object it uses a combination of 613 ** these integer values as the second argument. 614 ** 615 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 616 ** sync operation only needs to flush data to mass storage. Inode 617 ** information need not be flushed. If the lower four bits of the flag 618 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 619 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 620 ** to use Mac OS X style fullsync instead of fsync(). 621 ** 622 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 623 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 624 ** settings. The [synchronous pragma] determines when calls to the 625 ** xSync VFS method occur and applies uniformly across all platforms. 626 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 627 ** energetic or rigorous or forceful the sync operations are and 628 ** only make a difference on Mac OSX for the default SQLite code. 629 ** (Third-party VFS implementations might also make the distinction 630 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 631 ** operating systems natively supported by SQLite, only Mac OSX 632 ** cares about the difference.) 633 */ 634 #define SQLITE_SYNC_NORMAL 0x00002 635 #define SQLITE_SYNC_FULL 0x00003 636 #define SQLITE_SYNC_DATAONLY 0x00010 637 638 /* 639 ** CAPI3REF: OS Interface Open File Handle 640 ** 641 ** An [sqlite3_file] object represents an open file in the 642 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 643 ** implementations will 644 ** want to subclass this object by appending additional fields 645 ** for their own use. The pMethods entry is a pointer to an 646 ** [sqlite3_io_methods] object that defines methods for performing 647 ** I/O operations on the open file. 648 */ 649 typedef struct sqlite3_file sqlite3_file; 650 struct sqlite3_file { 651 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 652 }; 653 654 /* 655 ** CAPI3REF: OS Interface File Virtual Methods Object 656 ** 657 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 658 ** [sqlite3_file] object (or, more commonly, a subclass of the 659 ** [sqlite3_file] object) with a pointer to an instance of this object. 660 ** This object defines the methods used to perform various operations 661 ** against the open file represented by the [sqlite3_file] object. 662 ** 663 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 664 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 665 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 666 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 667 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 668 ** to NULL. 669 ** 670 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 671 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 672 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 673 ** flag may be ORed in to indicate that only the data of the file 674 ** and not its inode needs to be synced. 675 ** 676 ** The integer values to xLock() and xUnlock() are one of 677 ** <ul> 678 ** <li> [SQLITE_LOCK_NONE], 679 ** <li> [SQLITE_LOCK_SHARED], 680 ** <li> [SQLITE_LOCK_RESERVED], 681 ** <li> [SQLITE_LOCK_PENDING], or 682 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 683 ** </ul> 684 ** xLock() increases the lock. xUnlock() decreases the lock. 685 ** The xCheckReservedLock() method checks whether any database connection, 686 ** either in this process or in some other process, is holding a RESERVED, 687 ** PENDING, or EXCLUSIVE lock on the file. It returns true 688 ** if such a lock exists and false otherwise. 689 ** 690 ** The xFileControl() method is a generic interface that allows custom 691 ** VFS implementations to directly control an open file using the 692 ** [sqlite3_file_control()] interface. The second "op" argument is an 693 ** integer opcode. The third argument is a generic pointer intended to 694 ** point to a structure that may contain arguments or space in which to 695 ** write return values. Potential uses for xFileControl() might be 696 ** functions to enable blocking locks with timeouts, to change the 697 ** locking strategy (for example to use dot-file locks), to inquire 698 ** about the status of a lock, or to break stale locks. The SQLite 699 ** core reserves all opcodes less than 100 for its own use. 700 ** A [file control opcodes | list of opcodes] less than 100 is available. 701 ** Applications that define a custom xFileControl method should use opcodes 702 ** greater than 100 to avoid conflicts. VFS implementations should 703 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 704 ** recognize. 705 ** 706 ** The xSectorSize() method returns the sector size of the 707 ** device that underlies the file. The sector size is the 708 ** minimum write that can be performed without disturbing 709 ** other bytes in the file. The xDeviceCharacteristics() 710 ** method returns a bit vector describing behaviors of the 711 ** underlying device: 712 ** 713 ** <ul> 714 ** <li> [SQLITE_IOCAP_ATOMIC] 715 ** <li> [SQLITE_IOCAP_ATOMIC512] 716 ** <li> [SQLITE_IOCAP_ATOMIC1K] 717 ** <li> [SQLITE_IOCAP_ATOMIC2K] 718 ** <li> [SQLITE_IOCAP_ATOMIC4K] 719 ** <li> [SQLITE_IOCAP_ATOMIC8K] 720 ** <li> [SQLITE_IOCAP_ATOMIC16K] 721 ** <li> [SQLITE_IOCAP_ATOMIC32K] 722 ** <li> [SQLITE_IOCAP_ATOMIC64K] 723 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 724 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 725 ** </ul> 726 ** 727 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 728 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 729 ** mean that writes of blocks that are nnn bytes in size and 730 ** are aligned to an address which is an integer multiple of 731 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 732 ** that when data is appended to a file, the data is appended 733 ** first then the size of the file is extended, never the other 734 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 735 ** information is written to disk in the same order as calls 736 ** to xWrite(). 737 ** 738 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 739 ** in the unread portions of the buffer with zeros. A VFS that 740 ** fails to zero-fill short reads might seem to work. However, 741 ** failure to zero-fill short reads will eventually lead to 742 ** database corruption. 743 */ 744 typedef struct sqlite3_io_methods sqlite3_io_methods; 745 struct sqlite3_io_methods { 746 int iVersion; 747 int (*xClose)(sqlite3_file*); 748 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 749 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 750 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 751 int (*xSync)(sqlite3_file*, int flags); 752 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 753 int (*xLock)(sqlite3_file*, int); 754 int (*xUnlock)(sqlite3_file*, int); 755 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 756 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 757 int (*xSectorSize)(sqlite3_file*); 758 int (*xDeviceCharacteristics)(sqlite3_file*); 759 /* Methods above are valid for version 1 */ 760 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 761 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 762 void (*xShmBarrier)(sqlite3_file*); 763 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 764 /* Methods above are valid for version 2 */ 765 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 766 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 767 /* Methods above are valid for version 3 */ 768 /* Additional methods may be added in future releases */ 769 }; 770 771 /* 772 ** CAPI3REF: Standard File Control Opcodes 773 ** KEYWORDS: {file control opcodes} {file control opcode} 774 ** 775 ** These integer constants are opcodes for the xFileControl method 776 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 777 ** interface. 778 ** 779 ** <ul> 780 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 781 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 782 ** opcode causes the xFileControl method to write the current state of 783 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 784 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 785 ** into an integer that the pArg argument points to. This capability 786 ** is used during testing and is only available when the SQLITE_TEST 787 ** compile-time option is used. 788 ** 789 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 790 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 791 ** layer a hint of how large the database file will grow to be during the 792 ** current transaction. This hint is not guaranteed to be accurate but it 793 ** is often close. The underlying VFS might choose to preallocate database 794 ** file space based on this hint in order to help writes to the database 795 ** file run faster. 796 ** 797 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 798 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 799 ** extends and truncates the database file in chunks of a size specified 800 ** by the user. The fourth argument to [sqlite3_file_control()] should 801 ** point to an integer (type int) containing the new chunk-size to use 802 ** for the nominated database. Allocating database file space in large 803 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 804 ** improve performance on some systems. 805 ** 806 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 807 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 808 ** to the [sqlite3_file] object associated with a particular database 809 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 810 ** 811 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 812 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 813 ** to the [sqlite3_file] object associated with the journal file (either 814 ** the [rollback journal] or the [write-ahead log]) for a particular database 815 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 816 ** 817 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 818 ** No longer in use. 819 ** 820 ** <li>[[SQLITE_FCNTL_SYNC]] 821 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 822 ** sent to the VFS immediately before the xSync method is invoked on a 823 ** database file descriptor. Or, if the xSync method is not invoked 824 ** because the user has configured SQLite with 825 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 826 ** of the xSync method. In most cases, the pointer argument passed with 827 ** this file-control is NULL. However, if the database file is being synced 828 ** as part of a multi-database commit, the argument points to a nul-terminated 829 ** string containing the transactions master-journal file name. VFSes that 830 ** do not need this signal should silently ignore this opcode. Applications 831 ** should not call [sqlite3_file_control()] with this opcode as doing so may 832 ** disrupt the operation of the specialized VFSes that do require it. 833 ** 834 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 835 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 836 ** and sent to the VFS after a transaction has been committed immediately 837 ** but before the database is unlocked. VFSes that do not need this signal 838 ** should silently ignore this opcode. Applications should not call 839 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 840 ** operation of the specialized VFSes that do require it. 841 ** 842 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 843 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 844 ** retry counts and intervals for certain disk I/O operations for the 845 ** windows [VFS] in order to provide robustness in the presence of 846 ** anti-virus programs. By default, the windows VFS will retry file read, 847 ** file write, and file delete operations up to 10 times, with a delay 848 ** of 25 milliseconds before the first retry and with the delay increasing 849 ** by an additional 25 milliseconds with each subsequent retry. This 850 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 851 ** to be adjusted. The values are changed for all database connections 852 ** within the same process. The argument is a pointer to an array of two 853 ** integers where the first integer i the new retry count and the second 854 ** integer is the delay. If either integer is negative, then the setting 855 ** is not changed but instead the prior value of that setting is written 856 ** into the array entry, allowing the current retry settings to be 857 ** interrogated. The zDbName parameter is ignored. 858 ** 859 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 860 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 861 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 862 ** write ahead log and shared memory files used for transaction control 863 ** are automatically deleted when the latest connection to the database 864 ** closes. Setting persistent WAL mode causes those files to persist after 865 ** close. Persisting the files is useful when other processes that do not 866 ** have write permission on the directory containing the database file want 867 ** to read the database file, as the WAL and shared memory files must exist 868 ** in order for the database to be readable. The fourth parameter to 869 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 870 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 871 ** WAL mode. If the integer is -1, then it is overwritten with the current 872 ** WAL persistence setting. 873 ** 874 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 875 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 876 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 877 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 878 ** xDeviceCharacteristics methods. The fourth parameter to 879 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 880 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 881 ** mode. If the integer is -1, then it is overwritten with the current 882 ** zero-damage mode setting. 883 ** 884 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 885 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 886 ** a write transaction to indicate that, unless it is rolled back for some 887 ** reason, the entire database file will be overwritten by the current 888 ** transaction. This is used by VACUUM operations. 889 ** 890 ** <li>[[SQLITE_FCNTL_VFSNAME]] 891 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 892 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 893 ** final bottom-level VFS are written into memory obtained from 894 ** [sqlite3_malloc()] and the result is stored in the char* variable 895 ** that the fourth parameter of [sqlite3_file_control()] points to. 896 ** The caller is responsible for freeing the memory when done. As with 897 ** all file-control actions, there is no guarantee that this will actually 898 ** do anything. Callers should initialize the char* variable to a NULL 899 ** pointer in case this file-control is not implemented. This file-control 900 ** is intended for diagnostic use only. 901 ** 902 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 903 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 904 ** [VFSes] currently in use. ^(The argument X in 905 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 906 ** of type "[sqlite3_vfs] **". This opcodes will set *X 907 ** to a pointer to the top-level VFS.)^ 908 ** ^When there are multiple VFS shims in the stack, this opcode finds the 909 ** upper-most shim only. 910 ** 911 ** <li>[[SQLITE_FCNTL_PRAGMA]] 912 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 913 ** file control is sent to the open [sqlite3_file] object corresponding 914 ** to the database file to which the pragma statement refers. ^The argument 915 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 916 ** pointers to strings (char**) in which the second element of the array 917 ** is the name of the pragma and the third element is the argument to the 918 ** pragma or NULL if the pragma has no argument. ^The handler for an 919 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 920 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 921 ** or the equivalent and that string will become the result of the pragma or 922 ** the error message if the pragma fails. ^If the 923 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 924 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 925 ** file control returns [SQLITE_OK], then the parser assumes that the 926 ** VFS has handled the PRAGMA itself and the parser generates a no-op 927 ** prepared statement if result string is NULL, or that returns a copy 928 ** of the result string if the string is non-NULL. 929 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 930 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 931 ** that the VFS encountered an error while handling the [PRAGMA] and the 932 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 933 ** file control occurs at the beginning of pragma statement analysis and so 934 ** it is able to override built-in [PRAGMA] statements. 935 ** 936 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 937 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 938 ** file-control may be invoked by SQLite on the database file handle 939 ** shortly after it is opened in order to provide a custom VFS with access 940 ** to the connections busy-handler callback. The argument is of type (void **) 941 ** - an array of two (void *) values. The first (void *) actually points 942 ** to a function of type (int (*)(void *)). In order to invoke the connections 943 ** busy-handler, this function should be invoked with the second (void *) in 944 ** the array as the only argument. If it returns non-zero, then the operation 945 ** should be retried. If it returns zero, the custom VFS should abandon the 946 ** current operation. 947 ** 948 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 949 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 950 ** to have SQLite generate a 951 ** temporary filename using the same algorithm that is followed to generate 952 ** temporary filenames for TEMP tables and other internal uses. The 953 ** argument should be a char** which will be filled with the filename 954 ** written into memory obtained from [sqlite3_malloc()]. The caller should 955 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 956 ** 957 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 958 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 959 ** maximum number of bytes that will be used for memory-mapped I/O. 960 ** The argument is a pointer to a value of type sqlite3_int64 that 961 ** is an advisory maximum number of bytes in the file to memory map. The 962 ** pointer is overwritten with the old value. The limit is not changed if 963 ** the value originally pointed to is negative, and so the current limit 964 ** can be queried by passing in a pointer to a negative number. This 965 ** file-control is used internally to implement [PRAGMA mmap_size]. 966 ** 967 ** <li>[[SQLITE_FCNTL_TRACE]] 968 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 969 ** to the VFS about what the higher layers of the SQLite stack are doing. 970 ** This file control is used by some VFS activity tracing [shims]. 971 ** The argument is a zero-terminated string. Higher layers in the 972 ** SQLite stack may generate instances of this file control if 973 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 974 ** 975 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 976 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 977 ** pointer to an integer and it writes a boolean into that integer depending 978 ** on whether or not the file has been renamed, moved, or deleted since it 979 ** was first opened. 980 ** 981 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 982 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 983 ** underlying native file handle associated with a file handle. This file 984 ** control interprets its argument as a pointer to a native file handle and 985 ** writes the resulting value there. 986 ** 987 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 988 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 989 ** opcode causes the xFileControl method to swap the file handle with the one 990 ** pointed to by the pArg argument. This capability is used during testing 991 ** and only needs to be supported when SQLITE_TEST is defined. 992 ** 993 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 994 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 995 ** be advantageous to block on the next WAL lock if the lock is not immediately 996 ** available. The WAL subsystem issues this signal during rare 997 ** circumstances in order to fix a problem with priority inversion. 998 ** Applications should <em>not</em> use this file-control. 999 ** 1000 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1001 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1002 ** VFS should return SQLITE_NOTFOUND for this opcode. 1003 ** 1004 ** <li>[[SQLITE_FCNTL_RBU]] 1005 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1006 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1007 ** this opcode. 1008 ** </ul> 1009 */ 1010 #define SQLITE_FCNTL_LOCKSTATE 1 1011 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1012 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1013 #define SQLITE_FCNTL_LAST_ERRNO 4 1014 #define SQLITE_FCNTL_SIZE_HINT 5 1015 #define SQLITE_FCNTL_CHUNK_SIZE 6 1016 #define SQLITE_FCNTL_FILE_POINTER 7 1017 #define SQLITE_FCNTL_SYNC_OMITTED 8 1018 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1019 #define SQLITE_FCNTL_PERSIST_WAL 10 1020 #define SQLITE_FCNTL_OVERWRITE 11 1021 #define SQLITE_FCNTL_VFSNAME 12 1022 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1023 #define SQLITE_FCNTL_PRAGMA 14 1024 #define SQLITE_FCNTL_BUSYHANDLER 15 1025 #define SQLITE_FCNTL_TEMPFILENAME 16 1026 #define SQLITE_FCNTL_MMAP_SIZE 18 1027 #define SQLITE_FCNTL_TRACE 19 1028 #define SQLITE_FCNTL_HAS_MOVED 20 1029 #define SQLITE_FCNTL_SYNC 21 1030 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1031 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1032 #define SQLITE_FCNTL_WAL_BLOCK 24 1033 #define SQLITE_FCNTL_ZIPVFS 25 1034 #define SQLITE_FCNTL_RBU 26 1035 #define SQLITE_FCNTL_VFS_POINTER 27 1036 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1037 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1038 #define SQLITE_FCNTL_PDB 30 1039 1040 /* deprecated names */ 1041 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1042 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1043 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1044 1045 1046 /* 1047 ** CAPI3REF: Mutex Handle 1048 ** 1049 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1050 ** abstract type for a mutex object. The SQLite core never looks 1051 ** at the internal representation of an [sqlite3_mutex]. It only 1052 ** deals with pointers to the [sqlite3_mutex] object. 1053 ** 1054 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1055 */ 1056 typedef struct sqlite3_mutex sqlite3_mutex; 1057 1058 /* 1059 ** CAPI3REF: Loadable Extension Thunk 1060 ** 1061 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1062 ** the third parameter to entry points of [loadable extensions]. This 1063 ** structure must be typedefed in order to work around compiler warnings 1064 ** on some platforms. 1065 */ 1066 typedef struct sqlite3_api_routines sqlite3_api_routines; 1067 1068 /* 1069 ** CAPI3REF: OS Interface Object 1070 ** 1071 ** An instance of the sqlite3_vfs object defines the interface between 1072 ** the SQLite core and the underlying operating system. The "vfs" 1073 ** in the name of the object stands for "virtual file system". See 1074 ** the [VFS | VFS documentation] for further information. 1075 ** 1076 ** The value of the iVersion field is initially 1 but may be larger in 1077 ** future versions of SQLite. Additional fields may be appended to this 1078 ** object when the iVersion value is increased. Note that the structure 1079 ** of the sqlite3_vfs object changes in the transaction between 1080 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1081 ** modified. 1082 ** 1083 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1084 ** structure used by this VFS. mxPathname is the maximum length of 1085 ** a pathname in this VFS. 1086 ** 1087 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1088 ** the pNext pointer. The [sqlite3_vfs_register()] 1089 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1090 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1091 ** searches the list. Neither the application code nor the VFS 1092 ** implementation should use the pNext pointer. 1093 ** 1094 ** The pNext field is the only field in the sqlite3_vfs 1095 ** structure that SQLite will ever modify. SQLite will only access 1096 ** or modify this field while holding a particular static mutex. 1097 ** The application should never modify anything within the sqlite3_vfs 1098 ** object once the object has been registered. 1099 ** 1100 ** The zName field holds the name of the VFS module. The name must 1101 ** be unique across all VFS modules. 1102 ** 1103 ** [[sqlite3_vfs.xOpen]] 1104 ** ^SQLite guarantees that the zFilename parameter to xOpen 1105 ** is either a NULL pointer or string obtained 1106 ** from xFullPathname() with an optional suffix added. 1107 ** ^If a suffix is added to the zFilename parameter, it will 1108 ** consist of a single "-" character followed by no more than 1109 ** 11 alphanumeric and/or "-" characters. 1110 ** ^SQLite further guarantees that 1111 ** the string will be valid and unchanged until xClose() is 1112 ** called. Because of the previous sentence, 1113 ** the [sqlite3_file] can safely store a pointer to the 1114 ** filename if it needs to remember the filename for some reason. 1115 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1116 ** must invent its own temporary name for the file. ^Whenever the 1117 ** xFilename parameter is NULL it will also be the case that the 1118 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1119 ** 1120 ** The flags argument to xOpen() includes all bits set in 1121 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1122 ** or [sqlite3_open16()] is used, then flags includes at least 1123 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1124 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1125 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1126 ** 1127 ** ^(SQLite will also add one of the following flags to the xOpen() 1128 ** call, depending on the object being opened: 1129 ** 1130 ** <ul> 1131 ** <li> [SQLITE_OPEN_MAIN_DB] 1132 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1133 ** <li> [SQLITE_OPEN_TEMP_DB] 1134 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1135 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1136 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1137 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1138 ** <li> [SQLITE_OPEN_WAL] 1139 ** </ul>)^ 1140 ** 1141 ** The file I/O implementation can use the object type flags to 1142 ** change the way it deals with files. For example, an application 1143 ** that does not care about crash recovery or rollback might make 1144 ** the open of a journal file a no-op. Writes to this journal would 1145 ** also be no-ops, and any attempt to read the journal would return 1146 ** SQLITE_IOERR. Or the implementation might recognize that a database 1147 ** file will be doing page-aligned sector reads and writes in a random 1148 ** order and set up its I/O subsystem accordingly. 1149 ** 1150 ** SQLite might also add one of the following flags to the xOpen method: 1151 ** 1152 ** <ul> 1153 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1154 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1155 ** </ul> 1156 ** 1157 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1158 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1159 ** will be set for TEMP databases and their journals, transient 1160 ** databases, and subjournals. 1161 ** 1162 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1163 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1164 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1165 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1166 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1167 ** be created, and that it is an error if it already exists. 1168 ** It is <i>not</i> used to indicate the file should be opened 1169 ** for exclusive access. 1170 ** 1171 ** ^At least szOsFile bytes of memory are allocated by SQLite 1172 ** to hold the [sqlite3_file] structure passed as the third 1173 ** argument to xOpen. The xOpen method does not have to 1174 ** allocate the structure; it should just fill it in. Note that 1175 ** the xOpen method must set the sqlite3_file.pMethods to either 1176 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1177 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1178 ** element will be valid after xOpen returns regardless of the success 1179 ** or failure of the xOpen call. 1180 ** 1181 ** [[sqlite3_vfs.xAccess]] 1182 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1183 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1184 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1185 ** to test whether a file is at least readable. The file can be a 1186 ** directory. 1187 ** 1188 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1189 ** output buffer xFullPathname. The exact size of the output buffer 1190 ** is also passed as a parameter to both methods. If the output buffer 1191 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1192 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1193 ** to prevent this by setting mxPathname to a sufficiently large value. 1194 ** 1195 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1196 ** interfaces are not strictly a part of the filesystem, but they are 1197 ** included in the VFS structure for completeness. 1198 ** The xRandomness() function attempts to return nBytes bytes 1199 ** of good-quality randomness into zOut. The return value is 1200 ** the actual number of bytes of randomness obtained. 1201 ** The xSleep() method causes the calling thread to sleep for at 1202 ** least the number of microseconds given. ^The xCurrentTime() 1203 ** method returns a Julian Day Number for the current date and time as 1204 ** a floating point value. 1205 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1206 ** Day Number multiplied by 86400000 (the number of milliseconds in 1207 ** a 24-hour day). 1208 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1209 ** date and time if that method is available (if iVersion is 2 or 1210 ** greater and the function pointer is not NULL) and will fall back 1211 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1212 ** 1213 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1214 ** are not used by the SQLite core. These optional interfaces are provided 1215 ** by some VFSes to facilitate testing of the VFS code. By overriding 1216 ** system calls with functions under its control, a test program can 1217 ** simulate faults and error conditions that would otherwise be difficult 1218 ** or impossible to induce. The set of system calls that can be overridden 1219 ** varies from one VFS to another, and from one version of the same VFS to the 1220 ** next. Applications that use these interfaces must be prepared for any 1221 ** or all of these interfaces to be NULL or for their behavior to change 1222 ** from one release to the next. Applications must not attempt to access 1223 ** any of these methods if the iVersion of the VFS is less than 3. 1224 */ 1225 typedef struct sqlite3_vfs sqlite3_vfs; 1226 typedef void (*sqlite3_syscall_ptr)(void); 1227 struct sqlite3_vfs { 1228 int iVersion; /* Structure version number (currently 3) */ 1229 int szOsFile; /* Size of subclassed sqlite3_file */ 1230 int mxPathname; /* Maximum file pathname length */ 1231 sqlite3_vfs *pNext; /* Next registered VFS */ 1232 const char *zName; /* Name of this virtual file system */ 1233 void *pAppData; /* Pointer to application-specific data */ 1234 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1235 int flags, int *pOutFlags); 1236 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1237 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1238 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1239 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1240 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1241 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1242 void (*xDlClose)(sqlite3_vfs*, void*); 1243 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1244 int (*xSleep)(sqlite3_vfs*, int microseconds); 1245 int (*xCurrentTime)(sqlite3_vfs*, double*); 1246 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1247 /* 1248 ** The methods above are in version 1 of the sqlite_vfs object 1249 ** definition. Those that follow are added in version 2 or later 1250 */ 1251 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1252 /* 1253 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1254 ** Those below are for version 3 and greater. 1255 */ 1256 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1257 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1258 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1259 /* 1260 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1261 ** New fields may be appended in future versions. The iVersion 1262 ** value will increment whenever this happens. 1263 */ 1264 }; 1265 1266 /* 1267 ** CAPI3REF: Flags for the xAccess VFS method 1268 ** 1269 ** These integer constants can be used as the third parameter to 1270 ** the xAccess method of an [sqlite3_vfs] object. They determine 1271 ** what kind of permissions the xAccess method is looking for. 1272 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1273 ** simply checks whether the file exists. 1274 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1275 ** checks whether the named directory is both readable and writable 1276 ** (in other words, if files can be added, removed, and renamed within 1277 ** the directory). 1278 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1279 ** [temp_store_directory pragma], though this could change in a future 1280 ** release of SQLite. 1281 ** With SQLITE_ACCESS_READ, the xAccess method 1282 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1283 ** currently unused, though it might be used in a future release of 1284 ** SQLite. 1285 */ 1286 #define SQLITE_ACCESS_EXISTS 0 1287 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1288 #define SQLITE_ACCESS_READ 2 /* Unused */ 1289 1290 /* 1291 ** CAPI3REF: Flags for the xShmLock VFS method 1292 ** 1293 ** These integer constants define the various locking operations 1294 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1295 ** following are the only legal combinations of flags to the 1296 ** xShmLock method: 1297 ** 1298 ** <ul> 1299 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1300 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1301 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1302 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1303 ** </ul> 1304 ** 1305 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1306 ** was given on the corresponding lock. 1307 ** 1308 ** The xShmLock method can transition between unlocked and SHARED or 1309 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1310 ** and EXCLUSIVE. 1311 */ 1312 #define SQLITE_SHM_UNLOCK 1 1313 #define SQLITE_SHM_LOCK 2 1314 #define SQLITE_SHM_SHARED 4 1315 #define SQLITE_SHM_EXCLUSIVE 8 1316 1317 /* 1318 ** CAPI3REF: Maximum xShmLock index 1319 ** 1320 ** The xShmLock method on [sqlite3_io_methods] may use values 1321 ** between 0 and this upper bound as its "offset" argument. 1322 ** The SQLite core will never attempt to acquire or release a 1323 ** lock outside of this range 1324 */ 1325 #define SQLITE_SHM_NLOCK 8 1326 1327 1328 /* 1329 ** CAPI3REF: Initialize The SQLite Library 1330 ** 1331 ** ^The sqlite3_initialize() routine initializes the 1332 ** SQLite library. ^The sqlite3_shutdown() routine 1333 ** deallocates any resources that were allocated by sqlite3_initialize(). 1334 ** These routines are designed to aid in process initialization and 1335 ** shutdown on embedded systems. Workstation applications using 1336 ** SQLite normally do not need to invoke either of these routines. 1337 ** 1338 ** A call to sqlite3_initialize() is an "effective" call if it is 1339 ** the first time sqlite3_initialize() is invoked during the lifetime of 1340 ** the process, or if it is the first time sqlite3_initialize() is invoked 1341 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1342 ** of sqlite3_initialize() does any initialization. All other calls 1343 ** are harmless no-ops.)^ 1344 ** 1345 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1346 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1347 ** an effective call to sqlite3_shutdown() does any deinitialization. 1348 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1349 ** 1350 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1351 ** is not. The sqlite3_shutdown() interface must only be called from a 1352 ** single thread. All open [database connections] must be closed and all 1353 ** other SQLite resources must be deallocated prior to invoking 1354 ** sqlite3_shutdown(). 1355 ** 1356 ** Among other things, ^sqlite3_initialize() will invoke 1357 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1358 ** will invoke sqlite3_os_end(). 1359 ** 1360 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1361 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1362 ** the library (perhaps it is unable to allocate a needed resource such 1363 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1364 ** 1365 ** ^The sqlite3_initialize() routine is called internally by many other 1366 ** SQLite interfaces so that an application usually does not need to 1367 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1368 ** calls sqlite3_initialize() so the SQLite library will be automatically 1369 ** initialized when [sqlite3_open()] is called if it has not be initialized 1370 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1371 ** compile-time option, then the automatic calls to sqlite3_initialize() 1372 ** are omitted and the application must call sqlite3_initialize() directly 1373 ** prior to using any other SQLite interface. For maximum portability, 1374 ** it is recommended that applications always invoke sqlite3_initialize() 1375 ** directly prior to using any other SQLite interface. Future releases 1376 ** of SQLite may require this. In other words, the behavior exhibited 1377 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1378 ** default behavior in some future release of SQLite. 1379 ** 1380 ** The sqlite3_os_init() routine does operating-system specific 1381 ** initialization of the SQLite library. The sqlite3_os_end() 1382 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1383 ** performed by these routines include allocation or deallocation 1384 ** of static resources, initialization of global variables, 1385 ** setting up a default [sqlite3_vfs] module, or setting up 1386 ** a default configuration using [sqlite3_config()]. 1387 ** 1388 ** The application should never invoke either sqlite3_os_init() 1389 ** or sqlite3_os_end() directly. The application should only invoke 1390 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1391 ** interface is called automatically by sqlite3_initialize() and 1392 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1393 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1394 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1395 ** When [custom builds | built for other platforms] 1396 ** (using the [SQLITE_OS_OTHER=1] compile-time 1397 ** option) the application must supply a suitable implementation for 1398 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1399 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1400 ** must return [SQLITE_OK] on success and some other [error code] upon 1401 ** failure. 1402 */ 1403 SQLITE_API int sqlite3_initialize(void); 1404 SQLITE_API int sqlite3_shutdown(void); 1405 SQLITE_API int sqlite3_os_init(void); 1406 SQLITE_API int sqlite3_os_end(void); 1407 1408 /* 1409 ** CAPI3REF: Configuring The SQLite Library 1410 ** 1411 ** The sqlite3_config() interface is used to make global configuration 1412 ** changes to SQLite in order to tune SQLite to the specific needs of 1413 ** the application. The default configuration is recommended for most 1414 ** applications and so this routine is usually not necessary. It is 1415 ** provided to support rare applications with unusual needs. 1416 ** 1417 ** <b>The sqlite3_config() interface is not threadsafe. The application 1418 ** must ensure that no other SQLite interfaces are invoked by other 1419 ** threads while sqlite3_config() is running.</b> 1420 ** 1421 ** The sqlite3_config() interface 1422 ** may only be invoked prior to library initialization using 1423 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1424 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1425 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1426 ** Note, however, that ^sqlite3_config() can be called as part of the 1427 ** implementation of an application-defined [sqlite3_os_init()]. 1428 ** 1429 ** The first argument to sqlite3_config() is an integer 1430 ** [configuration option] that determines 1431 ** what property of SQLite is to be configured. Subsequent arguments 1432 ** vary depending on the [configuration option] 1433 ** in the first argument. 1434 ** 1435 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1436 ** ^If the option is unknown or SQLite is unable to set the option 1437 ** then this routine returns a non-zero [error code]. 1438 */ 1439 SQLITE_API int sqlite3_config(int, ...); 1440 1441 /* 1442 ** CAPI3REF: Configure database connections 1443 ** METHOD: sqlite3 1444 ** 1445 ** The sqlite3_db_config() interface is used to make configuration 1446 ** changes to a [database connection]. The interface is similar to 1447 ** [sqlite3_config()] except that the changes apply to a single 1448 ** [database connection] (specified in the first argument). 1449 ** 1450 ** The second argument to sqlite3_db_config(D,V,...) is the 1451 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1452 ** that indicates what aspect of the [database connection] is being configured. 1453 ** Subsequent arguments vary depending on the configuration verb. 1454 ** 1455 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1456 ** the call is considered successful. 1457 */ 1458 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1459 1460 /* 1461 ** CAPI3REF: Memory Allocation Routines 1462 ** 1463 ** An instance of this object defines the interface between SQLite 1464 ** and low-level memory allocation routines. 1465 ** 1466 ** This object is used in only one place in the SQLite interface. 1467 ** A pointer to an instance of this object is the argument to 1468 ** [sqlite3_config()] when the configuration option is 1469 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1470 ** By creating an instance of this object 1471 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1472 ** during configuration, an application can specify an alternative 1473 ** memory allocation subsystem for SQLite to use for all of its 1474 ** dynamic memory needs. 1475 ** 1476 ** Note that SQLite comes with several [built-in memory allocators] 1477 ** that are perfectly adequate for the overwhelming majority of applications 1478 ** and that this object is only useful to a tiny minority of applications 1479 ** with specialized memory allocation requirements. This object is 1480 ** also used during testing of SQLite in order to specify an alternative 1481 ** memory allocator that simulates memory out-of-memory conditions in 1482 ** order to verify that SQLite recovers gracefully from such 1483 ** conditions. 1484 ** 1485 ** The xMalloc, xRealloc, and xFree methods must work like the 1486 ** malloc(), realloc() and free() functions from the standard C library. 1487 ** ^SQLite guarantees that the second argument to 1488 ** xRealloc is always a value returned by a prior call to xRoundup. 1489 ** 1490 ** xSize should return the allocated size of a memory allocation 1491 ** previously obtained from xMalloc or xRealloc. The allocated size 1492 ** is always at least as big as the requested size but may be larger. 1493 ** 1494 ** The xRoundup method returns what would be the allocated size of 1495 ** a memory allocation given a particular requested size. Most memory 1496 ** allocators round up memory allocations at least to the next multiple 1497 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1498 ** Every memory allocation request coming in through [sqlite3_malloc()] 1499 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1500 ** that causes the corresponding memory allocation to fail. 1501 ** 1502 ** The xInit method initializes the memory allocator. For example, 1503 ** it might allocate any require mutexes or initialize internal data 1504 ** structures. The xShutdown method is invoked (indirectly) by 1505 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1506 ** by xInit. The pAppData pointer is used as the only parameter to 1507 ** xInit and xShutdown. 1508 ** 1509 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1510 ** the xInit method, so the xInit method need not be threadsafe. The 1511 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1512 ** not need to be threadsafe either. For all other methods, SQLite 1513 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1514 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1515 ** it is by default) and so the methods are automatically serialized. 1516 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1517 ** methods must be threadsafe or else make their own arrangements for 1518 ** serialization. 1519 ** 1520 ** SQLite will never invoke xInit() more than once without an intervening 1521 ** call to xShutdown(). 1522 */ 1523 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1524 struct sqlite3_mem_methods { 1525 void *(*xMalloc)(int); /* Memory allocation function */ 1526 void (*xFree)(void*); /* Free a prior allocation */ 1527 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1528 int (*xSize)(void*); /* Return the size of an allocation */ 1529 int (*xRoundup)(int); /* Round up request size to allocation size */ 1530 int (*xInit)(void*); /* Initialize the memory allocator */ 1531 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1532 void *pAppData; /* Argument to xInit() and xShutdown() */ 1533 }; 1534 1535 /* 1536 ** CAPI3REF: Configuration Options 1537 ** KEYWORDS: {configuration option} 1538 ** 1539 ** These constants are the available integer configuration options that 1540 ** can be passed as the first argument to the [sqlite3_config()] interface. 1541 ** 1542 ** New configuration options may be added in future releases of SQLite. 1543 ** Existing configuration options might be discontinued. Applications 1544 ** should check the return code from [sqlite3_config()] to make sure that 1545 ** the call worked. The [sqlite3_config()] interface will return a 1546 ** non-zero [error code] if a discontinued or unsupported configuration option 1547 ** is invoked. 1548 ** 1549 ** <dl> 1550 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1551 ** <dd>There are no arguments to this option. ^This option sets the 1552 ** [threading mode] to Single-thread. In other words, it disables 1553 ** all mutexing and puts SQLite into a mode where it can only be used 1554 ** by a single thread. ^If SQLite is compiled with 1555 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1556 ** it is not possible to change the [threading mode] from its default 1557 ** value of Single-thread and so [sqlite3_config()] will return 1558 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1559 ** configuration option.</dd> 1560 ** 1561 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1562 ** <dd>There are no arguments to this option. ^This option sets the 1563 ** [threading mode] to Multi-thread. In other words, it disables 1564 ** mutexing on [database connection] and [prepared statement] objects. 1565 ** The application is responsible for serializing access to 1566 ** [database connections] and [prepared statements]. But other mutexes 1567 ** are enabled so that SQLite will be safe to use in a multi-threaded 1568 ** environment as long as no two threads attempt to use the same 1569 ** [database connection] at the same time. ^If SQLite is compiled with 1570 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1571 ** it is not possible to set the Multi-thread [threading mode] and 1572 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1573 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1574 ** 1575 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1576 ** <dd>There are no arguments to this option. ^This option sets the 1577 ** [threading mode] to Serialized. In other words, this option enables 1578 ** all mutexes including the recursive 1579 ** mutexes on [database connection] and [prepared statement] objects. 1580 ** In this mode (which is the default when SQLite is compiled with 1581 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1582 ** to [database connections] and [prepared statements] so that the 1583 ** application is free to use the same [database connection] or the 1584 ** same [prepared statement] in different threads at the same time. 1585 ** ^If SQLite is compiled with 1586 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1587 ** it is not possible to set the Serialized [threading mode] and 1588 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1589 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1590 ** 1591 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1592 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1593 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1594 ** The argument specifies 1595 ** alternative low-level memory allocation routines to be used in place of 1596 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1597 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1598 ** before the [sqlite3_config()] call returns.</dd> 1599 ** 1600 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1601 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1602 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1603 ** The [sqlite3_mem_methods] 1604 ** structure is filled with the currently defined memory allocation routines.)^ 1605 ** This option can be used to overload the default memory allocation 1606 ** routines with a wrapper that simulations memory allocation failure or 1607 ** tracks memory usage, for example. </dd> 1608 ** 1609 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1610 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1611 ** interpreted as a boolean, which enables or disables the collection of 1612 ** memory allocation statistics. ^(When memory allocation statistics are 1613 ** disabled, the following SQLite interfaces become non-operational: 1614 ** <ul> 1615 ** <li> [sqlite3_memory_used()] 1616 ** <li> [sqlite3_memory_highwater()] 1617 ** <li> [sqlite3_soft_heap_limit64()] 1618 ** <li> [sqlite3_status64()] 1619 ** </ul>)^ 1620 ** ^Memory allocation statistics are enabled by default unless SQLite is 1621 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1622 ** allocation statistics are disabled by default. 1623 ** </dd> 1624 ** 1625 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1626 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1627 ** that SQLite can use for scratch memory. ^(There are three arguments 1628 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1629 ** aligned memory buffer from which the scratch allocations will be 1630 ** drawn, the size of each scratch allocation (sz), 1631 ** and the maximum number of scratch allocations (N).)^ 1632 ** The first argument must be a pointer to an 8-byte aligned buffer 1633 ** of at least sz*N bytes of memory. 1634 ** ^SQLite will not use more than one scratch buffers per thread. 1635 ** ^SQLite will never request a scratch buffer that is more than 6 1636 ** times the database page size. 1637 ** ^If SQLite needs needs additional 1638 ** scratch memory beyond what is provided by this configuration option, then 1639 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1640 ** ^When the application provides any amount of scratch memory using 1641 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1642 ** [sqlite3_malloc|heap allocations]. 1643 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1644 ** fragmentation in low-memory embedded systems. 1645 ** </dd> 1646 ** 1647 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1648 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1649 ** that SQLite can use for the database page cache with the default page 1650 ** cache implementation. 1651 ** This configuration option is a no-op if an application-define page 1652 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1653 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1654 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1655 ** and the number of cache lines (N). 1656 ** The sz argument should be the size of the largest database page 1657 ** (a power of two between 512 and 65536) plus some extra bytes for each 1658 ** page header. ^The number of extra bytes needed by the page header 1659 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1660 ** ^It is harmless, apart from the wasted memory, 1661 ** for the sz parameter to be larger than necessary. The pMem 1662 ** argument must be either a NULL pointer or a pointer to an 8-byte 1663 ** aligned block of memory of at least sz*N bytes, otherwise 1664 ** subsequent behavior is undefined. 1665 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1666 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1667 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1668 ** is exhausted. 1669 ** ^If pMem is NULL and N is non-zero, then each database connection 1670 ** does an initial bulk allocation for page cache memory 1671 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1672 ** of -1024*N bytes if N is negative, . ^If additional 1673 ** page cache memory is needed beyond what is provided by the initial 1674 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1675 ** additional cache line. </dd> 1676 ** 1677 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1678 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1679 ** that SQLite will use for all of its dynamic memory allocation needs 1680 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1681 ** [SQLITE_CONFIG_PAGECACHE]. 1682 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1683 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1684 ** [SQLITE_ERROR] if invoked otherwise. 1685 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1686 ** An 8-byte aligned pointer to the memory, 1687 ** the number of bytes in the memory buffer, and the minimum allocation size. 1688 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1689 ** to using its default memory allocator (the system malloc() implementation), 1690 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1691 ** memory pointer is not NULL then the alternative memory 1692 ** allocator is engaged to handle all of SQLites memory allocation needs. 1693 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1694 ** boundary or subsequent behavior of SQLite will be undefined. 1695 ** The minimum allocation size is capped at 2**12. Reasonable values 1696 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1697 ** 1698 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1699 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1700 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1701 ** The argument specifies alternative low-level mutex routines to be used 1702 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1703 ** the content of the [sqlite3_mutex_methods] structure before the call to 1704 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1705 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1706 ** the entire mutexing subsystem is omitted from the build and hence calls to 1707 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1708 ** return [SQLITE_ERROR].</dd> 1709 ** 1710 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1711 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1712 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1713 ** [sqlite3_mutex_methods] 1714 ** structure is filled with the currently defined mutex routines.)^ 1715 ** This option can be used to overload the default mutex allocation 1716 ** routines with a wrapper used to track mutex usage for performance 1717 ** profiling or testing, for example. ^If SQLite is compiled with 1718 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1719 ** the entire mutexing subsystem is omitted from the build and hence calls to 1720 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1721 ** return [SQLITE_ERROR].</dd> 1722 ** 1723 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1724 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1725 ** the default size of lookaside memory on each [database connection]. 1726 ** The first argument is the 1727 ** size of each lookaside buffer slot and the second is the number of 1728 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1729 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1730 ** option to [sqlite3_db_config()] can be used to change the lookaside 1731 ** configuration on individual connections.)^ </dd> 1732 ** 1733 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1734 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1735 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1736 ** the interface to a custom page cache implementation.)^ 1737 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1738 ** 1739 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1740 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1741 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1742 ** the current page cache implementation into that object.)^ </dd> 1743 ** 1744 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1745 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1746 ** global [error log]. 1747 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1748 ** function with a call signature of void(*)(void*,int,const char*), 1749 ** and a pointer to void. ^If the function pointer is not NULL, it is 1750 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1751 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1752 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1753 ** passed through as the first parameter to the application-defined logger 1754 ** function whenever that function is invoked. ^The second parameter to 1755 ** the logger function is a copy of the first parameter to the corresponding 1756 ** [sqlite3_log()] call and is intended to be a [result code] or an 1757 ** [extended result code]. ^The third parameter passed to the logger is 1758 ** log message after formatting via [sqlite3_snprintf()]. 1759 ** The SQLite logging interface is not reentrant; the logger function 1760 ** supplied by the application must not invoke any SQLite interface. 1761 ** In a multi-threaded application, the application-defined logger 1762 ** function must be threadsafe. </dd> 1763 ** 1764 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1765 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1766 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1767 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1768 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1769 ** [sqlite3_open16()] or 1770 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1771 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1772 ** connection is opened. ^If it is globally disabled, filenames are 1773 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1774 ** database connection is opened. ^(By default, URI handling is globally 1775 ** disabled. The default value may be changed by compiling with the 1776 ** [SQLITE_USE_URI] symbol defined.)^ 1777 ** 1778 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1779 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1780 ** argument which is interpreted as a boolean in order to enable or disable 1781 ** the use of covering indices for full table scans in the query optimizer. 1782 ** ^The default setting is determined 1783 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1784 ** if that compile-time option is omitted. 1785 ** The ability to disable the use of covering indices for full table scans 1786 ** is because some incorrectly coded legacy applications might malfunction 1787 ** when the optimization is enabled. Providing the ability to 1788 ** disable the optimization allows the older, buggy application code to work 1789 ** without change even with newer versions of SQLite. 1790 ** 1791 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1792 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1793 ** <dd> These options are obsolete and should not be used by new code. 1794 ** They are retained for backwards compatibility but are now no-ops. 1795 ** </dd> 1796 ** 1797 ** [[SQLITE_CONFIG_SQLLOG]] 1798 ** <dt>SQLITE_CONFIG_SQLLOG 1799 ** <dd>This option is only available if sqlite is compiled with the 1800 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1801 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1802 ** The second should be of type (void*). The callback is invoked by the library 1803 ** in three separate circumstances, identified by the value passed as the 1804 ** fourth parameter. If the fourth parameter is 0, then the database connection 1805 ** passed as the second argument has just been opened. The third argument 1806 ** points to a buffer containing the name of the main database file. If the 1807 ** fourth parameter is 1, then the SQL statement that the third parameter 1808 ** points to has just been executed. Or, if the fourth parameter is 2, then 1809 ** the connection being passed as the second parameter is being closed. The 1810 ** third parameter is passed NULL In this case. An example of using this 1811 ** configuration option can be seen in the "test_sqllog.c" source file in 1812 ** the canonical SQLite source tree.</dd> 1813 ** 1814 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1815 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1816 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1817 ** that are the default mmap size limit (the default setting for 1818 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1819 ** ^The default setting can be overridden by each database connection using 1820 ** either the [PRAGMA mmap_size] command, or by using the 1821 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1822 ** will be silently truncated if necessary so that it does not exceed the 1823 ** compile-time maximum mmap size set by the 1824 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1825 ** ^If either argument to this option is negative, then that argument is 1826 ** changed to its compile-time default. 1827 ** 1828 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1829 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1830 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1831 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1832 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1833 ** that specifies the maximum size of the created heap. 1834 ** 1835 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1836 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1837 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1838 ** is a pointer to an integer and writes into that integer the number of extra 1839 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1840 ** The amount of extra space required can change depending on the compiler, 1841 ** target platform, and SQLite version. 1842 ** 1843 ** [[SQLITE_CONFIG_PMASZ]] 1844 ** <dt>SQLITE_CONFIG_PMASZ 1845 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1846 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1847 ** sorter to that integer. The default minimum PMA Size is set by the 1848 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1849 ** to help with sort operations when multithreaded sorting 1850 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1851 ** to be sorted exceeds the page size times the minimum of the 1852 ** [PRAGMA cache_size] setting and this value. 1853 ** 1854 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1855 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1856 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1857 ** becomes the [statement journal] spill-to-disk threshold. 1858 ** [Statement journals] are held in memory until their size (in bytes) 1859 ** exceeds this threshold, at which point they are written to disk. 1860 ** Or if the threshold is -1, statement journals are always held 1861 ** exclusively in memory. 1862 ** Since many statement journals never become large, setting the spill 1863 ** threshold to a value such as 64KiB can greatly reduce the amount of 1864 ** I/O required to support statement rollback. 1865 ** The default value for this setting is controlled by the 1866 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1867 ** </dl> 1868 */ 1869 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1870 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1871 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1872 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1873 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1874 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1875 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1876 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1877 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1878 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1879 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1880 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1881 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1882 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1883 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1884 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1885 #define SQLITE_CONFIG_URI 17 /* int */ 1886 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1887 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1888 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1889 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1890 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1891 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1892 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1893 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1894 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1895 1896 /* 1897 ** CAPI3REF: Database Connection Configuration Options 1898 ** 1899 ** These constants are the available integer configuration options that 1900 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1901 ** 1902 ** New configuration options may be added in future releases of SQLite. 1903 ** Existing configuration options might be discontinued. Applications 1904 ** should check the return code from [sqlite3_db_config()] to make sure that 1905 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1906 ** non-zero [error code] if a discontinued or unsupported configuration option 1907 ** is invoked. 1908 ** 1909 ** <dl> 1910 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1911 ** <dd> ^This option takes three additional arguments that determine the 1912 ** [lookaside memory allocator] configuration for the [database connection]. 1913 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1914 ** pointer to a memory buffer to use for lookaside memory. 1915 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1916 ** may be NULL in which case SQLite will allocate the 1917 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1918 ** size of each lookaside buffer slot. ^The third argument is the number of 1919 ** slots. The size of the buffer in the first argument must be greater than 1920 ** or equal to the product of the second and third arguments. The buffer 1921 ** must be aligned to an 8-byte boundary. ^If the second argument to 1922 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1923 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1924 ** configuration for a database connection can only be changed when that 1925 ** connection is not currently using lookaside memory, or in other words 1926 ** when the "current value" returned by 1927 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1928 ** Any attempt to change the lookaside memory configuration when lookaside 1929 ** memory is in use leaves the configuration unchanged and returns 1930 ** [SQLITE_BUSY].)^</dd> 1931 ** 1932 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1933 ** <dd> ^This option is used to enable or disable the enforcement of 1934 ** [foreign key constraints]. There should be two additional arguments. 1935 ** The first argument is an integer which is 0 to disable FK enforcement, 1936 ** positive to enable FK enforcement or negative to leave FK enforcement 1937 ** unchanged. The second parameter is a pointer to an integer into which 1938 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1939 ** following this call. The second parameter may be a NULL pointer, in 1940 ** which case the FK enforcement setting is not reported back. </dd> 1941 ** 1942 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1943 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1944 ** There should be two additional arguments. 1945 ** The first argument is an integer which is 0 to disable triggers, 1946 ** positive to enable triggers or negative to leave the setting unchanged. 1947 ** The second parameter is a pointer to an integer into which 1948 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1949 ** following this call. The second parameter may be a NULL pointer, in 1950 ** which case the trigger setting is not reported back. </dd> 1951 ** 1952 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1953 ** <dd> ^This option is used to enable or disable the two-argument 1954 ** version of the [fts3_tokenizer()] function which is part of the 1955 ** [FTS3] full-text search engine extension. 1956 ** There should be two additional arguments. 1957 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1958 ** positive to enable fts3_tokenizer() or negative to leave the setting 1959 ** unchanged. 1960 ** The second parameter is a pointer to an integer into which 1961 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1962 ** following this call. The second parameter may be a NULL pointer, in 1963 ** which case the new setting is not reported back. </dd> 1964 ** 1965 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1966 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1967 ** interface independently of the [load_extension()] SQL function. 1968 ** The [sqlite3_enable_load_extension()] API enables or disables both the 1969 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1970 ** There should be two additional arguments. 1971 ** When the first argument to this interface is 1, then only the C-API is 1972 ** enabled and the SQL function remains disabled. If the first argument to 1973 ** this interface is 0, then both the C-API and the SQL function are disabled. 1974 ** If the first argument is -1, then no changes are made to state of either the 1975 ** C-API or the SQL function. 1976 ** The second parameter is a pointer to an integer into which 1977 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1978 ** is disabled or enabled following this call. The second parameter may 1979 ** be a NULL pointer, in which case the new setting is not reported back. 1980 ** </dd> 1981 ** 1982 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 1983 ** <dd> ^This option is used to change the name of the "main" database 1984 ** schema. ^The sole argument is a pointer to a constant UTF8 string 1985 ** which will become the new schema name in place of "main". ^SQLite 1986 ** does not make a copy of the new main schema name string, so the application 1987 ** must ensure that the argument passed into this DBCONFIG option is unchanged 1988 ** until after the database connection closes. 1989 ** </dd> 1990 ** 1991 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 1992 ** <dd> Usually, when a database in wal mode is closed or detached from a 1993 ** database handle, SQLite checks if this will mean that there are now no 1994 ** connections at all to the database. If so, it performs a checkpoint 1995 ** operation before closing the connection. This option may be used to 1996 ** override this behaviour. The first parameter passed to this operation 1997 ** is an integer - non-zero to disable checkpoints-on-close, or zero (the 1998 ** default) to enable them. The second parameter is a pointer to an integer 1999 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2000 ** have been disabled - 0 if they are not disabled, 1 if they are. 2001 ** </dd> 2002 ** 2003 ** </dl> 2004 */ 2005 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2006 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2007 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2008 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2009 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2010 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2011 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2012 2013 2014 /* 2015 ** CAPI3REF: Enable Or Disable Extended Result Codes 2016 ** METHOD: sqlite3 2017 ** 2018 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2019 ** [extended result codes] feature of SQLite. ^The extended result 2020 ** codes are disabled by default for historical compatibility. 2021 */ 2022 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2023 2024 /* 2025 ** CAPI3REF: Last Insert Rowid 2026 ** METHOD: sqlite3 2027 ** 2028 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2029 ** has a unique 64-bit signed 2030 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2031 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2032 ** names are not also used by explicitly declared columns. ^If 2033 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2034 ** is another alias for the rowid. 2035 ** 2036 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 2037 ** most recent successful [INSERT] into a rowid table or [virtual table] 2038 ** on database connection D. 2039 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 2040 ** ^If no successful [INSERT]s into rowid tables 2041 ** have ever occurred on the database connection D, 2042 ** then sqlite3_last_insert_rowid(D) returns zero. 2043 ** 2044 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 2045 ** method, then this routine will return the [rowid] of the inserted 2046 ** row as long as the trigger or virtual table method is running. 2047 ** But once the trigger or virtual table method ends, the value returned 2048 ** by this routine reverts to what it was before the trigger or virtual 2049 ** table method began.)^ 2050 ** 2051 ** ^An [INSERT] that fails due to a constraint violation is not a 2052 ** successful [INSERT] and does not change the value returned by this 2053 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2054 ** and INSERT OR ABORT make no changes to the return value of this 2055 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2056 ** encounters a constraint violation, it does not fail. The 2057 ** INSERT continues to completion after deleting rows that caused 2058 ** the constraint problem so INSERT OR REPLACE will always change 2059 ** the return value of this interface.)^ 2060 ** 2061 ** ^For the purposes of this routine, an [INSERT] is considered to 2062 ** be successful even if it is subsequently rolled back. 2063 ** 2064 ** This function is accessible to SQL statements via the 2065 ** [last_insert_rowid() SQL function]. 2066 ** 2067 ** If a separate thread performs a new [INSERT] on the same 2068 ** database connection while the [sqlite3_last_insert_rowid()] 2069 ** function is running and thus changes the last insert [rowid], 2070 ** then the value returned by [sqlite3_last_insert_rowid()] is 2071 ** unpredictable and might not equal either the old or the new 2072 ** last insert [rowid]. 2073 */ 2074 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2075 2076 /* 2077 ** CAPI3REF: Count The Number Of Rows Modified 2078 ** METHOD: sqlite3 2079 ** 2080 ** ^This function returns the number of rows modified, inserted or 2081 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2082 ** statement on the database connection specified by the only parameter. 2083 ** ^Executing any other type of SQL statement does not modify the value 2084 ** returned by this function. 2085 ** 2086 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2087 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2088 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2089 ** 2090 ** Changes to a view that are intercepted by 2091 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2092 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2093 ** DELETE statement run on a view is always zero. Only changes made to real 2094 ** tables are counted. 2095 ** 2096 ** Things are more complicated if the sqlite3_changes() function is 2097 ** executed while a trigger program is running. This may happen if the 2098 ** program uses the [changes() SQL function], or if some other callback 2099 ** function invokes sqlite3_changes() directly. Essentially: 2100 ** 2101 ** <ul> 2102 ** <li> ^(Before entering a trigger program the value returned by 2103 ** sqlite3_changes() function is saved. After the trigger program 2104 ** has finished, the original value is restored.)^ 2105 ** 2106 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2107 ** statement sets the value returned by sqlite3_changes() 2108 ** upon completion as normal. Of course, this value will not include 2109 ** any changes performed by sub-triggers, as the sqlite3_changes() 2110 ** value will be saved and restored after each sub-trigger has run.)^ 2111 ** </ul> 2112 ** 2113 ** ^This means that if the changes() SQL function (or similar) is used 2114 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2115 ** returns the value as set when the calling statement began executing. 2116 ** ^If it is used by the second or subsequent such statement within a trigger 2117 ** program, the value returned reflects the number of rows modified by the 2118 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2119 ** 2120 ** See also the [sqlite3_total_changes()] interface, the 2121 ** [count_changes pragma], and the [changes() SQL function]. 2122 ** 2123 ** If a separate thread makes changes on the same database connection 2124 ** while [sqlite3_changes()] is running then the value returned 2125 ** is unpredictable and not meaningful. 2126 */ 2127 SQLITE_API int sqlite3_changes(sqlite3*); 2128 2129 /* 2130 ** CAPI3REF: Total Number Of Rows Modified 2131 ** METHOD: sqlite3 2132 ** 2133 ** ^This function returns the total number of rows inserted, modified or 2134 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2135 ** since the database connection was opened, including those executed as 2136 ** part of trigger programs. ^Executing any other type of SQL statement 2137 ** does not affect the value returned by sqlite3_total_changes(). 2138 ** 2139 ** ^Changes made as part of [foreign key actions] are included in the 2140 ** count, but those made as part of REPLACE constraint resolution are 2141 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2142 ** are not counted. 2143 ** 2144 ** See also the [sqlite3_changes()] interface, the 2145 ** [count_changes pragma], and the [total_changes() SQL function]. 2146 ** 2147 ** If a separate thread makes changes on the same database connection 2148 ** while [sqlite3_total_changes()] is running then the value 2149 ** returned is unpredictable and not meaningful. 2150 */ 2151 SQLITE_API int sqlite3_total_changes(sqlite3*); 2152 2153 /* 2154 ** CAPI3REF: Interrupt A Long-Running Query 2155 ** METHOD: sqlite3 2156 ** 2157 ** ^This function causes any pending database operation to abort and 2158 ** return at its earliest opportunity. This routine is typically 2159 ** called in response to a user action such as pressing "Cancel" 2160 ** or Ctrl-C where the user wants a long query operation to halt 2161 ** immediately. 2162 ** 2163 ** ^It is safe to call this routine from a thread different from the 2164 ** thread that is currently running the database operation. But it 2165 ** is not safe to call this routine with a [database connection] that 2166 ** is closed or might close before sqlite3_interrupt() returns. 2167 ** 2168 ** ^If an SQL operation is very nearly finished at the time when 2169 ** sqlite3_interrupt() is called, then it might not have an opportunity 2170 ** to be interrupted and might continue to completion. 2171 ** 2172 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2173 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2174 ** that is inside an explicit transaction, then the entire transaction 2175 ** will be rolled back automatically. 2176 ** 2177 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2178 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2179 ** that are started after the sqlite3_interrupt() call and before the 2180 ** running statements reaches zero are interrupted as if they had been 2181 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2182 ** that are started after the running statement count reaches zero are 2183 ** not effected by the sqlite3_interrupt(). 2184 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2185 ** SQL statements is a no-op and has no effect on SQL statements 2186 ** that are started after the sqlite3_interrupt() call returns. 2187 ** 2188 ** If the database connection closes while [sqlite3_interrupt()] 2189 ** is running then bad things will likely happen. 2190 */ 2191 SQLITE_API void sqlite3_interrupt(sqlite3*); 2192 2193 /* 2194 ** CAPI3REF: Determine If An SQL Statement Is Complete 2195 ** 2196 ** These routines are useful during command-line input to determine if the 2197 ** currently entered text seems to form a complete SQL statement or 2198 ** if additional input is needed before sending the text into 2199 ** SQLite for parsing. ^These routines return 1 if the input string 2200 ** appears to be a complete SQL statement. ^A statement is judged to be 2201 ** complete if it ends with a semicolon token and is not a prefix of a 2202 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2203 ** string literals or quoted identifier names or comments are not 2204 ** independent tokens (they are part of the token in which they are 2205 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2206 ** and comments that follow the final semicolon are ignored. 2207 ** 2208 ** ^These routines return 0 if the statement is incomplete. ^If a 2209 ** memory allocation fails, then SQLITE_NOMEM is returned. 2210 ** 2211 ** ^These routines do not parse the SQL statements thus 2212 ** will not detect syntactically incorrect SQL. 2213 ** 2214 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2215 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2216 ** automatically by sqlite3_complete16(). If that initialization fails, 2217 ** then the return value from sqlite3_complete16() will be non-zero 2218 ** regardless of whether or not the input SQL is complete.)^ 2219 ** 2220 ** The input to [sqlite3_complete()] must be a zero-terminated 2221 ** UTF-8 string. 2222 ** 2223 ** The input to [sqlite3_complete16()] must be a zero-terminated 2224 ** UTF-16 string in native byte order. 2225 */ 2226 SQLITE_API int sqlite3_complete(const char *sql); 2227 SQLITE_API int sqlite3_complete16(const void *sql); 2228 2229 /* 2230 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2231 ** KEYWORDS: {busy-handler callback} {busy handler} 2232 ** METHOD: sqlite3 2233 ** 2234 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2235 ** that might be invoked with argument P whenever 2236 ** an attempt is made to access a database table associated with 2237 ** [database connection] D when another thread 2238 ** or process has the table locked. 2239 ** The sqlite3_busy_handler() interface is used to implement 2240 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2241 ** 2242 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2243 ** is returned immediately upon encountering the lock. ^If the busy callback 2244 ** is not NULL, then the callback might be invoked with two arguments. 2245 ** 2246 ** ^The first argument to the busy handler is a copy of the void* pointer which 2247 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2248 ** the busy handler callback is the number of times that the busy handler has 2249 ** been invoked previously for the same locking event. ^If the 2250 ** busy callback returns 0, then no additional attempts are made to 2251 ** access the database and [SQLITE_BUSY] is returned 2252 ** to the application. 2253 ** ^If the callback returns non-zero, then another attempt 2254 ** is made to access the database and the cycle repeats. 2255 ** 2256 ** The presence of a busy handler does not guarantee that it will be invoked 2257 ** when there is lock contention. ^If SQLite determines that invoking the busy 2258 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2259 ** to the application instead of invoking the 2260 ** busy handler. 2261 ** Consider a scenario where one process is holding a read lock that 2262 ** it is trying to promote to a reserved lock and 2263 ** a second process is holding a reserved lock that it is trying 2264 ** to promote to an exclusive lock. The first process cannot proceed 2265 ** because it is blocked by the second and the second process cannot 2266 ** proceed because it is blocked by the first. If both processes 2267 ** invoke the busy handlers, neither will make any progress. Therefore, 2268 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2269 ** will induce the first process to release its read lock and allow 2270 ** the second process to proceed. 2271 ** 2272 ** ^The default busy callback is NULL. 2273 ** 2274 ** ^(There can only be a single busy handler defined for each 2275 ** [database connection]. Setting a new busy handler clears any 2276 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2277 ** or evaluating [PRAGMA busy_timeout=N] will change the 2278 ** busy handler and thus clear any previously set busy handler. 2279 ** 2280 ** The busy callback should not take any actions which modify the 2281 ** database connection that invoked the busy handler. In other words, 2282 ** the busy handler is not reentrant. Any such actions 2283 ** result in undefined behavior. 2284 ** 2285 ** A busy handler must not close the database connection 2286 ** or [prepared statement] that invoked the busy handler. 2287 */ 2288 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2289 2290 /* 2291 ** CAPI3REF: Set A Busy Timeout 2292 ** METHOD: sqlite3 2293 ** 2294 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2295 ** for a specified amount of time when a table is locked. ^The handler 2296 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2297 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2298 ** the handler returns 0 which causes [sqlite3_step()] to return 2299 ** [SQLITE_BUSY]. 2300 ** 2301 ** ^Calling this routine with an argument less than or equal to zero 2302 ** turns off all busy handlers. 2303 ** 2304 ** ^(There can only be a single busy handler for a particular 2305 ** [database connection] at any given moment. If another busy handler 2306 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2307 ** this routine, that other busy handler is cleared.)^ 2308 ** 2309 ** See also: [PRAGMA busy_timeout] 2310 */ 2311 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2312 2313 /* 2314 ** CAPI3REF: Convenience Routines For Running Queries 2315 ** METHOD: sqlite3 2316 ** 2317 ** This is a legacy interface that is preserved for backwards compatibility. 2318 ** Use of this interface is not recommended. 2319 ** 2320 ** Definition: A <b>result table</b> is memory data structure created by the 2321 ** [sqlite3_get_table()] interface. A result table records the 2322 ** complete query results from one or more queries. 2323 ** 2324 ** The table conceptually has a number of rows and columns. But 2325 ** these numbers are not part of the result table itself. These 2326 ** numbers are obtained separately. Let N be the number of rows 2327 ** and M be the number of columns. 2328 ** 2329 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2330 ** There are (N+1)*M elements in the array. The first M pointers point 2331 ** to zero-terminated strings that contain the names of the columns. 2332 ** The remaining entries all point to query results. NULL values result 2333 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2334 ** string representation as returned by [sqlite3_column_text()]. 2335 ** 2336 ** A result table might consist of one or more memory allocations. 2337 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2338 ** A result table should be deallocated using [sqlite3_free_table()]. 2339 ** 2340 ** ^(As an example of the result table format, suppose a query result 2341 ** is as follows: 2342 ** 2343 ** <blockquote><pre> 2344 ** Name | Age 2345 ** ----------------------- 2346 ** Alice | 43 2347 ** Bob | 28 2348 ** Cindy | 21 2349 ** </pre></blockquote> 2350 ** 2351 ** There are two column (M==2) and three rows (N==3). Thus the 2352 ** result table has 8 entries. Suppose the result table is stored 2353 ** in an array names azResult. Then azResult holds this content: 2354 ** 2355 ** <blockquote><pre> 2356 ** azResult[0] = "Name"; 2357 ** azResult[1] = "Age"; 2358 ** azResult[2] = "Alice"; 2359 ** azResult[3] = "43"; 2360 ** azResult[4] = "Bob"; 2361 ** azResult[5] = "28"; 2362 ** azResult[6] = "Cindy"; 2363 ** azResult[7] = "21"; 2364 ** </pre></blockquote>)^ 2365 ** 2366 ** ^The sqlite3_get_table() function evaluates one or more 2367 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2368 ** string of its 2nd parameter and returns a result table to the 2369 ** pointer given in its 3rd parameter. 2370 ** 2371 ** After the application has finished with the result from sqlite3_get_table(), 2372 ** it must pass the result table pointer to sqlite3_free_table() in order to 2373 ** release the memory that was malloced. Because of the way the 2374 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2375 ** function must not try to call [sqlite3_free()] directly. Only 2376 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2377 ** 2378 ** The sqlite3_get_table() interface is implemented as a wrapper around 2379 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2380 ** to any internal data structures of SQLite. It uses only the public 2381 ** interface defined here. As a consequence, errors that occur in the 2382 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2383 ** reflected in subsequent calls to [sqlite3_errcode()] or 2384 ** [sqlite3_errmsg()]. 2385 */ 2386 SQLITE_API int sqlite3_get_table( 2387 sqlite3 *db, /* An open database */ 2388 const char *zSql, /* SQL to be evaluated */ 2389 char ***pazResult, /* Results of the query */ 2390 int *pnRow, /* Number of result rows written here */ 2391 int *pnColumn, /* Number of result columns written here */ 2392 char **pzErrmsg /* Error msg written here */ 2393 ); 2394 SQLITE_API void sqlite3_free_table(char **result); 2395 2396 /* 2397 ** CAPI3REF: Formatted String Printing Functions 2398 ** 2399 ** These routines are work-alikes of the "printf()" family of functions 2400 ** from the standard C library. 2401 ** These routines understand most of the common K&R formatting options, 2402 ** plus some additional non-standard formats, detailed below. 2403 ** Note that some of the more obscure formatting options from recent 2404 ** C-library standards are omitted from this implementation. 2405 ** 2406 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2407 ** results into memory obtained from [sqlite3_malloc()]. 2408 ** The strings returned by these two routines should be 2409 ** released by [sqlite3_free()]. ^Both routines return a 2410 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2411 ** memory to hold the resulting string. 2412 ** 2413 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2414 ** the standard C library. The result is written into the 2415 ** buffer supplied as the second parameter whose size is given by 2416 ** the first parameter. Note that the order of the 2417 ** first two parameters is reversed from snprintf().)^ This is an 2418 ** historical accident that cannot be fixed without breaking 2419 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2420 ** returns a pointer to its buffer instead of the number of 2421 ** characters actually written into the buffer.)^ We admit that 2422 ** the number of characters written would be a more useful return 2423 ** value but we cannot change the implementation of sqlite3_snprintf() 2424 ** now without breaking compatibility. 2425 ** 2426 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2427 ** guarantees that the buffer is always zero-terminated. ^The first 2428 ** parameter "n" is the total size of the buffer, including space for 2429 ** the zero terminator. So the longest string that can be completely 2430 ** written will be n-1 characters. 2431 ** 2432 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2433 ** 2434 ** These routines all implement some additional formatting 2435 ** options that are useful for constructing SQL statements. 2436 ** All of the usual printf() formatting options apply. In addition, there 2437 ** is are "%q", "%Q", "%w" and "%z" options. 2438 ** 2439 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2440 ** string from the argument list. But %q also doubles every '\'' character. 2441 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2442 ** character it escapes that character and allows it to be inserted into 2443 ** the string. 2444 ** 2445 ** For example, assume the string variable zText contains text as follows: 2446 ** 2447 ** <blockquote><pre> 2448 ** char *zText = "It's a happy day!"; 2449 ** </pre></blockquote> 2450 ** 2451 ** One can use this text in an SQL statement as follows: 2452 ** 2453 ** <blockquote><pre> 2454 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2455 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2456 ** sqlite3_free(zSQL); 2457 ** </pre></blockquote> 2458 ** 2459 ** Because the %q format string is used, the '\'' character in zText 2460 ** is escaped and the SQL generated is as follows: 2461 ** 2462 ** <blockquote><pre> 2463 ** INSERT INTO table1 VALUES('It''s a happy day!') 2464 ** </pre></blockquote> 2465 ** 2466 ** This is correct. Had we used %s instead of %q, the generated SQL 2467 ** would have looked like this: 2468 ** 2469 ** <blockquote><pre> 2470 ** INSERT INTO table1 VALUES('It's a happy day!'); 2471 ** </pre></blockquote> 2472 ** 2473 ** This second example is an SQL syntax error. As a general rule you should 2474 ** always use %q instead of %s when inserting text into a string literal. 2475 ** 2476 ** ^(The %Q option works like %q except it also adds single quotes around 2477 ** the outside of the total string. Additionally, if the parameter in the 2478 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2479 ** single quotes).)^ So, for example, one could say: 2480 ** 2481 ** <blockquote><pre> 2482 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2483 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2484 ** sqlite3_free(zSQL); 2485 ** </pre></blockquote> 2486 ** 2487 ** The code above will render a correct SQL statement in the zSQL 2488 ** variable even if the zText variable is a NULL pointer. 2489 ** 2490 ** ^(The "%w" formatting option is like "%q" except that it expects to 2491 ** be contained within double-quotes instead of single quotes, and it 2492 ** escapes the double-quote character instead of the single-quote 2493 ** character.)^ The "%w" formatting option is intended for safely inserting 2494 ** table and column names into a constructed SQL statement. 2495 ** 2496 ** ^(The "%z" formatting option works like "%s" but with the 2497 ** addition that after the string has been read and copied into 2498 ** the result, [sqlite3_free()] is called on the input string.)^ 2499 */ 2500 SQLITE_API char *sqlite3_mprintf(const char*,...); 2501 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2502 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2503 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2504 2505 /* 2506 ** CAPI3REF: Memory Allocation Subsystem 2507 ** 2508 ** The SQLite core uses these three routines for all of its own 2509 ** internal memory allocation needs. "Core" in the previous sentence 2510 ** does not include operating-system specific VFS implementation. The 2511 ** Windows VFS uses native malloc() and free() for some operations. 2512 ** 2513 ** ^The sqlite3_malloc() routine returns a pointer to a block 2514 ** of memory at least N bytes in length, where N is the parameter. 2515 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2516 ** memory, it returns a NULL pointer. ^If the parameter N to 2517 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2518 ** a NULL pointer. 2519 ** 2520 ** ^The sqlite3_malloc64(N) routine works just like 2521 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2522 ** of a signed 32-bit integer. 2523 ** 2524 ** ^Calling sqlite3_free() with a pointer previously returned 2525 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2526 ** that it might be reused. ^The sqlite3_free() routine is 2527 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2528 ** to sqlite3_free() is harmless. After being freed, memory 2529 ** should neither be read nor written. Even reading previously freed 2530 ** memory might result in a segmentation fault or other severe error. 2531 ** Memory corruption, a segmentation fault, or other severe error 2532 ** might result if sqlite3_free() is called with a non-NULL pointer that 2533 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2534 ** 2535 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2536 ** prior memory allocation X to be at least N bytes. 2537 ** ^If the X parameter to sqlite3_realloc(X,N) 2538 ** is a NULL pointer then its behavior is identical to calling 2539 ** sqlite3_malloc(N). 2540 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2541 ** negative then the behavior is exactly the same as calling 2542 ** sqlite3_free(X). 2543 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2544 ** of at least N bytes in size or NULL if insufficient memory is available. 2545 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2546 ** of the prior allocation are copied into the beginning of buffer returned 2547 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2548 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2549 ** prior allocation is not freed. 2550 ** 2551 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2552 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2553 ** of a 32-bit signed integer. 2554 ** 2555 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2556 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2557 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2558 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2559 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2560 ** sqlite3_msize(X) returns zero. If X points to something that is not 2561 ** the beginning of memory allocation, or if it points to a formerly 2562 ** valid memory allocation that has now been freed, then the behavior 2563 ** of sqlite3_msize(X) is undefined and possibly harmful. 2564 ** 2565 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2566 ** sqlite3_malloc64(), and sqlite3_realloc64() 2567 ** is always aligned to at least an 8 byte boundary, or to a 2568 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2569 ** option is used. 2570 ** 2571 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2572 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2573 ** implementation of these routines to be omitted. That capability 2574 ** is no longer provided. Only built-in memory allocators can be used. 2575 ** 2576 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2577 ** the system malloc() and free() directly when converting 2578 ** filenames between the UTF-8 encoding used by SQLite 2579 ** and whatever filename encoding is used by the particular Windows 2580 ** installation. Memory allocation errors were detected, but 2581 ** they were reported back as [SQLITE_CANTOPEN] or 2582 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2583 ** 2584 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2585 ** must be either NULL or else pointers obtained from a prior 2586 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2587 ** not yet been released. 2588 ** 2589 ** The application must not read or write any part of 2590 ** a block of memory after it has been released using 2591 ** [sqlite3_free()] or [sqlite3_realloc()]. 2592 */ 2593 SQLITE_API void *sqlite3_malloc(int); 2594 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2595 SQLITE_API void *sqlite3_realloc(void*, int); 2596 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2597 SQLITE_API void sqlite3_free(void*); 2598 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2599 2600 /* 2601 ** CAPI3REF: Memory Allocator Statistics 2602 ** 2603 ** SQLite provides these two interfaces for reporting on the status 2604 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2605 ** routines, which form the built-in memory allocation subsystem. 2606 ** 2607 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2608 ** of memory currently outstanding (malloced but not freed). 2609 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2610 ** value of [sqlite3_memory_used()] since the high-water mark 2611 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2612 ** [sqlite3_memory_highwater()] include any overhead 2613 ** added by SQLite in its implementation of [sqlite3_malloc()], 2614 ** but not overhead added by the any underlying system library 2615 ** routines that [sqlite3_malloc()] may call. 2616 ** 2617 ** ^The memory high-water mark is reset to the current value of 2618 ** [sqlite3_memory_used()] if and only if the parameter to 2619 ** [sqlite3_memory_highwater()] is true. ^The value returned 2620 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2621 ** prior to the reset. 2622 */ 2623 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2624 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2625 2626 /* 2627 ** CAPI3REF: Pseudo-Random Number Generator 2628 ** 2629 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2630 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2631 ** already uses the largest possible [ROWID]. The PRNG is also used for 2632 ** the build-in random() and randomblob() SQL functions. This interface allows 2633 ** applications to access the same PRNG for other purposes. 2634 ** 2635 ** ^A call to this routine stores N bytes of randomness into buffer P. 2636 ** ^The P parameter can be a NULL pointer. 2637 ** 2638 ** ^If this routine has not been previously called or if the previous 2639 ** call had N less than one or a NULL pointer for P, then the PRNG is 2640 ** seeded using randomness obtained from the xRandomness method of 2641 ** the default [sqlite3_vfs] object. 2642 ** ^If the previous call to this routine had an N of 1 or more and a 2643 ** non-NULL P then the pseudo-randomness is generated 2644 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2645 ** method. 2646 */ 2647 SQLITE_API void sqlite3_randomness(int N, void *P); 2648 2649 /* 2650 ** CAPI3REF: Compile-Time Authorization Callbacks 2651 ** METHOD: sqlite3 2652 ** 2653 ** ^This routine registers an authorizer callback with a particular 2654 ** [database connection], supplied in the first argument. 2655 ** ^The authorizer callback is invoked as SQL statements are being compiled 2656 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2657 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2658 ** points during the compilation process, as logic is being created 2659 ** to perform various actions, the authorizer callback is invoked to 2660 ** see if those actions are allowed. ^The authorizer callback should 2661 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2662 ** specific action but allow the SQL statement to continue to be 2663 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2664 ** rejected with an error. ^If the authorizer callback returns 2665 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2666 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2667 ** the authorizer will fail with an error message. 2668 ** 2669 ** When the callback returns [SQLITE_OK], that means the operation 2670 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2671 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2672 ** authorizer will fail with an error message explaining that 2673 ** access is denied. 2674 ** 2675 ** ^The first parameter to the authorizer callback is a copy of the third 2676 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2677 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2678 ** the particular action to be authorized. ^The third through sixth parameters 2679 ** to the callback are zero-terminated strings that contain additional 2680 ** details about the action to be authorized. 2681 ** 2682 ** ^If the action code is [SQLITE_READ] 2683 ** and the callback returns [SQLITE_IGNORE] then the 2684 ** [prepared statement] statement is constructed to substitute 2685 ** a NULL value in place of the table column that would have 2686 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2687 ** return can be used to deny an untrusted user access to individual 2688 ** columns of a table. 2689 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2690 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2691 ** [truncate optimization] is disabled and all rows are deleted individually. 2692 ** 2693 ** An authorizer is used when [sqlite3_prepare | preparing] 2694 ** SQL statements from an untrusted source, to ensure that the SQL statements 2695 ** do not try to access data they are not allowed to see, or that they do not 2696 ** try to execute malicious statements that damage the database. For 2697 ** example, an application may allow a user to enter arbitrary 2698 ** SQL queries for evaluation by a database. But the application does 2699 ** not want the user to be able to make arbitrary changes to the 2700 ** database. An authorizer could then be put in place while the 2701 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2702 ** disallows everything except [SELECT] statements. 2703 ** 2704 ** Applications that need to process SQL from untrusted sources 2705 ** might also consider lowering resource limits using [sqlite3_limit()] 2706 ** and limiting database size using the [max_page_count] [PRAGMA] 2707 ** in addition to using an authorizer. 2708 ** 2709 ** ^(Only a single authorizer can be in place on a database connection 2710 ** at a time. Each call to sqlite3_set_authorizer overrides the 2711 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2712 ** The authorizer is disabled by default. 2713 ** 2714 ** The authorizer callback must not do anything that will modify 2715 ** the database connection that invoked the authorizer callback. 2716 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2717 ** database connections for the meaning of "modify" in this paragraph. 2718 ** 2719 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2720 ** statement might be re-prepared during [sqlite3_step()] due to a 2721 ** schema change. Hence, the application should ensure that the 2722 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2723 ** 2724 ** ^Note that the authorizer callback is invoked only during 2725 ** [sqlite3_prepare()] or its variants. Authorization is not 2726 ** performed during statement evaluation in [sqlite3_step()], unless 2727 ** as stated in the previous paragraph, sqlite3_step() invokes 2728 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2729 */ 2730 SQLITE_API int sqlite3_set_authorizer( 2731 sqlite3*, 2732 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2733 void *pUserData 2734 ); 2735 2736 /* 2737 ** CAPI3REF: Authorizer Return Codes 2738 ** 2739 ** The [sqlite3_set_authorizer | authorizer callback function] must 2740 ** return either [SQLITE_OK] or one of these two constants in order 2741 ** to signal SQLite whether or not the action is permitted. See the 2742 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2743 ** information. 2744 ** 2745 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2746 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2747 */ 2748 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2749 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2750 2751 /* 2752 ** CAPI3REF: Authorizer Action Codes 2753 ** 2754 ** The [sqlite3_set_authorizer()] interface registers a callback function 2755 ** that is invoked to authorize certain SQL statement actions. The 2756 ** second parameter to the callback is an integer code that specifies 2757 ** what action is being authorized. These are the integer action codes that 2758 ** the authorizer callback may be passed. 2759 ** 2760 ** These action code values signify what kind of operation is to be 2761 ** authorized. The 3rd and 4th parameters to the authorization 2762 ** callback function will be parameters or NULL depending on which of these 2763 ** codes is used as the second parameter. ^(The 5th parameter to the 2764 ** authorizer callback is the name of the database ("main", "temp", 2765 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2766 ** is the name of the inner-most trigger or view that is responsible for 2767 ** the access attempt or NULL if this access attempt is directly from 2768 ** top-level SQL code. 2769 */ 2770 /******************************************* 3rd ************ 4th ***********/ 2771 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2772 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2773 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2774 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2775 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2776 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2777 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2778 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2779 #define SQLITE_DELETE 9 /* Table Name NULL */ 2780 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2781 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2782 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2783 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2784 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2785 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2786 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2787 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2788 #define SQLITE_INSERT 18 /* Table Name NULL */ 2789 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2790 #define SQLITE_READ 20 /* Table Name Column Name */ 2791 #define SQLITE_SELECT 21 /* NULL NULL */ 2792 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2793 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2794 #define SQLITE_ATTACH 24 /* Filename NULL */ 2795 #define SQLITE_DETACH 25 /* Database Name NULL */ 2796 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2797 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2798 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2799 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2800 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2801 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2802 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2803 #define SQLITE_COPY 0 /* No longer used */ 2804 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2805 2806 /* 2807 ** CAPI3REF: Tracing And Profiling Functions 2808 ** METHOD: sqlite3 2809 ** 2810 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2811 ** instead of the routines described here. 2812 ** 2813 ** These routines register callback functions that can be used for 2814 ** tracing and profiling the execution of SQL statements. 2815 ** 2816 ** ^The callback function registered by sqlite3_trace() is invoked at 2817 ** various times when an SQL statement is being run by [sqlite3_step()]. 2818 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2819 ** SQL statement text as the statement first begins executing. 2820 ** ^(Additional sqlite3_trace() callbacks might occur 2821 ** as each triggered subprogram is entered. The callbacks for triggers 2822 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2823 ** 2824 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2825 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2826 ** 2827 ** ^The callback function registered by sqlite3_profile() is invoked 2828 ** as each SQL statement finishes. ^The profile callback contains 2829 ** the original statement text and an estimate of wall-clock time 2830 ** of how long that statement took to run. ^The profile callback 2831 ** time is in units of nanoseconds, however the current implementation 2832 ** is only capable of millisecond resolution so the six least significant 2833 ** digits in the time are meaningless. Future versions of SQLite 2834 ** might provide greater resolution on the profiler callback. The 2835 ** sqlite3_profile() function is considered experimental and is 2836 ** subject to change in future versions of SQLite. 2837 */ 2838 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2839 void(*xTrace)(void*,const char*), void*); 2840 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2841 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2842 2843 /* 2844 ** CAPI3REF: SQL Trace Event Codes 2845 ** KEYWORDS: SQLITE_TRACE 2846 ** 2847 ** These constants identify classes of events that can be monitored 2848 ** using the [sqlite3_trace_v2()] tracing logic. The third argument 2849 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2850 ** the following constants. ^The first argument to the trace callback 2851 ** is one of the following constants. 2852 ** 2853 ** New tracing constants may be added in future releases. 2854 ** 2855 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2856 ** ^The T argument is one of the integer type codes above. 2857 ** ^The C argument is a copy of the context pointer passed in as the 2858 ** fourth argument to [sqlite3_trace_v2()]. 2859 ** The P and X arguments are pointers whose meanings depend on T. 2860 ** 2861 ** <dl> 2862 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2863 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2864 ** first begins running and possibly at other times during the 2865 ** execution of the prepared statement, such as at the start of each 2866 ** trigger subprogram. ^The P argument is a pointer to the 2867 ** [prepared statement]. ^The X argument is a pointer to a string which 2868 ** is the unexpanded SQL text of the prepared statement or an SQL comment 2869 ** that indicates the invocation of a trigger. ^The callback can compute 2870 ** the same text that would have been returned by the legacy [sqlite3_trace()] 2871 ** interface by using the X argument when X begins with "--" and invoking 2872 ** [sqlite3_expanded_sql(P)] otherwise. 2873 ** 2874 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2875 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2876 ** information as is provided by the [sqlite3_profile()] callback. 2877 ** ^The P argument is a pointer to the [prepared statement] and the 2878 ** X argument points to a 64-bit integer which is the estimated of 2879 ** the number of nanosecond that the prepared statement took to run. 2880 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2881 ** 2882 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2883 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2884 ** statement generates a single row of result. 2885 ** ^The P argument is a pointer to the [prepared statement] and the 2886 ** X argument is unused. 2887 ** 2888 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2889 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2890 ** connection closes. 2891 ** ^The P argument is a pointer to the [database connection] object 2892 ** and the X argument is unused. 2893 ** </dl> 2894 */ 2895 #define SQLITE_TRACE_STMT 0x01 2896 #define SQLITE_TRACE_PROFILE 0x02 2897 #define SQLITE_TRACE_ROW 0x04 2898 #define SQLITE_TRACE_CLOSE 0x08 2899 2900 /* 2901 ** CAPI3REF: SQL Trace Hook 2902 ** METHOD: sqlite3 2903 ** 2904 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2905 ** function X against [database connection] D, using property mask M 2906 ** and context pointer P. ^If the X callback is 2907 ** NULL or if the M mask is zero, then tracing is disabled. The 2908 ** M argument should be the bitwise OR-ed combination of 2909 ** zero or more [SQLITE_TRACE] constants. 2910 ** 2911 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2912 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2913 ** 2914 ** ^The X callback is invoked whenever any of the events identified by 2915 ** mask M occur. ^The integer return value from the callback is currently 2916 ** ignored, though this may change in future releases. Callback 2917 ** implementations should return zero to ensure future compatibility. 2918 ** 2919 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2920 ** ^The T argument is one of the [SQLITE_TRACE] 2921 ** constants to indicate why the callback was invoked. 2922 ** ^The C argument is a copy of the context pointer. 2923 ** The P and X arguments are pointers whose meanings depend on T. 2924 ** 2925 ** The sqlite3_trace_v2() interface is intended to replace the legacy 2926 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2927 ** are deprecated. 2928 */ 2929 SQLITE_API int sqlite3_trace_v2( 2930 sqlite3*, 2931 unsigned uMask, 2932 int(*xCallback)(unsigned,void*,void*,void*), 2933 void *pCtx 2934 ); 2935 2936 /* 2937 ** CAPI3REF: Query Progress Callbacks 2938 ** METHOD: sqlite3 2939 ** 2940 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2941 ** function X to be invoked periodically during long running calls to 2942 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2943 ** database connection D. An example use for this 2944 ** interface is to keep a GUI updated during a large query. 2945 ** 2946 ** ^The parameter P is passed through as the only parameter to the 2947 ** callback function X. ^The parameter N is the approximate number of 2948 ** [virtual machine instructions] that are evaluated between successive 2949 ** invocations of the callback X. ^If N is less than one then the progress 2950 ** handler is disabled. 2951 ** 2952 ** ^Only a single progress handler may be defined at one time per 2953 ** [database connection]; setting a new progress handler cancels the 2954 ** old one. ^Setting parameter X to NULL disables the progress handler. 2955 ** ^The progress handler is also disabled by setting N to a value less 2956 ** than 1. 2957 ** 2958 ** ^If the progress callback returns non-zero, the operation is 2959 ** interrupted. This feature can be used to implement a 2960 ** "Cancel" button on a GUI progress dialog box. 2961 ** 2962 ** The progress handler callback must not do anything that will modify 2963 ** the database connection that invoked the progress handler. 2964 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2965 ** database connections for the meaning of "modify" in this paragraph. 2966 ** 2967 */ 2968 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2969 2970 /* 2971 ** CAPI3REF: Opening A New Database Connection 2972 ** CONSTRUCTOR: sqlite3 2973 ** 2974 ** ^These routines open an SQLite database file as specified by the 2975 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2976 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2977 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2978 ** returned in *ppDb, even if an error occurs. The only exception is that 2979 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2980 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2981 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2982 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2983 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2984 ** an English language description of the error following a failure of any 2985 ** of the sqlite3_open() routines. 2986 ** 2987 ** ^The default encoding will be UTF-8 for databases created using 2988 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2989 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2990 ** 2991 ** Whether or not an error occurs when it is opened, resources 2992 ** associated with the [database connection] handle should be released by 2993 ** passing it to [sqlite3_close()] when it is no longer required. 2994 ** 2995 ** The sqlite3_open_v2() interface works like sqlite3_open() 2996 ** except that it accepts two additional parameters for additional control 2997 ** over the new database connection. ^(The flags parameter to 2998 ** sqlite3_open_v2() can take one of 2999 ** the following three values, optionally combined with the 3000 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3001 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3002 ** 3003 ** <dl> 3004 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3005 ** <dd>The database is opened in read-only mode. If the database does not 3006 ** already exist, an error is returned.</dd>)^ 3007 ** 3008 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3009 ** <dd>The database is opened for reading and writing if possible, or reading 3010 ** only if the file is write protected by the operating system. In either 3011 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3012 ** 3013 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3014 ** <dd>The database is opened for reading and writing, and is created if 3015 ** it does not already exist. This is the behavior that is always used for 3016 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3017 ** </dl> 3018 ** 3019 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3020 ** combinations shown above optionally combined with other 3021 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3022 ** then the behavior is undefined. 3023 ** 3024 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3025 ** opens in the multi-thread [threading mode] as long as the single-thread 3026 ** mode has not been set at compile-time or start-time. ^If the 3027 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3028 ** in the serialized [threading mode] unless single-thread was 3029 ** previously selected at compile-time or start-time. 3030 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3031 ** eligible to use [shared cache mode], regardless of whether or not shared 3032 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3033 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3034 ** participate in [shared cache mode] even if it is enabled. 3035 ** 3036 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3037 ** [sqlite3_vfs] object that defines the operating system interface that 3038 ** the new database connection should use. ^If the fourth parameter is 3039 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3040 ** 3041 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3042 ** is created for the connection. ^This in-memory database will vanish when 3043 ** the database connection is closed. Future versions of SQLite might 3044 ** make use of additional special filenames that begin with the ":" character. 3045 ** It is recommended that when a database filename actually does begin with 3046 ** a ":" character you should prefix the filename with a pathname such as 3047 ** "./" to avoid ambiguity. 3048 ** 3049 ** ^If the filename is an empty string, then a private, temporary 3050 ** on-disk database will be created. ^This private database will be 3051 ** automatically deleted as soon as the database connection is closed. 3052 ** 3053 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3054 ** 3055 ** ^If [URI filename] interpretation is enabled, and the filename argument 3056 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3057 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3058 ** set in the fourth argument to sqlite3_open_v2(), or if it has 3059 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3060 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3061 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 3062 ** by default, but future releases of SQLite might enable URI filename 3063 ** interpretation by default. See "[URI filenames]" for additional 3064 ** information. 3065 ** 3066 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3067 ** authority, then it must be either an empty string or the string 3068 ** "localhost". ^If the authority is not an empty string or "localhost", an 3069 ** error is returned to the caller. ^The fragment component of a URI, if 3070 ** present, is ignored. 3071 ** 3072 ** ^SQLite uses the path component of the URI as the name of the disk file 3073 ** which contains the database. ^If the path begins with a '/' character, 3074 ** then it is interpreted as an absolute path. ^If the path does not begin 3075 ** with a '/' (meaning that the authority section is omitted from the URI) 3076 ** then the path is interpreted as a relative path. 3077 ** ^(On windows, the first component of an absolute path 3078 ** is a drive specification (e.g. "C:").)^ 3079 ** 3080 ** [[core URI query parameters]] 3081 ** The query component of a URI may contain parameters that are interpreted 3082 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3083 ** SQLite and its built-in [VFSes] interpret the 3084 ** following query parameters: 3085 ** 3086 ** <ul> 3087 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3088 ** a VFS object that provides the operating system interface that should 3089 ** be used to access the database file on disk. ^If this option is set to 3090 ** an empty string the default VFS object is used. ^Specifying an unknown 3091 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3092 ** present, then the VFS specified by the option takes precedence over 3093 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3094 ** 3095 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3096 ** "rwc", or "memory". Attempting to set it to any other value is 3097 ** an error)^. 3098 ** ^If "ro" is specified, then the database is opened for read-only 3099 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3100 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3101 ** "rw", then the database is opened for read-write (but not create) 3102 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3103 ** been set. ^Value "rwc" is equivalent to setting both 3104 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3105 ** set to "memory" then a pure [in-memory database] that never reads 3106 ** or writes from disk is used. ^It is an error to specify a value for 3107 ** the mode parameter that is less restrictive than that specified by 3108 ** the flags passed in the third parameter to sqlite3_open_v2(). 3109 ** 3110 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3111 ** "private". ^Setting it to "shared" is equivalent to setting the 3112 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3113 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3114 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3115 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3116 ** a URI filename, its value overrides any behavior requested by setting 3117 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3118 ** 3119 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3120 ** [powersafe overwrite] property does or does not apply to the 3121 ** storage media on which the database file resides. 3122 ** 3123 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3124 ** which if set disables file locking in rollback journal modes. This 3125 ** is useful for accessing a database on a filesystem that does not 3126 ** support locking. Caution: Database corruption might result if two 3127 ** or more processes write to the same database and any one of those 3128 ** processes uses nolock=1. 3129 ** 3130 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3131 ** parameter that indicates that the database file is stored on 3132 ** read-only media. ^When immutable is set, SQLite assumes that the 3133 ** database file cannot be changed, even by a process with higher 3134 ** privilege, and so the database is opened read-only and all locking 3135 ** and change detection is disabled. Caution: Setting the immutable 3136 ** property on a database file that does in fact change can result 3137 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3138 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3139 ** 3140 ** </ul> 3141 ** 3142 ** ^Specifying an unknown parameter in the query component of a URI is not an 3143 ** error. Future versions of SQLite might understand additional query 3144 ** parameters. See "[query parameters with special meaning to SQLite]" for 3145 ** additional information. 3146 ** 3147 ** [[URI filename examples]] <h3>URI filename examples</h3> 3148 ** 3149 ** <table border="1" align=center cellpadding=5> 3150 ** <tr><th> URI filenames <th> Results 3151 ** <tr><td> file:data.db <td> 3152 ** Open the file "data.db" in the current directory. 3153 ** <tr><td> file:/home/fred/data.db<br> 3154 ** file:///home/fred/data.db <br> 3155 ** file://localhost/home/fred/data.db <br> <td> 3156 ** Open the database file "/home/fred/data.db". 3157 ** <tr><td> file://darkstar/home/fred/data.db <td> 3158 ** An error. "darkstar" is not a recognized authority. 3159 ** <tr><td style="white-space:nowrap"> 3160 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3161 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3162 ** C:. Note that the %20 escaping in this example is not strictly 3163 ** necessary - space characters can be used literally 3164 ** in URI filenames. 3165 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3166 ** Open file "data.db" in the current directory for read-only access. 3167 ** Regardless of whether or not shared-cache mode is enabled by 3168 ** default, use a private cache. 3169 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3170 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3171 ** that uses dot-files in place of posix advisory locking. 3172 ** <tr><td> file:data.db?mode=readonly <td> 3173 ** An error. "readonly" is not a valid option for the "mode" parameter. 3174 ** </table> 3175 ** 3176 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3177 ** query components of a URI. A hexadecimal escape sequence consists of a 3178 ** percent sign - "%" - followed by exactly two hexadecimal digits 3179 ** specifying an octet value. ^Before the path or query components of a 3180 ** URI filename are interpreted, they are encoded using UTF-8 and all 3181 ** hexadecimal escape sequences replaced by a single byte containing the 3182 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3183 ** the results are undefined. 3184 ** 3185 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3186 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3187 ** codepage is currently defined. Filenames containing international 3188 ** characters must be converted to UTF-8 prior to passing them into 3189 ** sqlite3_open() or sqlite3_open_v2(). 3190 ** 3191 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3192 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3193 ** features that require the use of temporary files may fail. 3194 ** 3195 ** See also: [sqlite3_temp_directory] 3196 */ 3197 SQLITE_API int sqlite3_open( 3198 const char *filename, /* Database filename (UTF-8) */ 3199 sqlite3 **ppDb /* OUT: SQLite db handle */ 3200 ); 3201 SQLITE_API int sqlite3_open16( 3202 const void *filename, /* Database filename (UTF-16) */ 3203 sqlite3 **ppDb /* OUT: SQLite db handle */ 3204 ); 3205 SQLITE_API int sqlite3_open_v2( 3206 const char *filename, /* Database filename (UTF-8) */ 3207 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3208 int flags, /* Flags */ 3209 const char *zVfs /* Name of VFS module to use */ 3210 ); 3211 3212 /* 3213 ** CAPI3REF: Obtain Values For URI Parameters 3214 ** 3215 ** These are utility routines, useful to VFS implementations, that check 3216 ** to see if a database file was a URI that contained a specific query 3217 ** parameter, and if so obtains the value of that query parameter. 3218 ** 3219 ** If F is the database filename pointer passed into the xOpen() method of 3220 ** a VFS implementation when the flags parameter to xOpen() has one or 3221 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3222 ** P is the name of the query parameter, then 3223 ** sqlite3_uri_parameter(F,P) returns the value of the P 3224 ** parameter if it exists or a NULL pointer if P does not appear as a 3225 ** query parameter on F. If P is a query parameter of F 3226 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3227 ** a pointer to an empty string. 3228 ** 3229 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3230 ** parameter and returns true (1) or false (0) according to the value 3231 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3232 ** value of query parameter P is one of "yes", "true", or "on" in any 3233 ** case or if the value begins with a non-zero number. The 3234 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3235 ** query parameter P is one of "no", "false", or "off" in any case or 3236 ** if the value begins with a numeric zero. If P is not a query 3237 ** parameter on F or if the value of P is does not match any of the 3238 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3239 ** 3240 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3241 ** 64-bit signed integer and returns that integer, or D if P does not 3242 ** exist. If the value of P is something other than an integer, then 3243 ** zero is returned. 3244 ** 3245 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3246 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3247 ** is not a database file pathname pointer that SQLite passed into the xOpen 3248 ** VFS method, then the behavior of this routine is undefined and probably 3249 ** undesirable. 3250 */ 3251 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3252 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3253 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3254 3255 3256 /* 3257 ** CAPI3REF: Error Codes And Messages 3258 ** METHOD: sqlite3 3259 ** 3260 ** ^If the most recent sqlite3_* API call associated with 3261 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3262 ** returns the numeric [result code] or [extended result code] for that 3263 ** API call. 3264 ** If the most recent API call was successful, 3265 ** then the return value from sqlite3_errcode() is undefined. 3266 ** ^The sqlite3_extended_errcode() 3267 ** interface is the same except that it always returns the 3268 ** [extended result code] even when extended result codes are 3269 ** disabled. 3270 ** 3271 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3272 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3273 ** ^(Memory to hold the error message string is managed internally. 3274 ** The application does not need to worry about freeing the result. 3275 ** However, the error string might be overwritten or deallocated by 3276 ** subsequent calls to other SQLite interface functions.)^ 3277 ** 3278 ** ^The sqlite3_errstr() interface returns the English-language text 3279 ** that describes the [result code], as UTF-8. 3280 ** ^(Memory to hold the error message string is managed internally 3281 ** and must not be freed by the application)^. 3282 ** 3283 ** When the serialized [threading mode] is in use, it might be the 3284 ** case that a second error occurs on a separate thread in between 3285 ** the time of the first error and the call to these interfaces. 3286 ** When that happens, the second error will be reported since these 3287 ** interfaces always report the most recent result. To avoid 3288 ** this, each thread can obtain exclusive use of the [database connection] D 3289 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3290 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3291 ** all calls to the interfaces listed here are completed. 3292 ** 3293 ** If an interface fails with SQLITE_MISUSE, that means the interface 3294 ** was invoked incorrectly by the application. In that case, the 3295 ** error code and message may or may not be set. 3296 */ 3297 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3298 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3299 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3300 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3301 SQLITE_API const char *sqlite3_errstr(int); 3302 3303 /* 3304 ** CAPI3REF: Prepared Statement Object 3305 ** KEYWORDS: {prepared statement} {prepared statements} 3306 ** 3307 ** An instance of this object represents a single SQL statement that 3308 ** has been compiled into binary form and is ready to be evaluated. 3309 ** 3310 ** Think of each SQL statement as a separate computer program. The 3311 ** original SQL text is source code. A prepared statement object 3312 ** is the compiled object code. All SQL must be converted into a 3313 ** prepared statement before it can be run. 3314 ** 3315 ** The life-cycle of a prepared statement object usually goes like this: 3316 ** 3317 ** <ol> 3318 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3319 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3320 ** interfaces. 3321 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3322 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3323 ** to step 2. Do this zero or more times. 3324 ** <li> Destroy the object using [sqlite3_finalize()]. 3325 ** </ol> 3326 */ 3327 typedef struct sqlite3_stmt sqlite3_stmt; 3328 3329 /* 3330 ** CAPI3REF: Run-time Limits 3331 ** METHOD: sqlite3 3332 ** 3333 ** ^(This interface allows the size of various constructs to be limited 3334 ** on a connection by connection basis. The first parameter is the 3335 ** [database connection] whose limit is to be set or queried. The 3336 ** second parameter is one of the [limit categories] that define a 3337 ** class of constructs to be size limited. The third parameter is the 3338 ** new limit for that construct.)^ 3339 ** 3340 ** ^If the new limit is a negative number, the limit is unchanged. 3341 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3342 ** [limits | hard upper bound] 3343 ** set at compile-time by a C preprocessor macro called 3344 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3345 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3346 ** ^Attempts to increase a limit above its hard upper bound are 3347 ** silently truncated to the hard upper bound. 3348 ** 3349 ** ^Regardless of whether or not the limit was changed, the 3350 ** [sqlite3_limit()] interface returns the prior value of the limit. 3351 ** ^Hence, to find the current value of a limit without changing it, 3352 ** simply invoke this interface with the third parameter set to -1. 3353 ** 3354 ** Run-time limits are intended for use in applications that manage 3355 ** both their own internal database and also databases that are controlled 3356 ** by untrusted external sources. An example application might be a 3357 ** web browser that has its own databases for storing history and 3358 ** separate databases controlled by JavaScript applications downloaded 3359 ** off the Internet. The internal databases can be given the 3360 ** large, default limits. Databases managed by external sources can 3361 ** be given much smaller limits designed to prevent a denial of service 3362 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3363 ** interface to further control untrusted SQL. The size of the database 3364 ** created by an untrusted script can be contained using the 3365 ** [max_page_count] [PRAGMA]. 3366 ** 3367 ** New run-time limit categories may be added in future releases. 3368 */ 3369 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3370 3371 /* 3372 ** CAPI3REF: Run-Time Limit Categories 3373 ** KEYWORDS: {limit category} {*limit categories} 3374 ** 3375 ** These constants define various performance limits 3376 ** that can be lowered at run-time using [sqlite3_limit()]. 3377 ** The synopsis of the meanings of the various limits is shown below. 3378 ** Additional information is available at [limits | Limits in SQLite]. 3379 ** 3380 ** <dl> 3381 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3382 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3383 ** 3384 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3385 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3386 ** 3387 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3388 ** <dd>The maximum number of columns in a table definition or in the 3389 ** result set of a [SELECT] or the maximum number of columns in an index 3390 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3391 ** 3392 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3393 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3394 ** 3395 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3396 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3397 ** 3398 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3399 ** <dd>The maximum number of instructions in a virtual machine program 3400 ** used to implement an SQL statement. This limit is not currently 3401 ** enforced, though that might be added in some future release of 3402 ** SQLite.</dd>)^ 3403 ** 3404 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3405 ** <dd>The maximum number of arguments on a function.</dd>)^ 3406 ** 3407 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3408 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3409 ** 3410 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3411 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3412 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3413 ** [GLOB] operators.</dd>)^ 3414 ** 3415 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3416 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3417 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3418 ** 3419 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3420 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3421 ** 3422 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3423 ** <dd>The maximum number of auxiliary worker threads that a single 3424 ** [prepared statement] may start.</dd>)^ 3425 ** </dl> 3426 */ 3427 #define SQLITE_LIMIT_LENGTH 0 3428 #define SQLITE_LIMIT_SQL_LENGTH 1 3429 #define SQLITE_LIMIT_COLUMN 2 3430 #define SQLITE_LIMIT_EXPR_DEPTH 3 3431 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3432 #define SQLITE_LIMIT_VDBE_OP 5 3433 #define SQLITE_LIMIT_FUNCTION_ARG 6 3434 #define SQLITE_LIMIT_ATTACHED 7 3435 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3436 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3437 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3438 #define SQLITE_LIMIT_WORKER_THREADS 11 3439 3440 /* 3441 ** CAPI3REF: Compiling An SQL Statement 3442 ** KEYWORDS: {SQL statement compiler} 3443 ** METHOD: sqlite3 3444 ** CONSTRUCTOR: sqlite3_stmt 3445 ** 3446 ** To execute an SQL query, it must first be compiled into a byte-code 3447 ** program using one of these routines. 3448 ** 3449 ** The first argument, "db", is a [database connection] obtained from a 3450 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3451 ** [sqlite3_open16()]. The database connection must not have been closed. 3452 ** 3453 ** The second argument, "zSql", is the statement to be compiled, encoded 3454 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3455 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3456 ** use UTF-16. 3457 ** 3458 ** ^If the nByte argument is negative, then zSql is read up to the 3459 ** first zero terminator. ^If nByte is positive, then it is the 3460 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3461 ** statement is generated. 3462 ** If the caller knows that the supplied string is nul-terminated, then 3463 ** there is a small performance advantage to passing an nByte parameter that 3464 ** is the number of bytes in the input string <i>including</i> 3465 ** the nul-terminator. 3466 ** 3467 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3468 ** past the end of the first SQL statement in zSql. These routines only 3469 ** compile the first statement in zSql, so *pzTail is left pointing to 3470 ** what remains uncompiled. 3471 ** 3472 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3473 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3474 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3475 ** string or a comment) then *ppStmt is set to NULL. 3476 ** The calling procedure is responsible for deleting the compiled 3477 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3478 ** ppStmt may not be NULL. 3479 ** 3480 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3481 ** otherwise an [error code] is returned. 3482 ** 3483 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3484 ** recommended for all new programs. The two older interfaces are retained 3485 ** for backwards compatibility, but their use is discouraged. 3486 ** ^In the "v2" interfaces, the prepared statement 3487 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3488 ** original SQL text. This causes the [sqlite3_step()] interface to 3489 ** behave differently in three ways: 3490 ** 3491 ** <ol> 3492 ** <li> 3493 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3494 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3495 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3496 ** retries will occur before sqlite3_step() gives up and returns an error. 3497 ** </li> 3498 ** 3499 ** <li> 3500 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3501 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3502 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3503 ** and the application would have to make a second call to [sqlite3_reset()] 3504 ** in order to find the underlying cause of the problem. With the "v2" prepare 3505 ** interfaces, the underlying reason for the error is returned immediately. 3506 ** </li> 3507 ** 3508 ** <li> 3509 ** ^If the specific value bound to [parameter | host parameter] in the 3510 ** WHERE clause might influence the choice of query plan for a statement, 3511 ** then the statement will be automatically recompiled, as if there had been 3512 ** a schema change, on the first [sqlite3_step()] call following any change 3513 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3514 ** ^The specific value of WHERE-clause [parameter] might influence the 3515 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3516 ** or [GLOB] operator or if the parameter is compared to an indexed column 3517 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3518 ** </li> 3519 ** </ol> 3520 */ 3521 SQLITE_API int sqlite3_prepare( 3522 sqlite3 *db, /* Database handle */ 3523 const char *zSql, /* SQL statement, UTF-8 encoded */ 3524 int nByte, /* Maximum length of zSql in bytes. */ 3525 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3526 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3527 ); 3528 SQLITE_API int sqlite3_prepare_v2( 3529 sqlite3 *db, /* Database handle */ 3530 const char *zSql, /* SQL statement, UTF-8 encoded */ 3531 int nByte, /* Maximum length of zSql in bytes. */ 3532 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3533 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3534 ); 3535 SQLITE_API int sqlite3_prepare16( 3536 sqlite3 *db, /* Database handle */ 3537 const void *zSql, /* SQL statement, UTF-16 encoded */ 3538 int nByte, /* Maximum length of zSql in bytes. */ 3539 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3540 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3541 ); 3542 SQLITE_API int sqlite3_prepare16_v2( 3543 sqlite3 *db, /* Database handle */ 3544 const void *zSql, /* SQL statement, UTF-16 encoded */ 3545 int nByte, /* Maximum length of zSql in bytes. */ 3546 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3547 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3548 ); 3549 3550 /* 3551 ** CAPI3REF: Retrieving Statement SQL 3552 ** METHOD: sqlite3_stmt 3553 ** 3554 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3555 ** SQL text used to create [prepared statement] P if P was 3556 ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3557 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3558 ** string containing the SQL text of prepared statement P with 3559 ** [bound parameters] expanded. 3560 ** 3561 ** ^(For example, if a prepared statement is created using the SQL 3562 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3563 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3564 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3565 ** will return "SELECT 2345,NULL".)^ 3566 ** 3567 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3568 ** is available to hold the result, or if the result would exceed the 3569 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3570 ** 3571 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3572 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3573 ** option causes sqlite3_expanded_sql() to always return NULL. 3574 ** 3575 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3576 ** automatically freed when the prepared statement is finalized. 3577 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3578 ** is obtained from [sqlite3_malloc()] and must be free by the application 3579 ** by passing it to [sqlite3_free()]. 3580 */ 3581 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3582 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3583 3584 /* 3585 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3586 ** METHOD: sqlite3_stmt 3587 ** 3588 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3589 ** and only if the [prepared statement] X makes no direct changes to 3590 ** the content of the database file. 3591 ** 3592 ** Note that [application-defined SQL functions] or 3593 ** [virtual tables] might change the database indirectly as a side effect. 3594 ** ^(For example, if an application defines a function "eval()" that 3595 ** calls [sqlite3_exec()], then the following SQL statement would 3596 ** change the database file through side-effects: 3597 ** 3598 ** <blockquote><pre> 3599 ** SELECT eval('DELETE FROM t1') FROM t2; 3600 ** </pre></blockquote> 3601 ** 3602 ** But because the [SELECT] statement does not change the database file 3603 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3604 ** 3605 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3606 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3607 ** since the statements themselves do not actually modify the database but 3608 ** rather they control the timing of when other statements modify the 3609 ** database. ^The [ATTACH] and [DETACH] statements also cause 3610 ** sqlite3_stmt_readonly() to return true since, while those statements 3611 ** change the configuration of a database connection, they do not make 3612 ** changes to the content of the database files on disk. 3613 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3614 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3615 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3616 ** sqlite3_stmt_readonly() returns false for those commands. 3617 */ 3618 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3619 3620 /* 3621 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3622 ** METHOD: sqlite3_stmt 3623 ** 3624 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3625 ** [prepared statement] S has been stepped at least once using 3626 ** [sqlite3_step(S)] but has neither run to completion (returned 3627 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3628 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3629 ** interface returns false if S is a NULL pointer. If S is not a 3630 ** NULL pointer and is not a pointer to a valid [prepared statement] 3631 ** object, then the behavior is undefined and probably undesirable. 3632 ** 3633 ** This interface can be used in combination [sqlite3_next_stmt()] 3634 ** to locate all prepared statements associated with a database 3635 ** connection that are in need of being reset. This can be used, 3636 ** for example, in diagnostic routines to search for prepared 3637 ** statements that are holding a transaction open. 3638 */ 3639 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3640 3641 /* 3642 ** CAPI3REF: Dynamically Typed Value Object 3643 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3644 ** 3645 ** SQLite uses the sqlite3_value object to represent all values 3646 ** that can be stored in a database table. SQLite uses dynamic typing 3647 ** for the values it stores. ^Values stored in sqlite3_value objects 3648 ** can be integers, floating point values, strings, BLOBs, or NULL. 3649 ** 3650 ** An sqlite3_value object may be either "protected" or "unprotected". 3651 ** Some interfaces require a protected sqlite3_value. Other interfaces 3652 ** will accept either a protected or an unprotected sqlite3_value. 3653 ** Every interface that accepts sqlite3_value arguments specifies 3654 ** whether or not it requires a protected sqlite3_value. The 3655 ** [sqlite3_value_dup()] interface can be used to construct a new 3656 ** protected sqlite3_value from an unprotected sqlite3_value. 3657 ** 3658 ** The terms "protected" and "unprotected" refer to whether or not 3659 ** a mutex is held. An internal mutex is held for a protected 3660 ** sqlite3_value object but no mutex is held for an unprotected 3661 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3662 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3663 ** or if SQLite is run in one of reduced mutex modes 3664 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3665 ** then there is no distinction between protected and unprotected 3666 ** sqlite3_value objects and they can be used interchangeably. However, 3667 ** for maximum code portability it is recommended that applications 3668 ** still make the distinction between protected and unprotected 3669 ** sqlite3_value objects even when not strictly required. 3670 ** 3671 ** ^The sqlite3_value objects that are passed as parameters into the 3672 ** implementation of [application-defined SQL functions] are protected. 3673 ** ^The sqlite3_value object returned by 3674 ** [sqlite3_column_value()] is unprotected. 3675 ** Unprotected sqlite3_value objects may only be used with 3676 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3677 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3678 ** interfaces require protected sqlite3_value objects. 3679 */ 3680 typedef struct Mem sqlite3_value; 3681 3682 /* 3683 ** CAPI3REF: SQL Function Context Object 3684 ** 3685 ** The context in which an SQL function executes is stored in an 3686 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3687 ** is always first parameter to [application-defined SQL functions]. 3688 ** The application-defined SQL function implementation will pass this 3689 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3690 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3691 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3692 ** and/or [sqlite3_set_auxdata()]. 3693 */ 3694 typedef struct sqlite3_context sqlite3_context; 3695 3696 /* 3697 ** CAPI3REF: Binding Values To Prepared Statements 3698 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3699 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3700 ** METHOD: sqlite3_stmt 3701 ** 3702 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3703 ** literals may be replaced by a [parameter] that matches one of following 3704 ** templates: 3705 ** 3706 ** <ul> 3707 ** <li> ? 3708 ** <li> ?NNN 3709 ** <li> :VVV 3710 ** <li> @VVV 3711 ** <li> $VVV 3712 ** </ul> 3713 ** 3714 ** In the templates above, NNN represents an integer literal, 3715 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3716 ** parameters (also called "host parameter names" or "SQL parameters") 3717 ** can be set using the sqlite3_bind_*() routines defined here. 3718 ** 3719 ** ^The first argument to the sqlite3_bind_*() routines is always 3720 ** a pointer to the [sqlite3_stmt] object returned from 3721 ** [sqlite3_prepare_v2()] or its variants. 3722 ** 3723 ** ^The second argument is the index of the SQL parameter to be set. 3724 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3725 ** SQL parameter is used more than once, second and subsequent 3726 ** occurrences have the same index as the first occurrence. 3727 ** ^The index for named parameters can be looked up using the 3728 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3729 ** for "?NNN" parameters is the value of NNN. 3730 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3731 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3732 ** 3733 ** ^The third argument is the value to bind to the parameter. 3734 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3735 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3736 ** is ignored and the end result is the same as sqlite3_bind_null(). 3737 ** 3738 ** ^(In those routines that have a fourth argument, its value is the 3739 ** number of bytes in the parameter. To be clear: the value is the 3740 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3741 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3742 ** is negative, then the length of the string is 3743 ** the number of bytes up to the first zero terminator. 3744 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3745 ** the behavior is undefined. 3746 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3747 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3748 ** that parameter must be the byte offset 3749 ** where the NUL terminator would occur assuming the string were NUL 3750 ** terminated. If any NUL characters occur at byte offsets less than 3751 ** the value of the fourth parameter then the resulting string value will 3752 ** contain embedded NULs. The result of expressions involving strings 3753 ** with embedded NULs is undefined. 3754 ** 3755 ** ^The fifth argument to the BLOB and string binding interfaces 3756 ** is a destructor used to dispose of the BLOB or 3757 ** string after SQLite has finished with it. ^The destructor is called 3758 ** to dispose of the BLOB or string even if the call to bind API fails. 3759 ** ^If the fifth argument is 3760 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3761 ** information is in static, unmanaged space and does not need to be freed. 3762 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3763 ** SQLite makes its own private copy of the data immediately, before 3764 ** the sqlite3_bind_*() routine returns. 3765 ** 3766 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3767 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3768 ** to specify the encoding of the text in the third parameter. If 3769 ** the sixth argument to sqlite3_bind_text64() is not one of the 3770 ** allowed values shown above, or if the text encoding is different 3771 ** from the encoding specified by the sixth parameter, then the behavior 3772 ** is undefined. 3773 ** 3774 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3775 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3776 ** (just an integer to hold its size) while it is being processed. 3777 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3778 ** content is later written using 3779 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3780 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3781 ** 3782 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3783 ** for the [prepared statement] or with a prepared statement for which 3784 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3785 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3786 ** routine is passed a [prepared statement] that has been finalized, the 3787 ** result is undefined and probably harmful. 3788 ** 3789 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3790 ** ^Unbound parameters are interpreted as NULL. 3791 ** 3792 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3793 ** [error code] if anything goes wrong. 3794 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3795 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3796 ** [SQLITE_MAX_LENGTH]. 3797 ** ^[SQLITE_RANGE] is returned if the parameter 3798 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3799 ** 3800 ** See also: [sqlite3_bind_parameter_count()], 3801 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3802 */ 3803 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3804 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3805 void(*)(void*)); 3806 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3807 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3808 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3809 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3810 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3811 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3812 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3813 void(*)(void*), unsigned char encoding); 3814 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3815 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3816 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3817 3818 /* 3819 ** CAPI3REF: Number Of SQL Parameters 3820 ** METHOD: sqlite3_stmt 3821 ** 3822 ** ^This routine can be used to find the number of [SQL parameters] 3823 ** in a [prepared statement]. SQL parameters are tokens of the 3824 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3825 ** placeholders for values that are [sqlite3_bind_blob | bound] 3826 ** to the parameters at a later time. 3827 ** 3828 ** ^(This routine actually returns the index of the largest (rightmost) 3829 ** parameter. For all forms except ?NNN, this will correspond to the 3830 ** number of unique parameters. If parameters of the ?NNN form are used, 3831 ** there may be gaps in the list.)^ 3832 ** 3833 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3834 ** [sqlite3_bind_parameter_name()], and 3835 ** [sqlite3_bind_parameter_index()]. 3836 */ 3837 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3838 3839 /* 3840 ** CAPI3REF: Name Of A Host Parameter 3841 ** METHOD: sqlite3_stmt 3842 ** 3843 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3844 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3845 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3846 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3847 ** respectively. 3848 ** In other words, the initial ":" or "$" or "@" or "?" 3849 ** is included as part of the name.)^ 3850 ** ^Parameters of the form "?" without a following integer have no name 3851 ** and are referred to as "nameless" or "anonymous parameters". 3852 ** 3853 ** ^The first host parameter has an index of 1, not 0. 3854 ** 3855 ** ^If the value N is out of range or if the N-th parameter is 3856 ** nameless, then NULL is returned. ^The returned string is 3857 ** always in UTF-8 encoding even if the named parameter was 3858 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3859 ** [sqlite3_prepare16_v2()]. 3860 ** 3861 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3862 ** [sqlite3_bind_parameter_count()], and 3863 ** [sqlite3_bind_parameter_index()]. 3864 */ 3865 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3866 3867 /* 3868 ** CAPI3REF: Index Of A Parameter With A Given Name 3869 ** METHOD: sqlite3_stmt 3870 ** 3871 ** ^Return the index of an SQL parameter given its name. ^The 3872 ** index value returned is suitable for use as the second 3873 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3874 ** is returned if no matching parameter is found. ^The parameter 3875 ** name must be given in UTF-8 even if the original statement 3876 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3877 ** 3878 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3879 ** [sqlite3_bind_parameter_count()], and 3880 ** [sqlite3_bind_parameter_name()]. 3881 */ 3882 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3883 3884 /* 3885 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3886 ** METHOD: sqlite3_stmt 3887 ** 3888 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3889 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3890 ** ^Use this routine to reset all host parameters to NULL. 3891 */ 3892 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3893 3894 /* 3895 ** CAPI3REF: Number Of Columns In A Result Set 3896 ** METHOD: sqlite3_stmt 3897 ** 3898 ** ^Return the number of columns in the result set returned by the 3899 ** [prepared statement]. ^If this routine returns 0, that means the 3900 ** [prepared statement] returns no data (for example an [UPDATE]). 3901 ** ^However, just because this routine returns a positive number does not 3902 ** mean that one or more rows of data will be returned. ^A SELECT statement 3903 ** will always have a positive sqlite3_column_count() but depending on the 3904 ** WHERE clause constraints and the table content, it might return no rows. 3905 ** 3906 ** See also: [sqlite3_data_count()] 3907 */ 3908 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3909 3910 /* 3911 ** CAPI3REF: Column Names In A Result Set 3912 ** METHOD: sqlite3_stmt 3913 ** 3914 ** ^These routines return the name assigned to a particular column 3915 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3916 ** interface returns a pointer to a zero-terminated UTF-8 string 3917 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3918 ** UTF-16 string. ^The first parameter is the [prepared statement] 3919 ** that implements the [SELECT] statement. ^The second parameter is the 3920 ** column number. ^The leftmost column is number 0. 3921 ** 3922 ** ^The returned string pointer is valid until either the [prepared statement] 3923 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3924 ** reprepared by the first call to [sqlite3_step()] for a particular run 3925 ** or until the next call to 3926 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3927 ** 3928 ** ^If sqlite3_malloc() fails during the processing of either routine 3929 ** (for example during a conversion from UTF-8 to UTF-16) then a 3930 ** NULL pointer is returned. 3931 ** 3932 ** ^The name of a result column is the value of the "AS" clause for 3933 ** that column, if there is an AS clause. If there is no AS clause 3934 ** then the name of the column is unspecified and may change from 3935 ** one release of SQLite to the next. 3936 */ 3937 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3938 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3939 3940 /* 3941 ** CAPI3REF: Source Of Data In A Query Result 3942 ** METHOD: sqlite3_stmt 3943 ** 3944 ** ^These routines provide a means to determine the database, table, and 3945 ** table column that is the origin of a particular result column in 3946 ** [SELECT] statement. 3947 ** ^The name of the database or table or column can be returned as 3948 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3949 ** the database name, the _table_ routines return the table name, and 3950 ** the origin_ routines return the column name. 3951 ** ^The returned string is valid until the [prepared statement] is destroyed 3952 ** using [sqlite3_finalize()] or until the statement is automatically 3953 ** reprepared by the first call to [sqlite3_step()] for a particular run 3954 ** or until the same information is requested 3955 ** again in a different encoding. 3956 ** 3957 ** ^The names returned are the original un-aliased names of the 3958 ** database, table, and column. 3959 ** 3960 ** ^The first argument to these interfaces is a [prepared statement]. 3961 ** ^These functions return information about the Nth result column returned by 3962 ** the statement, where N is the second function argument. 3963 ** ^The left-most column is column 0 for these routines. 3964 ** 3965 ** ^If the Nth column returned by the statement is an expression or 3966 ** subquery and is not a column value, then all of these functions return 3967 ** NULL. ^These routine might also return NULL if a memory allocation error 3968 ** occurs. ^Otherwise, they return the name of the attached database, table, 3969 ** or column that query result column was extracted from. 3970 ** 3971 ** ^As with all other SQLite APIs, those whose names end with "16" return 3972 ** UTF-16 encoded strings and the other functions return UTF-8. 3973 ** 3974 ** ^These APIs are only available if the library was compiled with the 3975 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3976 ** 3977 ** If two or more threads call one or more of these routines against the same 3978 ** prepared statement and column at the same time then the results are 3979 ** undefined. 3980 ** 3981 ** If two or more threads call one or more 3982 ** [sqlite3_column_database_name | column metadata interfaces] 3983 ** for the same [prepared statement] and result column 3984 ** at the same time then the results are undefined. 3985 */ 3986 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3987 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3988 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3989 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3990 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3991 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3992 3993 /* 3994 ** CAPI3REF: Declared Datatype Of A Query Result 3995 ** METHOD: sqlite3_stmt 3996 ** 3997 ** ^(The first parameter is a [prepared statement]. 3998 ** If this statement is a [SELECT] statement and the Nth column of the 3999 ** returned result set of that [SELECT] is a table column (not an 4000 ** expression or subquery) then the declared type of the table 4001 ** column is returned.)^ ^If the Nth column of the result set is an 4002 ** expression or subquery, then a NULL pointer is returned. 4003 ** ^The returned string is always UTF-8 encoded. 4004 ** 4005 ** ^(For example, given the database schema: 4006 ** 4007 ** CREATE TABLE t1(c1 VARIANT); 4008 ** 4009 ** and the following statement to be compiled: 4010 ** 4011 ** SELECT c1 + 1, c1 FROM t1; 4012 ** 4013 ** this routine would return the string "VARIANT" for the second result 4014 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4015 ** 4016 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4017 ** is declared to contain a particular type does not mean that the 4018 ** data stored in that column is of the declared type. SQLite is 4019 ** strongly typed, but the typing is dynamic not static. ^Type 4020 ** is associated with individual values, not with the containers 4021 ** used to hold those values. 4022 */ 4023 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4024 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4025 4026 /* 4027 ** CAPI3REF: Evaluate An SQL Statement 4028 ** METHOD: sqlite3_stmt 4029 ** 4030 ** After a [prepared statement] has been prepared using either 4031 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 4032 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4033 ** must be called one or more times to evaluate the statement. 4034 ** 4035 ** The details of the behavior of the sqlite3_step() interface depend 4036 ** on whether the statement was prepared using the newer "v2" interface 4037 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 4038 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4039 ** new "v2" interface is recommended for new applications but the legacy 4040 ** interface will continue to be supported. 4041 ** 4042 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4043 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4044 ** ^With the "v2" interface, any of the other [result codes] or 4045 ** [extended result codes] might be returned as well. 4046 ** 4047 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4048 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4049 ** or occurs outside of an explicit transaction, then you can retry the 4050 ** statement. If the statement is not a [COMMIT] and occurs within an 4051 ** explicit transaction then you should rollback the transaction before 4052 ** continuing. 4053 ** 4054 ** ^[SQLITE_DONE] means that the statement has finished executing 4055 ** successfully. sqlite3_step() should not be called again on this virtual 4056 ** machine without first calling [sqlite3_reset()] to reset the virtual 4057 ** machine back to its initial state. 4058 ** 4059 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4060 ** is returned each time a new row of data is ready for processing by the 4061 ** caller. The values may be accessed using the [column access functions]. 4062 ** sqlite3_step() is called again to retrieve the next row of data. 4063 ** 4064 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4065 ** violation) has occurred. sqlite3_step() should not be called again on 4066 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4067 ** ^With the legacy interface, a more specific error code (for example, 4068 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4069 ** can be obtained by calling [sqlite3_reset()] on the 4070 ** [prepared statement]. ^In the "v2" interface, 4071 ** the more specific error code is returned directly by sqlite3_step(). 4072 ** 4073 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4074 ** Perhaps it was called on a [prepared statement] that has 4075 ** already been [sqlite3_finalize | finalized] or on one that had 4076 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4077 ** be the case that the same database connection is being used by two or 4078 ** more threads at the same moment in time. 4079 ** 4080 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4081 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4082 ** other than [SQLITE_ROW] before any subsequent invocation of 4083 ** sqlite3_step(). Failure to reset the prepared statement using 4084 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4085 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4086 ** sqlite3_step() began 4087 ** calling [sqlite3_reset()] automatically in this circumstance rather 4088 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4089 ** break because any application that ever receives an SQLITE_MISUSE error 4090 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4091 ** can be used to restore the legacy behavior. 4092 ** 4093 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4094 ** API always returns a generic error code, [SQLITE_ERROR], following any 4095 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4096 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4097 ** specific [error codes] that better describes the error. 4098 ** We admit that this is a goofy design. The problem has been fixed 4099 ** with the "v2" interface. If you prepare all of your SQL statements 4100 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4101 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4102 ** then the more specific [error codes] are returned directly 4103 ** by sqlite3_step(). The use of the "v2" interface is recommended. 4104 */ 4105 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4106 4107 /* 4108 ** CAPI3REF: Number of columns in a result set 4109 ** METHOD: sqlite3_stmt 4110 ** 4111 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4112 ** current row of the result set of [prepared statement] P. 4113 ** ^If prepared statement P does not have results ready to return 4114 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4115 ** interfaces) then sqlite3_data_count(P) returns 0. 4116 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4117 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4118 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4119 ** will return non-zero if previous call to [sqlite3_step](P) returned 4120 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4121 ** where it always returns zero since each step of that multi-step 4122 ** pragma returns 0 columns of data. 4123 ** 4124 ** See also: [sqlite3_column_count()] 4125 */ 4126 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4127 4128 /* 4129 ** CAPI3REF: Fundamental Datatypes 4130 ** KEYWORDS: SQLITE_TEXT 4131 ** 4132 ** ^(Every value in SQLite has one of five fundamental datatypes: 4133 ** 4134 ** <ul> 4135 ** <li> 64-bit signed integer 4136 ** <li> 64-bit IEEE floating point number 4137 ** <li> string 4138 ** <li> BLOB 4139 ** <li> NULL 4140 ** </ul>)^ 4141 ** 4142 ** These constants are codes for each of those types. 4143 ** 4144 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4145 ** for a completely different meaning. Software that links against both 4146 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4147 ** SQLITE_TEXT. 4148 */ 4149 #define SQLITE_INTEGER 1 4150 #define SQLITE_FLOAT 2 4151 #define SQLITE_BLOB 4 4152 #define SQLITE_NULL 5 4153 #ifdef SQLITE_TEXT 4154 # undef SQLITE_TEXT 4155 #else 4156 # define SQLITE_TEXT 3 4157 #endif 4158 #define SQLITE3_TEXT 3 4159 4160 /* 4161 ** CAPI3REF: Result Values From A Query 4162 ** KEYWORDS: {column access functions} 4163 ** METHOD: sqlite3_stmt 4164 ** 4165 ** ^These routines return information about a single column of the current 4166 ** result row of a query. ^In every case the first argument is a pointer 4167 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4168 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4169 ** and the second argument is the index of the column for which information 4170 ** should be returned. ^The leftmost column of the result set has the index 0. 4171 ** ^The number of columns in the result can be determined using 4172 ** [sqlite3_column_count()]. 4173 ** 4174 ** If the SQL statement does not currently point to a valid row, or if the 4175 ** column index is out of range, the result is undefined. 4176 ** These routines may only be called when the most recent call to 4177 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4178 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4179 ** If any of these routines are called after [sqlite3_reset()] or 4180 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4181 ** something other than [SQLITE_ROW], the results are undefined. 4182 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4183 ** are called from a different thread while any of these routines 4184 ** are pending, then the results are undefined. 4185 ** 4186 ** ^The sqlite3_column_type() routine returns the 4187 ** [SQLITE_INTEGER | datatype code] for the initial data type 4188 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4189 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4190 ** returned by sqlite3_column_type() is only meaningful if no type 4191 ** conversions have occurred as described below. After a type conversion, 4192 ** the value returned by sqlite3_column_type() is undefined. Future 4193 ** versions of SQLite may change the behavior of sqlite3_column_type() 4194 ** following a type conversion. 4195 ** 4196 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4197 ** routine returns the number of bytes in that BLOB or string. 4198 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4199 ** the string to UTF-8 and then returns the number of bytes. 4200 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4201 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4202 ** the number of bytes in that string. 4203 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4204 ** 4205 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4206 ** routine returns the number of bytes in that BLOB or string. 4207 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4208 ** the string to UTF-16 and then returns the number of bytes. 4209 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4210 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4211 ** the number of bytes in that string. 4212 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4213 ** 4214 ** ^The values returned by [sqlite3_column_bytes()] and 4215 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4216 ** of the string. ^For clarity: the values returned by 4217 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4218 ** bytes in the string, not the number of characters. 4219 ** 4220 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4221 ** even empty strings, are always zero-terminated. ^The return 4222 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4223 ** 4224 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4225 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4226 ** an unprotected sqlite3_value object may only be used safely with 4227 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4228 ** If the [unprotected sqlite3_value] object returned by 4229 ** [sqlite3_column_value()] is used in any other way, including calls 4230 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4231 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4232 ** 4233 ** These routines attempt to convert the value where appropriate. ^For 4234 ** example, if the internal representation is FLOAT and a text result 4235 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4236 ** conversion automatically. ^(The following table details the conversions 4237 ** that are applied: 4238 ** 4239 ** <blockquote> 4240 ** <table border="1"> 4241 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4242 ** 4243 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4244 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4245 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4246 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4247 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4248 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4249 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4250 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4251 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4252 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4253 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4254 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4255 ** <tr><td> TEXT <td> BLOB <td> No change 4256 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4257 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4258 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4259 ** </table> 4260 ** </blockquote>)^ 4261 ** 4262 ** Note that when type conversions occur, pointers returned by prior 4263 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4264 ** sqlite3_column_text16() may be invalidated. 4265 ** Type conversions and pointer invalidations might occur 4266 ** in the following cases: 4267 ** 4268 ** <ul> 4269 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4270 ** sqlite3_column_text16() is called. A zero-terminator might 4271 ** need to be added to the string.</li> 4272 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4273 ** sqlite3_column_text16() is called. The content must be converted 4274 ** to UTF-16.</li> 4275 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4276 ** sqlite3_column_text() is called. The content must be converted 4277 ** to UTF-8.</li> 4278 ** </ul> 4279 ** 4280 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4281 ** not invalidate a prior pointer, though of course the content of the buffer 4282 ** that the prior pointer references will have been modified. Other kinds 4283 ** of conversion are done in place when it is possible, but sometimes they 4284 ** are not possible and in those cases prior pointers are invalidated. 4285 ** 4286 ** The safest policy is to invoke these routines 4287 ** in one of the following ways: 4288 ** 4289 ** <ul> 4290 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4291 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4292 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4293 ** </ul> 4294 ** 4295 ** In other words, you should call sqlite3_column_text(), 4296 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4297 ** into the desired format, then invoke sqlite3_column_bytes() or 4298 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4299 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4300 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4301 ** with calls to sqlite3_column_bytes(). 4302 ** 4303 ** ^The pointers returned are valid until a type conversion occurs as 4304 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4305 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4306 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4307 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4308 ** [sqlite3_free()]. 4309 ** 4310 ** ^(If a memory allocation error occurs during the evaluation of any 4311 ** of these routines, a default value is returned. The default value 4312 ** is either the integer 0, the floating point number 0.0, or a NULL 4313 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4314 ** [SQLITE_NOMEM].)^ 4315 */ 4316 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4317 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4318 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4319 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4320 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4321 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4322 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4323 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4324 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4325 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4326 4327 /* 4328 ** CAPI3REF: Destroy A Prepared Statement Object 4329 ** DESTRUCTOR: sqlite3_stmt 4330 ** 4331 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4332 ** ^If the most recent evaluation of the statement encountered no errors 4333 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4334 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4335 ** sqlite3_finalize(S) returns the appropriate [error code] or 4336 ** [extended error code]. 4337 ** 4338 ** ^The sqlite3_finalize(S) routine can be called at any point during 4339 ** the life cycle of [prepared statement] S: 4340 ** before statement S is ever evaluated, after 4341 ** one or more calls to [sqlite3_reset()], or after any call 4342 ** to [sqlite3_step()] regardless of whether or not the statement has 4343 ** completed execution. 4344 ** 4345 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4346 ** 4347 ** The application must finalize every [prepared statement] in order to avoid 4348 ** resource leaks. It is a grievous error for the application to try to use 4349 ** a prepared statement after it has been finalized. Any use of a prepared 4350 ** statement after it has been finalized can result in undefined and 4351 ** undesirable behavior such as segfaults and heap corruption. 4352 */ 4353 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4354 4355 /* 4356 ** CAPI3REF: Reset A Prepared Statement Object 4357 ** METHOD: sqlite3_stmt 4358 ** 4359 ** The sqlite3_reset() function is called to reset a [prepared statement] 4360 ** object back to its initial state, ready to be re-executed. 4361 ** ^Any SQL statement variables that had values bound to them using 4362 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4363 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4364 ** 4365 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4366 ** back to the beginning of its program. 4367 ** 4368 ** ^If the most recent call to [sqlite3_step(S)] for the 4369 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4370 ** or if [sqlite3_step(S)] has never before been called on S, 4371 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4372 ** 4373 ** ^If the most recent call to [sqlite3_step(S)] for the 4374 ** [prepared statement] S indicated an error, then 4375 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4376 ** 4377 ** ^The [sqlite3_reset(S)] interface does not change the values 4378 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4379 */ 4380 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4381 4382 /* 4383 ** CAPI3REF: Create Or Redefine SQL Functions 4384 ** KEYWORDS: {function creation routines} 4385 ** KEYWORDS: {application-defined SQL function} 4386 ** KEYWORDS: {application-defined SQL functions} 4387 ** METHOD: sqlite3 4388 ** 4389 ** ^These functions (collectively known as "function creation routines") 4390 ** are used to add SQL functions or aggregates or to redefine the behavior 4391 ** of existing SQL functions or aggregates. The only differences between 4392 ** these routines are the text encoding expected for 4393 ** the second parameter (the name of the function being created) 4394 ** and the presence or absence of a destructor callback for 4395 ** the application data pointer. 4396 ** 4397 ** ^The first parameter is the [database connection] to which the SQL 4398 ** function is to be added. ^If an application uses more than one database 4399 ** connection then application-defined SQL functions must be added 4400 ** to each database connection separately. 4401 ** 4402 ** ^The second parameter is the name of the SQL function to be created or 4403 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4404 ** representation, exclusive of the zero-terminator. ^Note that the name 4405 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4406 ** ^Any attempt to create a function with a longer name 4407 ** will result in [SQLITE_MISUSE] being returned. 4408 ** 4409 ** ^The third parameter (nArg) 4410 ** is the number of arguments that the SQL function or 4411 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4412 ** aggregate may take any number of arguments between 0 and the limit 4413 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4414 ** parameter is less than -1 or greater than 127 then the behavior is 4415 ** undefined. 4416 ** 4417 ** ^The fourth parameter, eTextRep, specifies what 4418 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4419 ** its parameters. The application should set this parameter to 4420 ** [SQLITE_UTF16LE] if the function implementation invokes 4421 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4422 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4423 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4424 ** otherwise. ^The same SQL function may be registered multiple times using 4425 ** different preferred text encodings, with different implementations for 4426 ** each encoding. 4427 ** ^When multiple implementations of the same function are available, SQLite 4428 ** will pick the one that involves the least amount of data conversion. 4429 ** 4430 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4431 ** to signal that the function will always return the same result given 4432 ** the same inputs within a single SQL statement. Most SQL functions are 4433 ** deterministic. The built-in [random()] SQL function is an example of a 4434 ** function that is not deterministic. The SQLite query planner is able to 4435 ** perform additional optimizations on deterministic functions, so use 4436 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4437 ** 4438 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4439 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4440 ** 4441 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4442 ** pointers to C-language functions that implement the SQL function or 4443 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4444 ** callback only; NULL pointers must be passed as the xStep and xFinal 4445 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4446 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4447 ** SQL function or aggregate, pass NULL pointers for all three function 4448 ** callbacks. 4449 ** 4450 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4451 ** then it is destructor for the application data pointer. 4452 ** The destructor is invoked when the function is deleted, either by being 4453 ** overloaded or when the database connection closes.)^ 4454 ** ^The destructor is also invoked if the call to 4455 ** sqlite3_create_function_v2() fails. 4456 ** ^When the destructor callback of the tenth parameter is invoked, it 4457 ** is passed a single argument which is a copy of the application data 4458 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4459 ** 4460 ** ^It is permitted to register multiple implementations of the same 4461 ** functions with the same name but with either differing numbers of 4462 ** arguments or differing preferred text encodings. ^SQLite will use 4463 ** the implementation that most closely matches the way in which the 4464 ** SQL function is used. ^A function implementation with a non-negative 4465 ** nArg parameter is a better match than a function implementation with 4466 ** a negative nArg. ^A function where the preferred text encoding 4467 ** matches the database encoding is a better 4468 ** match than a function where the encoding is different. 4469 ** ^A function where the encoding difference is between UTF16le and UTF16be 4470 ** is a closer match than a function where the encoding difference is 4471 ** between UTF8 and UTF16. 4472 ** 4473 ** ^Built-in functions may be overloaded by new application-defined functions. 4474 ** 4475 ** ^An application-defined function is permitted to call other 4476 ** SQLite interfaces. However, such calls must not 4477 ** close the database connection nor finalize or reset the prepared 4478 ** statement in which the function is running. 4479 */ 4480 SQLITE_API int sqlite3_create_function( 4481 sqlite3 *db, 4482 const char *zFunctionName, 4483 int nArg, 4484 int eTextRep, 4485 void *pApp, 4486 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4487 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4488 void (*xFinal)(sqlite3_context*) 4489 ); 4490 SQLITE_API int sqlite3_create_function16( 4491 sqlite3 *db, 4492 const void *zFunctionName, 4493 int nArg, 4494 int eTextRep, 4495 void *pApp, 4496 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4497 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4498 void (*xFinal)(sqlite3_context*) 4499 ); 4500 SQLITE_API int sqlite3_create_function_v2( 4501 sqlite3 *db, 4502 const char *zFunctionName, 4503 int nArg, 4504 int eTextRep, 4505 void *pApp, 4506 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4507 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4508 void (*xFinal)(sqlite3_context*), 4509 void(*xDestroy)(void*) 4510 ); 4511 4512 /* 4513 ** CAPI3REF: Text Encodings 4514 ** 4515 ** These constant define integer codes that represent the various 4516 ** text encodings supported by SQLite. 4517 */ 4518 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4519 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4520 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4521 #define SQLITE_UTF16 4 /* Use native byte order */ 4522 #define SQLITE_ANY 5 /* Deprecated */ 4523 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4524 4525 /* 4526 ** CAPI3REF: Function Flags 4527 ** 4528 ** These constants may be ORed together with the 4529 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4530 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4531 ** [sqlite3_create_function_v2()]. 4532 */ 4533 #define SQLITE_DETERMINISTIC 0x800 4534 4535 /* 4536 ** CAPI3REF: Deprecated Functions 4537 ** DEPRECATED 4538 ** 4539 ** These functions are [deprecated]. In order to maintain 4540 ** backwards compatibility with older code, these functions continue 4541 ** to be supported. However, new applications should avoid 4542 ** the use of these functions. To encourage programmers to avoid 4543 ** these functions, we will not explain what they do. 4544 */ 4545 #ifndef SQLITE_OMIT_DEPRECATED 4546 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4547 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4548 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4549 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4550 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4551 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4552 void*,sqlite3_int64); 4553 #endif 4554 4555 /* 4556 ** CAPI3REF: Obtaining SQL Values 4557 ** METHOD: sqlite3_value 4558 ** 4559 ** The C-language implementation of SQL functions and aggregates uses 4560 ** this set of interface routines to access the parameter values on 4561 ** the function or aggregate. 4562 ** 4563 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4564 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4565 ** define callbacks that implement the SQL functions and aggregates. 4566 ** The 3rd parameter to these callbacks is an array of pointers to 4567 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4568 ** each parameter to the SQL function. These routines are used to 4569 ** extract values from the [sqlite3_value] objects. 4570 ** 4571 ** These routines work only with [protected sqlite3_value] objects. 4572 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4573 ** object results in undefined behavior. 4574 ** 4575 ** ^These routines work just like the corresponding [column access functions] 4576 ** except that these routines take a single [protected sqlite3_value] object 4577 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4578 ** 4579 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4580 ** in the native byte-order of the host machine. ^The 4581 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4582 ** extract UTF-16 strings as big-endian and little-endian respectively. 4583 ** 4584 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4585 ** numeric affinity to the value. This means that an attempt is 4586 ** made to convert the value to an integer or floating point. If 4587 ** such a conversion is possible without loss of information (in other 4588 ** words, if the value is a string that looks like a number) 4589 ** then the conversion is performed. Otherwise no conversion occurs. 4590 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4591 ** 4592 ** Please pay particular attention to the fact that the pointer returned 4593 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4594 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4595 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4596 ** or [sqlite3_value_text16()]. 4597 ** 4598 ** These routines must be called from the same thread as 4599 ** the SQL function that supplied the [sqlite3_value*] parameters. 4600 */ 4601 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4602 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4603 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4604 SQLITE_API double sqlite3_value_double(sqlite3_value*); 4605 SQLITE_API int sqlite3_value_int(sqlite3_value*); 4606 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4607 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4608 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4609 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4610 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4611 SQLITE_API int sqlite3_value_type(sqlite3_value*); 4612 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4613 4614 /* 4615 ** CAPI3REF: Finding The Subtype Of SQL Values 4616 ** METHOD: sqlite3_value 4617 ** 4618 ** The sqlite3_value_subtype(V) function returns the subtype for 4619 ** an [application-defined SQL function] argument V. The subtype 4620 ** information can be used to pass a limited amount of context from 4621 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4622 ** routine to set the subtype for the return value of an SQL function. 4623 ** 4624 ** SQLite makes no use of subtype itself. It merely passes the subtype 4625 ** from the result of one [application-defined SQL function] into the 4626 ** input of another. 4627 */ 4628 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4629 4630 /* 4631 ** CAPI3REF: Copy And Free SQL Values 4632 ** METHOD: sqlite3_value 4633 ** 4634 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4635 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4636 ** is a [protected sqlite3_value] object even if the input is not. 4637 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4638 ** memory allocation fails. 4639 ** 4640 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4641 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4642 ** then sqlite3_value_free(V) is a harmless no-op. 4643 */ 4644 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4645 SQLITE_API void sqlite3_value_free(sqlite3_value*); 4646 4647 /* 4648 ** CAPI3REF: Obtain Aggregate Function Context 4649 ** METHOD: sqlite3_context 4650 ** 4651 ** Implementations of aggregate SQL functions use this 4652 ** routine to allocate memory for storing their state. 4653 ** 4654 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4655 ** for a particular aggregate function, SQLite 4656 ** allocates N of memory, zeroes out that memory, and returns a pointer 4657 ** to the new memory. ^On second and subsequent calls to 4658 ** sqlite3_aggregate_context() for the same aggregate function instance, 4659 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4660 ** called once for each invocation of the xStep callback and then one 4661 ** last time when the xFinal callback is invoked. ^(When no rows match 4662 ** an aggregate query, the xStep() callback of the aggregate function 4663 ** implementation is never called and xFinal() is called exactly once. 4664 ** In those cases, sqlite3_aggregate_context() might be called for the 4665 ** first time from within xFinal().)^ 4666 ** 4667 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4668 ** when first called if N is less than or equal to zero or if a memory 4669 ** allocate error occurs. 4670 ** 4671 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4672 ** determined by the N parameter on first successful call. Changing the 4673 ** value of N in subsequent call to sqlite3_aggregate_context() within 4674 ** the same aggregate function instance will not resize the memory 4675 ** allocation.)^ Within the xFinal callback, it is customary to set 4676 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4677 ** pointless memory allocations occur. 4678 ** 4679 ** ^SQLite automatically frees the memory allocated by 4680 ** sqlite3_aggregate_context() when the aggregate query concludes. 4681 ** 4682 ** The first parameter must be a copy of the 4683 ** [sqlite3_context | SQL function context] that is the first parameter 4684 ** to the xStep or xFinal callback routine that implements the aggregate 4685 ** function. 4686 ** 4687 ** This routine must be called from the same thread in which 4688 ** the aggregate SQL function is running. 4689 */ 4690 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4691 4692 /* 4693 ** CAPI3REF: User Data For Functions 4694 ** METHOD: sqlite3_context 4695 ** 4696 ** ^The sqlite3_user_data() interface returns a copy of 4697 ** the pointer that was the pUserData parameter (the 5th parameter) 4698 ** of the [sqlite3_create_function()] 4699 ** and [sqlite3_create_function16()] routines that originally 4700 ** registered the application defined function. 4701 ** 4702 ** This routine must be called from the same thread in which 4703 ** the application-defined function is running. 4704 */ 4705 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4706 4707 /* 4708 ** CAPI3REF: Database Connection For Functions 4709 ** METHOD: sqlite3_context 4710 ** 4711 ** ^The sqlite3_context_db_handle() interface returns a copy of 4712 ** the pointer to the [database connection] (the 1st parameter) 4713 ** of the [sqlite3_create_function()] 4714 ** and [sqlite3_create_function16()] routines that originally 4715 ** registered the application defined function. 4716 */ 4717 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4718 4719 /* 4720 ** CAPI3REF: Function Auxiliary Data 4721 ** METHOD: sqlite3_context 4722 ** 4723 ** These functions may be used by (non-aggregate) SQL functions to 4724 ** associate metadata with argument values. If the same value is passed to 4725 ** multiple invocations of the same SQL function during query execution, under 4726 ** some circumstances the associated metadata may be preserved. An example 4727 ** of where this might be useful is in a regular-expression matching 4728 ** function. The compiled version of the regular expression can be stored as 4729 ** metadata associated with the pattern string. 4730 ** Then as long as the pattern string remains the same, 4731 ** the compiled regular expression can be reused on multiple 4732 ** invocations of the same function. 4733 ** 4734 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4735 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4736 ** value to the application-defined function. ^If there is no metadata 4737 ** associated with the function argument, this sqlite3_get_auxdata() interface 4738 ** returns a NULL pointer. 4739 ** 4740 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4741 ** argument of the application-defined function. ^Subsequent 4742 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4743 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4744 ** NULL if the metadata has been discarded. 4745 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4746 ** SQLite will invoke the destructor function X with parameter P exactly 4747 ** once, when the metadata is discarded. 4748 ** SQLite is free to discard the metadata at any time, including: <ul> 4749 ** <li> ^(when the corresponding function parameter changes)^, or 4750 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4751 ** SQL statement)^, or 4752 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4753 ** parameter)^, or 4754 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4755 ** allocation error occurs.)^ </ul> 4756 ** 4757 ** Note the last bullet in particular. The destructor X in 4758 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4759 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4760 ** should be called near the end of the function implementation and the 4761 ** function implementation should not make any use of P after 4762 ** sqlite3_set_auxdata() has been called. 4763 ** 4764 ** ^(In practice, metadata is preserved between function calls for 4765 ** function parameters that are compile-time constants, including literal 4766 ** values and [parameters] and expressions composed from the same.)^ 4767 ** 4768 ** These routines must be called from the same thread in which 4769 ** the SQL function is running. 4770 */ 4771 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4772 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4773 4774 4775 /* 4776 ** CAPI3REF: Constants Defining Special Destructor Behavior 4777 ** 4778 ** These are special values for the destructor that is passed in as the 4779 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4780 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4781 ** and will never change. It does not need to be destroyed. ^The 4782 ** SQLITE_TRANSIENT value means that the content will likely change in 4783 ** the near future and that SQLite should make its own private copy of 4784 ** the content before returning. 4785 ** 4786 ** The typedef is necessary to work around problems in certain 4787 ** C++ compilers. 4788 */ 4789 typedef void (*sqlite3_destructor_type)(void*); 4790 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4791 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4792 4793 /* 4794 ** CAPI3REF: Setting The Result Of An SQL Function 4795 ** METHOD: sqlite3_context 4796 ** 4797 ** These routines are used by the xFunc or xFinal callbacks that 4798 ** implement SQL functions and aggregates. See 4799 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4800 ** for additional information. 4801 ** 4802 ** These functions work very much like the [parameter binding] family of 4803 ** functions used to bind values to host parameters in prepared statements. 4804 ** Refer to the [SQL parameter] documentation for additional information. 4805 ** 4806 ** ^The sqlite3_result_blob() interface sets the result from 4807 ** an application-defined function to be the BLOB whose content is pointed 4808 ** to by the second parameter and which is N bytes long where N is the 4809 ** third parameter. 4810 ** 4811 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4812 ** interfaces set the result of the application-defined function to be 4813 ** a BLOB containing all zero bytes and N bytes in size. 4814 ** 4815 ** ^The sqlite3_result_double() interface sets the result from 4816 ** an application-defined function to be a floating point value specified 4817 ** by its 2nd argument. 4818 ** 4819 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4820 ** cause the implemented SQL function to throw an exception. 4821 ** ^SQLite uses the string pointed to by the 4822 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4823 ** as the text of an error message. ^SQLite interprets the error 4824 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4825 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4826 ** byte order. ^If the third parameter to sqlite3_result_error() 4827 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4828 ** message all text up through the first zero character. 4829 ** ^If the third parameter to sqlite3_result_error() or 4830 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4831 ** bytes (not characters) from the 2nd parameter as the error message. 4832 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4833 ** routines make a private copy of the error message text before 4834 ** they return. Hence, the calling function can deallocate or 4835 ** modify the text after they return without harm. 4836 ** ^The sqlite3_result_error_code() function changes the error code 4837 ** returned by SQLite as a result of an error in a function. ^By default, 4838 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4839 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4840 ** 4841 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4842 ** error indicating that a string or BLOB is too long to represent. 4843 ** 4844 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4845 ** error indicating that a memory allocation failed. 4846 ** 4847 ** ^The sqlite3_result_int() interface sets the return value 4848 ** of the application-defined function to be the 32-bit signed integer 4849 ** value given in the 2nd argument. 4850 ** ^The sqlite3_result_int64() interface sets the return value 4851 ** of the application-defined function to be the 64-bit signed integer 4852 ** value given in the 2nd argument. 4853 ** 4854 ** ^The sqlite3_result_null() interface sets the return value 4855 ** of the application-defined function to be NULL. 4856 ** 4857 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4858 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4859 ** set the return value of the application-defined function to be 4860 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4861 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4862 ** ^The sqlite3_result_text64() interface sets the return value of an 4863 ** application-defined function to be a text string in an encoding 4864 ** specified by the fifth (and last) parameter, which must be one 4865 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4866 ** ^SQLite takes the text result from the application from 4867 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4868 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4869 ** is negative, then SQLite takes result text from the 2nd parameter 4870 ** through the first zero character. 4871 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4872 ** is non-negative, then as many bytes (not characters) of the text 4873 ** pointed to by the 2nd parameter are taken as the application-defined 4874 ** function result. If the 3rd parameter is non-negative, then it 4875 ** must be the byte offset into the string where the NUL terminator would 4876 ** appear if the string where NUL terminated. If any NUL characters occur 4877 ** in the string at a byte offset that is less than the value of the 3rd 4878 ** parameter, then the resulting string will contain embedded NULs and the 4879 ** result of expressions operating on strings with embedded NULs is undefined. 4880 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4881 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4882 ** function as the destructor on the text or BLOB result when it has 4883 ** finished using that result. 4884 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4885 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4886 ** assumes that the text or BLOB result is in constant space and does not 4887 ** copy the content of the parameter nor call a destructor on the content 4888 ** when it has finished using that result. 4889 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4890 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4891 ** then SQLite makes a copy of the result into space obtained from 4892 ** from [sqlite3_malloc()] before it returns. 4893 ** 4894 ** ^The sqlite3_result_value() interface sets the result of 4895 ** the application-defined function to be a copy of the 4896 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4897 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4898 ** so that the [sqlite3_value] specified in the parameter may change or 4899 ** be deallocated after sqlite3_result_value() returns without harm. 4900 ** ^A [protected sqlite3_value] object may always be used where an 4901 ** [unprotected sqlite3_value] object is required, so either 4902 ** kind of [sqlite3_value] object can be used with this interface. 4903 ** 4904 ** If these routines are called from within the different thread 4905 ** than the one containing the application-defined function that received 4906 ** the [sqlite3_context] pointer, the results are undefined. 4907 */ 4908 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4909 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 4910 sqlite3_uint64,void(*)(void*)); 4911 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4912 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4913 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4914 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4915 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4916 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4917 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4918 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4919 SQLITE_API void sqlite3_result_null(sqlite3_context*); 4920 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4921 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4922 void(*)(void*), unsigned char encoding); 4923 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4924 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4925 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4926 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4927 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4928 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4929 4930 4931 /* 4932 ** CAPI3REF: Setting The Subtype Of An SQL Function 4933 ** METHOD: sqlite3_context 4934 ** 4935 ** The sqlite3_result_subtype(C,T) function causes the subtype of 4936 ** the result from the [application-defined SQL function] with 4937 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 4938 ** of the subtype T are preserved in current versions of SQLite; 4939 ** higher order bits are discarded. 4940 ** The number of subtype bytes preserved by SQLite might increase 4941 ** in future releases of SQLite. 4942 */ 4943 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 4944 4945 /* 4946 ** CAPI3REF: Define New Collating Sequences 4947 ** METHOD: sqlite3 4948 ** 4949 ** ^These functions add, remove, or modify a [collation] associated 4950 ** with the [database connection] specified as the first argument. 4951 ** 4952 ** ^The name of the collation is a UTF-8 string 4953 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4954 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4955 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4956 ** considered to be the same name. 4957 ** 4958 ** ^(The third argument (eTextRep) must be one of the constants: 4959 ** <ul> 4960 ** <li> [SQLITE_UTF8], 4961 ** <li> [SQLITE_UTF16LE], 4962 ** <li> [SQLITE_UTF16BE], 4963 ** <li> [SQLITE_UTF16], or 4964 ** <li> [SQLITE_UTF16_ALIGNED]. 4965 ** </ul>)^ 4966 ** ^The eTextRep argument determines the encoding of strings passed 4967 ** to the collating function callback, xCallback. 4968 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4969 ** force strings to be UTF16 with native byte order. 4970 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4971 ** on an even byte address. 4972 ** 4973 ** ^The fourth argument, pArg, is an application data pointer that is passed 4974 ** through as the first argument to the collating function callback. 4975 ** 4976 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4977 ** ^Multiple collating functions can be registered using the same name but 4978 ** with different eTextRep parameters and SQLite will use whichever 4979 ** function requires the least amount of data transformation. 4980 ** ^If the xCallback argument is NULL then the collating function is 4981 ** deleted. ^When all collating functions having the same name are deleted, 4982 ** that collation is no longer usable. 4983 ** 4984 ** ^The collating function callback is invoked with a copy of the pArg 4985 ** application data pointer and with two strings in the encoding specified 4986 ** by the eTextRep argument. The collating function must return an 4987 ** integer that is negative, zero, or positive 4988 ** if the first string is less than, equal to, or greater than the second, 4989 ** respectively. A collating function must always return the same answer 4990 ** given the same inputs. If two or more collating functions are registered 4991 ** to the same collation name (using different eTextRep values) then all 4992 ** must give an equivalent answer when invoked with equivalent strings. 4993 ** The collating function must obey the following properties for all 4994 ** strings A, B, and C: 4995 ** 4996 ** <ol> 4997 ** <li> If A==B then B==A. 4998 ** <li> If A==B and B==C then A==C. 4999 ** <li> If A<B THEN B>A. 5000 ** <li> If A<B and B<C then A<C. 5001 ** </ol> 5002 ** 5003 ** If a collating function fails any of the above constraints and that 5004 ** collating function is registered and used, then the behavior of SQLite 5005 ** is undefined. 5006 ** 5007 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5008 ** with the addition that the xDestroy callback is invoked on pArg when 5009 ** the collating function is deleted. 5010 ** ^Collating functions are deleted when they are overridden by later 5011 ** calls to the collation creation functions or when the 5012 ** [database connection] is closed using [sqlite3_close()]. 5013 ** 5014 ** ^The xDestroy callback is <u>not</u> called if the 5015 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5016 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5017 ** check the return code and dispose of the application data pointer 5018 ** themselves rather than expecting SQLite to deal with it for them. 5019 ** This is different from every other SQLite interface. The inconsistency 5020 ** is unfortunate but cannot be changed without breaking backwards 5021 ** compatibility. 5022 ** 5023 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5024 */ 5025 SQLITE_API int sqlite3_create_collation( 5026 sqlite3*, 5027 const char *zName, 5028 int eTextRep, 5029 void *pArg, 5030 int(*xCompare)(void*,int,const void*,int,const void*) 5031 ); 5032 SQLITE_API int sqlite3_create_collation_v2( 5033 sqlite3*, 5034 const char *zName, 5035 int eTextRep, 5036 void *pArg, 5037 int(*xCompare)(void*,int,const void*,int,const void*), 5038 void(*xDestroy)(void*) 5039 ); 5040 SQLITE_API int sqlite3_create_collation16( 5041 sqlite3*, 5042 const void *zName, 5043 int eTextRep, 5044 void *pArg, 5045 int(*xCompare)(void*,int,const void*,int,const void*) 5046 ); 5047 5048 /* 5049 ** CAPI3REF: Collation Needed Callbacks 5050 ** METHOD: sqlite3 5051 ** 5052 ** ^To avoid having to register all collation sequences before a database 5053 ** can be used, a single callback function may be registered with the 5054 ** [database connection] to be invoked whenever an undefined collation 5055 ** sequence is required. 5056 ** 5057 ** ^If the function is registered using the sqlite3_collation_needed() API, 5058 ** then it is passed the names of undefined collation sequences as strings 5059 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5060 ** the names are passed as UTF-16 in machine native byte order. 5061 ** ^A call to either function replaces the existing collation-needed callback. 5062 ** 5063 ** ^(When the callback is invoked, the first argument passed is a copy 5064 ** of the second argument to sqlite3_collation_needed() or 5065 ** sqlite3_collation_needed16(). The second argument is the database 5066 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5067 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5068 ** sequence function required. The fourth parameter is the name of the 5069 ** required collation sequence.)^ 5070 ** 5071 ** The callback function should register the desired collation using 5072 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5073 ** [sqlite3_create_collation_v2()]. 5074 */ 5075 SQLITE_API int sqlite3_collation_needed( 5076 sqlite3*, 5077 void*, 5078 void(*)(void*,sqlite3*,int eTextRep,const char*) 5079 ); 5080 SQLITE_API int sqlite3_collation_needed16( 5081 sqlite3*, 5082 void*, 5083 void(*)(void*,sqlite3*,int eTextRep,const void*) 5084 ); 5085 5086 #ifdef SQLITE_HAS_CODEC 5087 /* 5088 ** Specify the key for an encrypted database. This routine should be 5089 ** called right after sqlite3_open(). 5090 ** 5091 ** The code to implement this API is not available in the public release 5092 ** of SQLite. 5093 */ 5094 SQLITE_API int sqlite3_key( 5095 sqlite3 *db, /* Database to be rekeyed */ 5096 const void *pKey, int nKey /* The key */ 5097 ); 5098 SQLITE_API int sqlite3_key_v2( 5099 sqlite3 *db, /* Database to be rekeyed */ 5100 const char *zDbName, /* Name of the database */ 5101 const void *pKey, int nKey /* The key */ 5102 ); 5103 5104 /* 5105 ** Change the key on an open database. If the current database is not 5106 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5107 ** database is decrypted. 5108 ** 5109 ** The code to implement this API is not available in the public release 5110 ** of SQLite. 5111 */ 5112 SQLITE_API int sqlite3_rekey( 5113 sqlite3 *db, /* Database to be rekeyed */ 5114 const void *pKey, int nKey /* The new key */ 5115 ); 5116 SQLITE_API int sqlite3_rekey_v2( 5117 sqlite3 *db, /* Database to be rekeyed */ 5118 const char *zDbName, /* Name of the database */ 5119 const void *pKey, int nKey /* The new key */ 5120 ); 5121 5122 /* 5123 ** Specify the activation key for a SEE database. Unless 5124 ** activated, none of the SEE routines will work. 5125 */ 5126 SQLITE_API void sqlite3_activate_see( 5127 const char *zPassPhrase /* Activation phrase */ 5128 ); 5129 #endif 5130 5131 #ifdef SQLITE_ENABLE_CEROD 5132 /* 5133 ** Specify the activation key for a CEROD database. Unless 5134 ** activated, none of the CEROD routines will work. 5135 */ 5136 SQLITE_API void sqlite3_activate_cerod( 5137 const char *zPassPhrase /* Activation phrase */ 5138 ); 5139 #endif 5140 5141 /* 5142 ** CAPI3REF: Suspend Execution For A Short Time 5143 ** 5144 ** The sqlite3_sleep() function causes the current thread to suspend execution 5145 ** for at least a number of milliseconds specified in its parameter. 5146 ** 5147 ** If the operating system does not support sleep requests with 5148 ** millisecond time resolution, then the time will be rounded up to 5149 ** the nearest second. The number of milliseconds of sleep actually 5150 ** requested from the operating system is returned. 5151 ** 5152 ** ^SQLite implements this interface by calling the xSleep() 5153 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5154 ** of the default VFS is not implemented correctly, or not implemented at 5155 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5156 ** in the previous paragraphs. 5157 */ 5158 SQLITE_API int sqlite3_sleep(int); 5159 5160 /* 5161 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5162 ** 5163 ** ^(If this global variable is made to point to a string which is 5164 ** the name of a folder (a.k.a. directory), then all temporary files 5165 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5166 ** will be placed in that directory.)^ ^If this variable 5167 ** is a NULL pointer, then SQLite performs a search for an appropriate 5168 ** temporary file directory. 5169 ** 5170 ** Applications are strongly discouraged from using this global variable. 5171 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5172 ** But for all other platforms, it is highly recommended that applications 5173 ** neither read nor write this variable. This global variable is a relic 5174 ** that exists for backwards compatibility of legacy applications and should 5175 ** be avoided in new projects. 5176 ** 5177 ** It is not safe to read or modify this variable in more than one 5178 ** thread at a time. It is not safe to read or modify this variable 5179 ** if a [database connection] is being used at the same time in a separate 5180 ** thread. 5181 ** It is intended that this variable be set once 5182 ** as part of process initialization and before any SQLite interface 5183 ** routines have been called and that this variable remain unchanged 5184 ** thereafter. 5185 ** 5186 ** ^The [temp_store_directory pragma] may modify this variable and cause 5187 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5188 ** the [temp_store_directory pragma] always assumes that any string 5189 ** that this variable points to is held in memory obtained from 5190 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5191 ** using [sqlite3_free]. 5192 ** Hence, if this variable is modified directly, either it should be 5193 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5194 ** or else the use of the [temp_store_directory pragma] should be avoided. 5195 ** Except when requested by the [temp_store_directory pragma], SQLite 5196 ** does not free the memory that sqlite3_temp_directory points to. If 5197 ** the application wants that memory to be freed, it must do 5198 ** so itself, taking care to only do so after all [database connection] 5199 ** objects have been destroyed. 5200 ** 5201 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5202 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5203 ** features that require the use of temporary files may fail. Here is an 5204 ** example of how to do this using C++ with the Windows Runtime: 5205 ** 5206 ** <blockquote><pre> 5207 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5208 ** TemporaryFolder->Path->Data(); 5209 ** char zPathBuf[MAX_PATH + 1]; 5210 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5211 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5212 ** NULL, NULL); 5213 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5214 ** </pre></blockquote> 5215 */ 5216 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5217 5218 /* 5219 ** CAPI3REF: Name Of The Folder Holding Database Files 5220 ** 5221 ** ^(If this global variable is made to point to a string which is 5222 ** the name of a folder (a.k.a. directory), then all database files 5223 ** specified with a relative pathname and created or accessed by 5224 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5225 ** to be relative to that directory.)^ ^If this variable is a NULL 5226 ** pointer, then SQLite assumes that all database files specified 5227 ** with a relative pathname are relative to the current directory 5228 ** for the process. Only the windows VFS makes use of this global 5229 ** variable; it is ignored by the unix VFS. 5230 ** 5231 ** Changing the value of this variable while a database connection is 5232 ** open can result in a corrupt database. 5233 ** 5234 ** It is not safe to read or modify this variable in more than one 5235 ** thread at a time. It is not safe to read or modify this variable 5236 ** if a [database connection] is being used at the same time in a separate 5237 ** thread. 5238 ** It is intended that this variable be set once 5239 ** as part of process initialization and before any SQLite interface 5240 ** routines have been called and that this variable remain unchanged 5241 ** thereafter. 5242 ** 5243 ** ^The [data_store_directory pragma] may modify this variable and cause 5244 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5245 ** the [data_store_directory pragma] always assumes that any string 5246 ** that this variable points to is held in memory obtained from 5247 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5248 ** using [sqlite3_free]. 5249 ** Hence, if this variable is modified directly, either it should be 5250 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5251 ** or else the use of the [data_store_directory pragma] should be avoided. 5252 */ 5253 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5254 5255 /* 5256 ** CAPI3REF: Test For Auto-Commit Mode 5257 ** KEYWORDS: {autocommit mode} 5258 ** METHOD: sqlite3 5259 ** 5260 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5261 ** zero if the given database connection is or is not in autocommit mode, 5262 ** respectively. ^Autocommit mode is on by default. 5263 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5264 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5265 ** 5266 ** If certain kinds of errors occur on a statement within a multi-statement 5267 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5268 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5269 ** transaction might be rolled back automatically. The only way to 5270 ** find out whether SQLite automatically rolled back the transaction after 5271 ** an error is to use this function. 5272 ** 5273 ** If another thread changes the autocommit status of the database 5274 ** connection while this routine is running, then the return value 5275 ** is undefined. 5276 */ 5277 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5278 5279 /* 5280 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5281 ** METHOD: sqlite3_stmt 5282 ** 5283 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5284 ** to which a [prepared statement] belongs. ^The [database connection] 5285 ** returned by sqlite3_db_handle is the same [database connection] 5286 ** that was the first argument 5287 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5288 ** create the statement in the first place. 5289 */ 5290 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5291 5292 /* 5293 ** CAPI3REF: Return The Filename For A Database Connection 5294 ** METHOD: sqlite3 5295 ** 5296 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5297 ** associated with database N of connection D. ^The main database file 5298 ** has the name "main". If there is no attached database N on the database 5299 ** connection D, or if database N is a temporary or in-memory database, then 5300 ** a NULL pointer is returned. 5301 ** 5302 ** ^The filename returned by this function is the output of the 5303 ** xFullPathname method of the [VFS]. ^In other words, the filename 5304 ** will be an absolute pathname, even if the filename used 5305 ** to open the database originally was a URI or relative pathname. 5306 */ 5307 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5308 5309 /* 5310 ** CAPI3REF: Determine if a database is read-only 5311 ** METHOD: sqlite3 5312 ** 5313 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5314 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5315 ** the name of a database on connection D. 5316 */ 5317 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5318 5319 /* 5320 ** CAPI3REF: Find the next prepared statement 5321 ** METHOD: sqlite3 5322 ** 5323 ** ^This interface returns a pointer to the next [prepared statement] after 5324 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5325 ** then this interface returns a pointer to the first prepared statement 5326 ** associated with the database connection pDb. ^If no prepared statement 5327 ** satisfies the conditions of this routine, it returns NULL. 5328 ** 5329 ** The [database connection] pointer D in a call to 5330 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5331 ** connection and in particular must not be a NULL pointer. 5332 */ 5333 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5334 5335 /* 5336 ** CAPI3REF: Commit And Rollback Notification Callbacks 5337 ** METHOD: sqlite3 5338 ** 5339 ** ^The sqlite3_commit_hook() interface registers a callback 5340 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5341 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5342 ** for the same database connection is overridden. 5343 ** ^The sqlite3_rollback_hook() interface registers a callback 5344 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5345 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5346 ** for the same database connection is overridden. 5347 ** ^The pArg argument is passed through to the callback. 5348 ** ^If the callback on a commit hook function returns non-zero, 5349 ** then the commit is converted into a rollback. 5350 ** 5351 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5352 ** return the P argument from the previous call of the same function 5353 ** on the same [database connection] D, or NULL for 5354 ** the first call for each function on D. 5355 ** 5356 ** The commit and rollback hook callbacks are not reentrant. 5357 ** The callback implementation must not do anything that will modify 5358 ** the database connection that invoked the callback. Any actions 5359 ** to modify the database connection must be deferred until after the 5360 ** completion of the [sqlite3_step()] call that triggered the commit 5361 ** or rollback hook in the first place. 5362 ** Note that running any other SQL statements, including SELECT statements, 5363 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5364 ** the database connections for the meaning of "modify" in this paragraph. 5365 ** 5366 ** ^Registering a NULL function disables the callback. 5367 ** 5368 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5369 ** operation is allowed to continue normally. ^If the commit hook 5370 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5371 ** ^The rollback hook is invoked on a rollback that results from a commit 5372 ** hook returning non-zero, just as it would be with any other rollback. 5373 ** 5374 ** ^For the purposes of this API, a transaction is said to have been 5375 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5376 ** an error or constraint causes an implicit rollback to occur. 5377 ** ^The rollback callback is not invoked if a transaction is 5378 ** automatically rolled back because the database connection is closed. 5379 ** 5380 ** See also the [sqlite3_update_hook()] interface. 5381 */ 5382 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5383 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5384 5385 /* 5386 ** CAPI3REF: Data Change Notification Callbacks 5387 ** METHOD: sqlite3 5388 ** 5389 ** ^The sqlite3_update_hook() interface registers a callback function 5390 ** with the [database connection] identified by the first argument 5391 ** to be invoked whenever a row is updated, inserted or deleted in 5392 ** a [rowid table]. 5393 ** ^Any callback set by a previous call to this function 5394 ** for the same database connection is overridden. 5395 ** 5396 ** ^The second argument is a pointer to the function to invoke when a 5397 ** row is updated, inserted or deleted in a rowid table. 5398 ** ^The first argument to the callback is a copy of the third argument 5399 ** to sqlite3_update_hook(). 5400 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5401 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5402 ** to be invoked. 5403 ** ^The third and fourth arguments to the callback contain pointers to the 5404 ** database and table name containing the affected row. 5405 ** ^The final callback parameter is the [rowid] of the row. 5406 ** ^In the case of an update, this is the [rowid] after the update takes place. 5407 ** 5408 ** ^(The update hook is not invoked when internal system tables are 5409 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5410 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5411 ** 5412 ** ^In the current implementation, the update hook 5413 ** is not invoked when duplication rows are deleted because of an 5414 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5415 ** invoked when rows are deleted using the [truncate optimization]. 5416 ** The exceptions defined in this paragraph might change in a future 5417 ** release of SQLite. 5418 ** 5419 ** The update hook implementation must not do anything that will modify 5420 ** the database connection that invoked the update hook. Any actions 5421 ** to modify the database connection must be deferred until after the 5422 ** completion of the [sqlite3_step()] call that triggered the update hook. 5423 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5424 ** database connections for the meaning of "modify" in this paragraph. 5425 ** 5426 ** ^The sqlite3_update_hook(D,C,P) function 5427 ** returns the P argument from the previous call 5428 ** on the same [database connection] D, or NULL for 5429 ** the first call on D. 5430 ** 5431 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5432 ** and [sqlite3_preupdate_hook()] interfaces. 5433 */ 5434 SQLITE_API void *sqlite3_update_hook( 5435 sqlite3*, 5436 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5437 void* 5438 ); 5439 5440 /* 5441 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5442 ** 5443 ** ^(This routine enables or disables the sharing of the database cache 5444 ** and schema data structures between [database connection | connections] 5445 ** to the same database. Sharing is enabled if the argument is true 5446 ** and disabled if the argument is false.)^ 5447 ** 5448 ** ^Cache sharing is enabled and disabled for an entire process. 5449 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5450 ** In prior versions of SQLite, 5451 ** sharing was enabled or disabled for each thread separately. 5452 ** 5453 ** ^(The cache sharing mode set by this interface effects all subsequent 5454 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5455 ** Existing database connections continue use the sharing mode 5456 ** that was in effect at the time they were opened.)^ 5457 ** 5458 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5459 ** successfully. An [error code] is returned otherwise.)^ 5460 ** 5461 ** ^Shared cache is disabled by default. But this might change in 5462 ** future releases of SQLite. Applications that care about shared 5463 ** cache setting should set it explicitly. 5464 ** 5465 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5466 ** and will always return SQLITE_MISUSE. On those systems, 5467 ** shared cache mode should be enabled per-database connection via 5468 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5469 ** 5470 ** This interface is threadsafe on processors where writing a 5471 ** 32-bit integer is atomic. 5472 ** 5473 ** See Also: [SQLite Shared-Cache Mode] 5474 */ 5475 SQLITE_API int sqlite3_enable_shared_cache(int); 5476 5477 /* 5478 ** CAPI3REF: Attempt To Free Heap Memory 5479 ** 5480 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5481 ** of heap memory by deallocating non-essential memory allocations 5482 ** held by the database library. Memory used to cache database 5483 ** pages to improve performance is an example of non-essential memory. 5484 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5485 ** which might be more or less than the amount requested. 5486 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5487 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5488 ** 5489 ** See also: [sqlite3_db_release_memory()] 5490 */ 5491 SQLITE_API int sqlite3_release_memory(int); 5492 5493 /* 5494 ** CAPI3REF: Free Memory Used By A Database Connection 5495 ** METHOD: sqlite3 5496 ** 5497 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5498 ** memory as possible from database connection D. Unlike the 5499 ** [sqlite3_release_memory()] interface, this interface is in effect even 5500 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5501 ** omitted. 5502 ** 5503 ** See also: [sqlite3_release_memory()] 5504 */ 5505 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5506 5507 /* 5508 ** CAPI3REF: Impose A Limit On Heap Size 5509 ** 5510 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5511 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5512 ** ^SQLite strives to keep heap memory utilization below the soft heap 5513 ** limit by reducing the number of pages held in the page cache 5514 ** as heap memory usages approaches the limit. 5515 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5516 ** below the limit, it will exceed the limit rather than generate 5517 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5518 ** is advisory only. 5519 ** 5520 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5521 ** the soft heap limit prior to the call, or negative in the case of an 5522 ** error. ^If the argument N is negative 5523 ** then no change is made to the soft heap limit. Hence, the current 5524 ** size of the soft heap limit can be determined by invoking 5525 ** sqlite3_soft_heap_limit64() with a negative argument. 5526 ** 5527 ** ^If the argument N is zero then the soft heap limit is disabled. 5528 ** 5529 ** ^(The soft heap limit is not enforced in the current implementation 5530 ** if one or more of following conditions are true: 5531 ** 5532 ** <ul> 5533 ** <li> The soft heap limit is set to zero. 5534 ** <li> Memory accounting is disabled using a combination of the 5535 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5536 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5537 ** <li> An alternative page cache implementation is specified using 5538 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5539 ** <li> The page cache allocates from its own memory pool supplied 5540 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5541 ** from the heap. 5542 ** </ul>)^ 5543 ** 5544 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5545 ** the soft heap limit is enforced 5546 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5547 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5548 ** the soft heap limit is enforced on every memory allocation. Without 5549 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5550 ** when memory is allocated by the page cache. Testing suggests that because 5551 ** the page cache is the predominate memory user in SQLite, most 5552 ** applications will achieve adequate soft heap limit enforcement without 5553 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5554 ** 5555 ** The circumstances under which SQLite will enforce the soft heap limit may 5556 ** changes in future releases of SQLite. 5557 */ 5558 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5559 5560 /* 5561 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5562 ** DEPRECATED 5563 ** 5564 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5565 ** interface. This routine is provided for historical compatibility 5566 ** only. All new applications should use the 5567 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5568 */ 5569 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5570 5571 5572 /* 5573 ** CAPI3REF: Extract Metadata About A Column Of A Table 5574 ** METHOD: sqlite3 5575 ** 5576 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5577 ** information about column C of table T in database D 5578 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5579 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5580 ** the final five arguments with appropriate values if the specified 5581 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5582 ** SQLITE_ERROR and if the specified column does not exist. 5583 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5584 ** NULL pointer, then this routine simply checks for the existence of the 5585 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5586 ** does not. 5587 ** 5588 ** ^The column is identified by the second, third and fourth parameters to 5589 ** this function. ^(The second parameter is either the name of the database 5590 ** (i.e. "main", "temp", or an attached database) containing the specified 5591 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5592 ** for the table using the same algorithm used by the database engine to 5593 ** resolve unqualified table references. 5594 ** 5595 ** ^The third and fourth parameters to this function are the table and column 5596 ** name of the desired column, respectively. 5597 ** 5598 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5599 ** and subsequent parameters to this function. ^Any of these arguments may be 5600 ** NULL, in which case the corresponding element of metadata is omitted. 5601 ** 5602 ** ^(<blockquote> 5603 ** <table border="1"> 5604 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5605 ** 5606 ** <tr><td> 5th <td> const char* <td> Data type 5607 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5608 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5609 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5610 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5611 ** </table> 5612 ** </blockquote>)^ 5613 ** 5614 ** ^The memory pointed to by the character pointers returned for the 5615 ** declaration type and collation sequence is valid until the next 5616 ** call to any SQLite API function. 5617 ** 5618 ** ^If the specified table is actually a view, an [error code] is returned. 5619 ** 5620 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5621 ** is not a [WITHOUT ROWID] table and an 5622 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5623 ** parameters are set for the explicitly declared column. ^(If there is no 5624 ** [INTEGER PRIMARY KEY] column, then the outputs 5625 ** for the [rowid] are set as follows: 5626 ** 5627 ** <pre> 5628 ** data type: "INTEGER" 5629 ** collation sequence: "BINARY" 5630 ** not null: 0 5631 ** primary key: 1 5632 ** auto increment: 0 5633 ** </pre>)^ 5634 ** 5635 ** ^This function causes all database schemas to be read from disk and 5636 ** parsed, if that has not already been done, and returns an error if 5637 ** any errors are encountered while loading the schema. 5638 */ 5639 SQLITE_API int sqlite3_table_column_metadata( 5640 sqlite3 *db, /* Connection handle */ 5641 const char *zDbName, /* Database name or NULL */ 5642 const char *zTableName, /* Table name */ 5643 const char *zColumnName, /* Column name */ 5644 char const **pzDataType, /* OUTPUT: Declared data type */ 5645 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5646 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5647 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5648 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5649 ); 5650 5651 /* 5652 ** CAPI3REF: Load An Extension 5653 ** METHOD: sqlite3 5654 ** 5655 ** ^This interface loads an SQLite extension library from the named file. 5656 ** 5657 ** ^The sqlite3_load_extension() interface attempts to load an 5658 ** [SQLite extension] library contained in the file zFile. If 5659 ** the file cannot be loaded directly, attempts are made to load 5660 ** with various operating-system specific extensions added. 5661 ** So for example, if "samplelib" cannot be loaded, then names like 5662 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5663 ** be tried also. 5664 ** 5665 ** ^The entry point is zProc. 5666 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5667 ** entry point name on its own. It first tries "sqlite3_extension_init". 5668 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5669 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5670 ** characters in the filename from the last "/" to the first following 5671 ** "." and omitting any initial "lib".)^ 5672 ** ^The sqlite3_load_extension() interface returns 5673 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5674 ** ^If an error occurs and pzErrMsg is not 0, then the 5675 ** [sqlite3_load_extension()] interface shall attempt to 5676 ** fill *pzErrMsg with error message text stored in memory 5677 ** obtained from [sqlite3_malloc()]. The calling function 5678 ** should free this memory by calling [sqlite3_free()]. 5679 ** 5680 ** ^Extension loading must be enabled using 5681 ** [sqlite3_enable_load_extension()] or 5682 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5683 ** prior to calling this API, 5684 ** otherwise an error will be returned. 5685 ** 5686 ** <b>Security warning:</b> It is recommended that the 5687 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5688 ** interface. The use of the [sqlite3_enable_load_extension()] interface 5689 ** should be avoided. This will keep the SQL function [load_extension()] 5690 ** disabled and prevent SQL injections from giving attackers 5691 ** access to extension loading capabilities. 5692 ** 5693 ** See also the [load_extension() SQL function]. 5694 */ 5695 SQLITE_API int sqlite3_load_extension( 5696 sqlite3 *db, /* Load the extension into this database connection */ 5697 const char *zFile, /* Name of the shared library containing extension */ 5698 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5699 char **pzErrMsg /* Put error message here if not 0 */ 5700 ); 5701 5702 /* 5703 ** CAPI3REF: Enable Or Disable Extension Loading 5704 ** METHOD: sqlite3 5705 ** 5706 ** ^So as not to open security holes in older applications that are 5707 ** unprepared to deal with [extension loading], and as a means of disabling 5708 ** [extension loading] while evaluating user-entered SQL, the following API 5709 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5710 ** 5711 ** ^Extension loading is off by default. 5712 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5713 ** to turn extension loading on and call it with onoff==0 to turn 5714 ** it back off again. 5715 ** 5716 ** ^This interface enables or disables both the C-API 5717 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5718 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5719 ** to enable or disable only the C-API.)^ 5720 ** 5721 ** <b>Security warning:</b> It is recommended that extension loading 5722 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5723 ** rather than this interface, so the [load_extension()] SQL function 5724 ** remains disabled. This will prevent SQL injections from giving attackers 5725 ** access to extension loading capabilities. 5726 */ 5727 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5728 5729 /* 5730 ** CAPI3REF: Automatically Load Statically Linked Extensions 5731 ** 5732 ** ^This interface causes the xEntryPoint() function to be invoked for 5733 ** each new [database connection] that is created. The idea here is that 5734 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5735 ** that is to be automatically loaded into all new database connections. 5736 ** 5737 ** ^(Even though the function prototype shows that xEntryPoint() takes 5738 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5739 ** arguments and expects an integer result as if the signature of the 5740 ** entry point where as follows: 5741 ** 5742 ** <blockquote><pre> 5743 ** int xEntryPoint( 5744 ** sqlite3 *db, 5745 ** const char **pzErrMsg, 5746 ** const struct sqlite3_api_routines *pThunk 5747 ** ); 5748 ** </pre></blockquote>)^ 5749 ** 5750 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5751 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5752 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5753 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5754 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5755 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5756 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5757 ** 5758 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5759 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5760 ** will be called more than once for each database connection that is opened. 5761 ** 5762 ** See also: [sqlite3_reset_auto_extension()] 5763 ** and [sqlite3_cancel_auto_extension()] 5764 */ 5765 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 5766 5767 /* 5768 ** CAPI3REF: Cancel Automatic Extension Loading 5769 ** 5770 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5771 ** initialization routine X that was registered using a prior call to 5772 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5773 ** routine returns 1 if initialization routine X was successfully 5774 ** unregistered and it returns 0 if X was not on the list of initialization 5775 ** routines. 5776 */ 5777 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5778 5779 /* 5780 ** CAPI3REF: Reset Automatic Extension Loading 5781 ** 5782 ** ^This interface disables all automatic extensions previously 5783 ** registered using [sqlite3_auto_extension()]. 5784 */ 5785 SQLITE_API void sqlite3_reset_auto_extension(void); 5786 5787 /* 5788 ** The interface to the virtual-table mechanism is currently considered 5789 ** to be experimental. The interface might change in incompatible ways. 5790 ** If this is a problem for you, do not use the interface at this time. 5791 ** 5792 ** When the virtual-table mechanism stabilizes, we will declare the 5793 ** interface fixed, support it indefinitely, and remove this comment. 5794 */ 5795 5796 /* 5797 ** Structures used by the virtual table interface 5798 */ 5799 typedef struct sqlite3_vtab sqlite3_vtab; 5800 typedef struct sqlite3_index_info sqlite3_index_info; 5801 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5802 typedef struct sqlite3_module sqlite3_module; 5803 5804 /* 5805 ** CAPI3REF: Virtual Table Object 5806 ** KEYWORDS: sqlite3_module {virtual table module} 5807 ** 5808 ** This structure, sometimes called a "virtual table module", 5809 ** defines the implementation of a [virtual tables]. 5810 ** This structure consists mostly of methods for the module. 5811 ** 5812 ** ^A virtual table module is created by filling in a persistent 5813 ** instance of this structure and passing a pointer to that instance 5814 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5815 ** ^The registration remains valid until it is replaced by a different 5816 ** module or until the [database connection] closes. The content 5817 ** of this structure must not change while it is registered with 5818 ** any database connection. 5819 */ 5820 struct sqlite3_module { 5821 int iVersion; 5822 int (*xCreate)(sqlite3*, void *pAux, 5823 int argc, const char *const*argv, 5824 sqlite3_vtab **ppVTab, char**); 5825 int (*xConnect)(sqlite3*, void *pAux, 5826 int argc, const char *const*argv, 5827 sqlite3_vtab **ppVTab, char**); 5828 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5829 int (*xDisconnect)(sqlite3_vtab *pVTab); 5830 int (*xDestroy)(sqlite3_vtab *pVTab); 5831 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5832 int (*xClose)(sqlite3_vtab_cursor*); 5833 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5834 int argc, sqlite3_value **argv); 5835 int (*xNext)(sqlite3_vtab_cursor*); 5836 int (*xEof)(sqlite3_vtab_cursor*); 5837 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5838 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5839 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5840 int (*xBegin)(sqlite3_vtab *pVTab); 5841 int (*xSync)(sqlite3_vtab *pVTab); 5842 int (*xCommit)(sqlite3_vtab *pVTab); 5843 int (*xRollback)(sqlite3_vtab *pVTab); 5844 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5845 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5846 void **ppArg); 5847 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5848 /* The methods above are in version 1 of the sqlite_module object. Those 5849 ** below are for version 2 and greater. */ 5850 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5851 int (*xRelease)(sqlite3_vtab *pVTab, int); 5852 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5853 }; 5854 5855 /* 5856 ** CAPI3REF: Virtual Table Indexing Information 5857 ** KEYWORDS: sqlite3_index_info 5858 ** 5859 ** The sqlite3_index_info structure and its substructures is used as part 5860 ** of the [virtual table] interface to 5861 ** pass information into and receive the reply from the [xBestIndex] 5862 ** method of a [virtual table module]. The fields under **Inputs** are the 5863 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5864 ** results into the **Outputs** fields. 5865 ** 5866 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5867 ** 5868 ** <blockquote>column OP expr</blockquote> 5869 ** 5870 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5871 ** stored in aConstraint[].op using one of the 5872 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5873 ** ^(The index of the column is stored in 5874 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5875 ** expr on the right-hand side can be evaluated (and thus the constraint 5876 ** is usable) and false if it cannot.)^ 5877 ** 5878 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5879 ** and makes other simplifications to the WHERE clause in an attempt to 5880 ** get as many WHERE clause terms into the form shown above as possible. 5881 ** ^The aConstraint[] array only reports WHERE clause terms that are 5882 ** relevant to the particular virtual table being queried. 5883 ** 5884 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5885 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5886 ** 5887 ** The colUsed field indicates which columns of the virtual table may be 5888 ** required by the current scan. Virtual table columns are numbered from 5889 ** zero in the order in which they appear within the CREATE TABLE statement 5890 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5891 ** the corresponding bit is set within the colUsed mask if the column may be 5892 ** required by SQLite. If the table has at least 64 columns and any column 5893 ** to the right of the first 63 is required, then bit 63 of colUsed is also 5894 ** set. In other words, column iCol may be required if the expression 5895 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5896 ** non-zero. 5897 ** 5898 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5899 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5900 ** the right-hand side of the corresponding aConstraint[] is evaluated 5901 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5902 ** is true, then the constraint is assumed to be fully handled by the 5903 ** virtual table and is not checked again by SQLite.)^ 5904 ** 5905 ** ^The idxNum and idxPtr values are recorded and passed into the 5906 ** [xFilter] method. 5907 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5908 ** needToFreeIdxPtr is true. 5909 ** 5910 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5911 ** the correct order to satisfy the ORDER BY clause so that no separate 5912 ** sorting step is required. 5913 ** 5914 ** ^The estimatedCost value is an estimate of the cost of a particular 5915 ** strategy. A cost of N indicates that the cost of the strategy is similar 5916 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5917 ** indicates that the expense of the operation is similar to that of a 5918 ** binary search on a unique indexed field of an SQLite table with N rows. 5919 ** 5920 ** ^The estimatedRows value is an estimate of the number of rows that 5921 ** will be returned by the strategy. 5922 ** 5923 ** The xBestIndex method may optionally populate the idxFlags field with a 5924 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5925 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5926 ** assumes that the strategy may visit at most one row. 5927 ** 5928 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5929 ** SQLite also assumes that if a call to the xUpdate() method is made as 5930 ** part of the same statement to delete or update a virtual table row and the 5931 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5932 ** any database changes. In other words, if the xUpdate() returns 5933 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5934 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5935 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5936 ** the xUpdate method are automatically rolled back by SQLite. 5937 ** 5938 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5939 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 5940 ** If a virtual table extension is 5941 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5942 ** to read or write the estimatedRows field are undefined (but are likely 5943 ** to included crashing the application). The estimatedRows field should 5944 ** therefore only be used if [sqlite3_libversion_number()] returns a 5945 ** value greater than or equal to 3008002. Similarly, the idxFlags field 5946 ** was added for [version 3.9.0] ([dateof:3.9.0]). 5947 ** It may therefore only be used if 5948 ** sqlite3_libversion_number() returns a value greater than or equal to 5949 ** 3009000. 5950 */ 5951 struct sqlite3_index_info { 5952 /* Inputs */ 5953 int nConstraint; /* Number of entries in aConstraint */ 5954 struct sqlite3_index_constraint { 5955 int iColumn; /* Column constrained. -1 for ROWID */ 5956 unsigned char op; /* Constraint operator */ 5957 unsigned char usable; /* True if this constraint is usable */ 5958 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5959 } *aConstraint; /* Table of WHERE clause constraints */ 5960 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5961 struct sqlite3_index_orderby { 5962 int iColumn; /* Column number */ 5963 unsigned char desc; /* True for DESC. False for ASC. */ 5964 } *aOrderBy; /* The ORDER BY clause */ 5965 /* Outputs */ 5966 struct sqlite3_index_constraint_usage { 5967 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5968 unsigned char omit; /* Do not code a test for this constraint */ 5969 } *aConstraintUsage; 5970 int idxNum; /* Number used to identify the index */ 5971 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5972 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5973 int orderByConsumed; /* True if output is already ordered */ 5974 double estimatedCost; /* Estimated cost of using this index */ 5975 /* Fields below are only available in SQLite 3.8.2 and later */ 5976 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5977 /* Fields below are only available in SQLite 3.9.0 and later */ 5978 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5979 /* Fields below are only available in SQLite 3.10.0 and later */ 5980 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5981 }; 5982 5983 /* 5984 ** CAPI3REF: Virtual Table Scan Flags 5985 */ 5986 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5987 5988 /* 5989 ** CAPI3REF: Virtual Table Constraint Operator Codes 5990 ** 5991 ** These macros defined the allowed values for the 5992 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5993 ** an operator that is part of a constraint term in the wHERE clause of 5994 ** a query that uses a [virtual table]. 5995 */ 5996 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5997 #define SQLITE_INDEX_CONSTRAINT_GT 4 5998 #define SQLITE_INDEX_CONSTRAINT_LE 8 5999 #define SQLITE_INDEX_CONSTRAINT_LT 16 6000 #define SQLITE_INDEX_CONSTRAINT_GE 32 6001 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6002 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6003 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6004 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6005 6006 /* 6007 ** CAPI3REF: Register A Virtual Table Implementation 6008 ** METHOD: sqlite3 6009 ** 6010 ** ^These routines are used to register a new [virtual table module] name. 6011 ** ^Module names must be registered before 6012 ** creating a new [virtual table] using the module and before using a 6013 ** preexisting [virtual table] for the module. 6014 ** 6015 ** ^The module name is registered on the [database connection] specified 6016 ** by the first parameter. ^The name of the module is given by the 6017 ** second parameter. ^The third parameter is a pointer to 6018 ** the implementation of the [virtual table module]. ^The fourth 6019 ** parameter is an arbitrary client data pointer that is passed through 6020 ** into the [xCreate] and [xConnect] methods of the virtual table module 6021 ** when a new virtual table is be being created or reinitialized. 6022 ** 6023 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6024 ** is a pointer to a destructor for the pClientData. ^SQLite will 6025 ** invoke the destructor function (if it is not NULL) when SQLite 6026 ** no longer needs the pClientData pointer. ^The destructor will also 6027 ** be invoked if the call to sqlite3_create_module_v2() fails. 6028 ** ^The sqlite3_create_module() 6029 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6030 ** destructor. 6031 */ 6032 SQLITE_API int sqlite3_create_module( 6033 sqlite3 *db, /* SQLite connection to register module with */ 6034 const char *zName, /* Name of the module */ 6035 const sqlite3_module *p, /* Methods for the module */ 6036 void *pClientData /* Client data for xCreate/xConnect */ 6037 ); 6038 SQLITE_API int sqlite3_create_module_v2( 6039 sqlite3 *db, /* SQLite connection to register module with */ 6040 const char *zName, /* Name of the module */ 6041 const sqlite3_module *p, /* Methods for the module */ 6042 void *pClientData, /* Client data for xCreate/xConnect */ 6043 void(*xDestroy)(void*) /* Module destructor function */ 6044 ); 6045 6046 /* 6047 ** CAPI3REF: Virtual Table Instance Object 6048 ** KEYWORDS: sqlite3_vtab 6049 ** 6050 ** Every [virtual table module] implementation uses a subclass 6051 ** of this object to describe a particular instance 6052 ** of the [virtual table]. Each subclass will 6053 ** be tailored to the specific needs of the module implementation. 6054 ** The purpose of this superclass is to define certain fields that are 6055 ** common to all module implementations. 6056 ** 6057 ** ^Virtual tables methods can set an error message by assigning a 6058 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6059 ** take care that any prior string is freed by a call to [sqlite3_free()] 6060 ** prior to assigning a new string to zErrMsg. ^After the error message 6061 ** is delivered up to the client application, the string will be automatically 6062 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6063 */ 6064 struct sqlite3_vtab { 6065 const sqlite3_module *pModule; /* The module for this virtual table */ 6066 int nRef; /* Number of open cursors */ 6067 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6068 /* Virtual table implementations will typically add additional fields */ 6069 }; 6070 6071 /* 6072 ** CAPI3REF: Virtual Table Cursor Object 6073 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6074 ** 6075 ** Every [virtual table module] implementation uses a subclass of the 6076 ** following structure to describe cursors that point into the 6077 ** [virtual table] and are used 6078 ** to loop through the virtual table. Cursors are created using the 6079 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6080 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6081 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6082 ** of the module. Each module implementation will define 6083 ** the content of a cursor structure to suit its own needs. 6084 ** 6085 ** This superclass exists in order to define fields of the cursor that 6086 ** are common to all implementations. 6087 */ 6088 struct sqlite3_vtab_cursor { 6089 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6090 /* Virtual table implementations will typically add additional fields */ 6091 }; 6092 6093 /* 6094 ** CAPI3REF: Declare The Schema Of A Virtual Table 6095 ** 6096 ** ^The [xCreate] and [xConnect] methods of a 6097 ** [virtual table module] call this interface 6098 ** to declare the format (the names and datatypes of the columns) of 6099 ** the virtual tables they implement. 6100 */ 6101 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6102 6103 /* 6104 ** CAPI3REF: Overload A Function For A Virtual Table 6105 ** METHOD: sqlite3 6106 ** 6107 ** ^(Virtual tables can provide alternative implementations of functions 6108 ** using the [xFindFunction] method of the [virtual table module]. 6109 ** But global versions of those functions 6110 ** must exist in order to be overloaded.)^ 6111 ** 6112 ** ^(This API makes sure a global version of a function with a particular 6113 ** name and number of parameters exists. If no such function exists 6114 ** before this API is called, a new function is created.)^ ^The implementation 6115 ** of the new function always causes an exception to be thrown. So 6116 ** the new function is not good for anything by itself. Its only 6117 ** purpose is to be a placeholder function that can be overloaded 6118 ** by a [virtual table]. 6119 */ 6120 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6121 6122 /* 6123 ** The interface to the virtual-table mechanism defined above (back up 6124 ** to a comment remarkably similar to this one) is currently considered 6125 ** to be experimental. The interface might change in incompatible ways. 6126 ** If this is a problem for you, do not use the interface at this time. 6127 ** 6128 ** When the virtual-table mechanism stabilizes, we will declare the 6129 ** interface fixed, support it indefinitely, and remove this comment. 6130 */ 6131 6132 /* 6133 ** CAPI3REF: A Handle To An Open BLOB 6134 ** KEYWORDS: {BLOB handle} {BLOB handles} 6135 ** 6136 ** An instance of this object represents an open BLOB on which 6137 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6138 ** ^Objects of this type are created by [sqlite3_blob_open()] 6139 ** and destroyed by [sqlite3_blob_close()]. 6140 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6141 ** can be used to read or write small subsections of the BLOB. 6142 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6143 */ 6144 typedef struct sqlite3_blob sqlite3_blob; 6145 6146 /* 6147 ** CAPI3REF: Open A BLOB For Incremental I/O 6148 ** METHOD: sqlite3 6149 ** CONSTRUCTOR: sqlite3_blob 6150 ** 6151 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6152 ** in row iRow, column zColumn, table zTable in database zDb; 6153 ** in other words, the same BLOB that would be selected by: 6154 ** 6155 ** <pre> 6156 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6157 ** </pre>)^ 6158 ** 6159 ** ^(Parameter zDb is not the filename that contains the database, but 6160 ** rather the symbolic name of the database. For attached databases, this is 6161 ** the name that appears after the AS keyword in the [ATTACH] statement. 6162 ** For the main database file, the database name is "main". For TEMP 6163 ** tables, the database name is "temp".)^ 6164 ** 6165 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6166 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6167 ** read-only access. 6168 ** 6169 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6170 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6171 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6172 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6173 ** on *ppBlob after this function it returns. 6174 ** 6175 ** This function fails with SQLITE_ERROR if any of the following are true: 6176 ** <ul> 6177 ** <li> ^(Database zDb does not exist)^, 6178 ** <li> ^(Table zTable does not exist within database zDb)^, 6179 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6180 ** <li> ^(Column zColumn does not exist)^, 6181 ** <li> ^(Row iRow is not present in the table)^, 6182 ** <li> ^(The specified column of row iRow contains a value that is not 6183 ** a TEXT or BLOB value)^, 6184 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6185 ** constraint and the blob is being opened for read/write access)^, 6186 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6187 ** column zColumn is part of a [child key] definition and the blob is 6188 ** being opened for read/write access)^. 6189 ** </ul> 6190 ** 6191 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6192 ** [database connection] error code and message accessible via 6193 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6194 ** 6195 ** 6196 ** ^(If the row that a BLOB handle points to is modified by an 6197 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6198 ** then the BLOB handle is marked as "expired". 6199 ** This is true if any column of the row is changed, even a column 6200 ** other than the one the BLOB handle is open on.)^ 6201 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6202 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6203 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6204 ** rolled back by the expiration of the BLOB. Such changes will eventually 6205 ** commit if the transaction continues to completion.)^ 6206 ** 6207 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6208 ** the opened blob. ^The size of a blob may not be changed by this 6209 ** interface. Use the [UPDATE] SQL command to change the size of a 6210 ** blob. 6211 ** 6212 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6213 ** and the built-in [zeroblob] SQL function may be used to create a 6214 ** zero-filled blob to read or write using the incremental-blob interface. 6215 ** 6216 ** To avoid a resource leak, every open [BLOB handle] should eventually 6217 ** be released by a call to [sqlite3_blob_close()]. 6218 */ 6219 SQLITE_API int sqlite3_blob_open( 6220 sqlite3*, 6221 const char *zDb, 6222 const char *zTable, 6223 const char *zColumn, 6224 sqlite3_int64 iRow, 6225 int flags, 6226 sqlite3_blob **ppBlob 6227 ); 6228 6229 /* 6230 ** CAPI3REF: Move a BLOB Handle to a New Row 6231 ** METHOD: sqlite3_blob 6232 ** 6233 ** ^This function is used to move an existing blob handle so that it points 6234 ** to a different row of the same database table. ^The new row is identified 6235 ** by the rowid value passed as the second argument. Only the row can be 6236 ** changed. ^The database, table and column on which the blob handle is open 6237 ** remain the same. Moving an existing blob handle to a new row can be 6238 ** faster than closing the existing handle and opening a new one. 6239 ** 6240 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6241 ** it must exist and there must be either a blob or text value stored in 6242 ** the nominated column.)^ ^If the new row is not present in the table, or if 6243 ** it does not contain a blob or text value, or if another error occurs, an 6244 ** SQLite error code is returned and the blob handle is considered aborted. 6245 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6246 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6247 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6248 ** always returns zero. 6249 ** 6250 ** ^This function sets the database handle error code and message. 6251 */ 6252 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6253 6254 /* 6255 ** CAPI3REF: Close A BLOB Handle 6256 ** DESTRUCTOR: sqlite3_blob 6257 ** 6258 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6259 ** unconditionally. Even if this routine returns an error code, the 6260 ** handle is still closed.)^ 6261 ** 6262 ** ^If the blob handle being closed was opened for read-write access, and if 6263 ** the database is in auto-commit mode and there are no other open read-write 6264 ** blob handles or active write statements, the current transaction is 6265 ** committed. ^If an error occurs while committing the transaction, an error 6266 ** code is returned and the transaction rolled back. 6267 ** 6268 ** Calling this function with an argument that is not a NULL pointer or an 6269 ** open blob handle results in undefined behaviour. ^Calling this routine 6270 ** with a null pointer (such as would be returned by a failed call to 6271 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6272 ** is passed a valid open blob handle, the values returned by the 6273 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6274 */ 6275 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6276 6277 /* 6278 ** CAPI3REF: Return The Size Of An Open BLOB 6279 ** METHOD: sqlite3_blob 6280 ** 6281 ** ^Returns the size in bytes of the BLOB accessible via the 6282 ** successfully opened [BLOB handle] in its only argument. ^The 6283 ** incremental blob I/O routines can only read or overwriting existing 6284 ** blob content; they cannot change the size of a blob. 6285 ** 6286 ** This routine only works on a [BLOB handle] which has been created 6287 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6288 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6289 ** to this routine results in undefined and probably undesirable behavior. 6290 */ 6291 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6292 6293 /* 6294 ** CAPI3REF: Read Data From A BLOB Incrementally 6295 ** METHOD: sqlite3_blob 6296 ** 6297 ** ^(This function is used to read data from an open [BLOB handle] into a 6298 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6299 ** from the open BLOB, starting at offset iOffset.)^ 6300 ** 6301 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6302 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6303 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6304 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6305 ** can be determined using the [sqlite3_blob_bytes()] interface. 6306 ** 6307 ** ^An attempt to read from an expired [BLOB handle] fails with an 6308 ** error code of [SQLITE_ABORT]. 6309 ** 6310 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6311 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6312 ** 6313 ** This routine only works on a [BLOB handle] which has been created 6314 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6315 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6316 ** to this routine results in undefined and probably undesirable behavior. 6317 ** 6318 ** See also: [sqlite3_blob_write()]. 6319 */ 6320 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6321 6322 /* 6323 ** CAPI3REF: Write Data Into A BLOB Incrementally 6324 ** METHOD: sqlite3_blob 6325 ** 6326 ** ^(This function is used to write data into an open [BLOB handle] from a 6327 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6328 ** into the open BLOB, starting at offset iOffset.)^ 6329 ** 6330 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6331 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6332 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6333 ** [database connection] error code and message accessible via 6334 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6335 ** 6336 ** ^If the [BLOB handle] passed as the first argument was not opened for 6337 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6338 ** this function returns [SQLITE_READONLY]. 6339 ** 6340 ** This function may only modify the contents of the BLOB; it is 6341 ** not possible to increase the size of a BLOB using this API. 6342 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6343 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6344 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6345 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6346 ** than zero [SQLITE_ERROR] is returned and no data is written. 6347 ** 6348 ** ^An attempt to write to an expired [BLOB handle] fails with an 6349 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6350 ** before the [BLOB handle] expired are not rolled back by the 6351 ** expiration of the handle, though of course those changes might 6352 ** have been overwritten by the statement that expired the BLOB handle 6353 ** or by other independent statements. 6354 ** 6355 ** This routine only works on a [BLOB handle] which has been created 6356 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6357 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6358 ** to this routine results in undefined and probably undesirable behavior. 6359 ** 6360 ** See also: [sqlite3_blob_read()]. 6361 */ 6362 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6363 6364 /* 6365 ** CAPI3REF: Virtual File System Objects 6366 ** 6367 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6368 ** that SQLite uses to interact 6369 ** with the underlying operating system. Most SQLite builds come with a 6370 ** single default VFS that is appropriate for the host computer. 6371 ** New VFSes can be registered and existing VFSes can be unregistered. 6372 ** The following interfaces are provided. 6373 ** 6374 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6375 ** ^Names are case sensitive. 6376 ** ^Names are zero-terminated UTF-8 strings. 6377 ** ^If there is no match, a NULL pointer is returned. 6378 ** ^If zVfsName is NULL then the default VFS is returned. 6379 ** 6380 ** ^New VFSes are registered with sqlite3_vfs_register(). 6381 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6382 ** ^The same VFS can be registered multiple times without injury. 6383 ** ^To make an existing VFS into the default VFS, register it again 6384 ** with the makeDflt flag set. If two different VFSes with the 6385 ** same name are registered, the behavior is undefined. If a 6386 ** VFS is registered with a name that is NULL or an empty string, 6387 ** then the behavior is undefined. 6388 ** 6389 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6390 ** ^(If the default VFS is unregistered, another VFS is chosen as 6391 ** the default. The choice for the new VFS is arbitrary.)^ 6392 */ 6393 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6394 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6395 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6396 6397 /* 6398 ** CAPI3REF: Mutexes 6399 ** 6400 ** The SQLite core uses these routines for thread 6401 ** synchronization. Though they are intended for internal 6402 ** use by SQLite, code that links against SQLite is 6403 ** permitted to use any of these routines. 6404 ** 6405 ** The SQLite source code contains multiple implementations 6406 ** of these mutex routines. An appropriate implementation 6407 ** is selected automatically at compile-time. The following 6408 ** implementations are available in the SQLite core: 6409 ** 6410 ** <ul> 6411 ** <li> SQLITE_MUTEX_PTHREADS 6412 ** <li> SQLITE_MUTEX_W32 6413 ** <li> SQLITE_MUTEX_NOOP 6414 ** </ul> 6415 ** 6416 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6417 ** that does no real locking and is appropriate for use in 6418 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6419 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6420 ** and Windows. 6421 ** 6422 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6423 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6424 ** implementation is included with the library. In this case the 6425 ** application must supply a custom mutex implementation using the 6426 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6427 ** before calling sqlite3_initialize() or any other public sqlite3_ 6428 ** function that calls sqlite3_initialize(). 6429 ** 6430 ** ^The sqlite3_mutex_alloc() routine allocates a new 6431 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6432 ** routine returns NULL if it is unable to allocate the requested 6433 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6434 ** integer constants: 6435 ** 6436 ** <ul> 6437 ** <li> SQLITE_MUTEX_FAST 6438 ** <li> SQLITE_MUTEX_RECURSIVE 6439 ** <li> SQLITE_MUTEX_STATIC_MASTER 6440 ** <li> SQLITE_MUTEX_STATIC_MEM 6441 ** <li> SQLITE_MUTEX_STATIC_OPEN 6442 ** <li> SQLITE_MUTEX_STATIC_PRNG 6443 ** <li> SQLITE_MUTEX_STATIC_LRU 6444 ** <li> SQLITE_MUTEX_STATIC_PMEM 6445 ** <li> SQLITE_MUTEX_STATIC_APP1 6446 ** <li> SQLITE_MUTEX_STATIC_APP2 6447 ** <li> SQLITE_MUTEX_STATIC_APP3 6448 ** <li> SQLITE_MUTEX_STATIC_VFS1 6449 ** <li> SQLITE_MUTEX_STATIC_VFS2 6450 ** <li> SQLITE_MUTEX_STATIC_VFS3 6451 ** </ul> 6452 ** 6453 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6454 ** cause sqlite3_mutex_alloc() to create 6455 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6456 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6457 ** The mutex implementation does not need to make a distinction 6458 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6459 ** not want to. SQLite will only request a recursive mutex in 6460 ** cases where it really needs one. If a faster non-recursive mutex 6461 ** implementation is available on the host platform, the mutex subsystem 6462 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6463 ** 6464 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6465 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6466 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6467 ** used by the current version of SQLite. Future versions of SQLite 6468 ** may add additional static mutexes. Static mutexes are for internal 6469 ** use by SQLite only. Applications that use SQLite mutexes should 6470 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6471 ** SQLITE_MUTEX_RECURSIVE. 6472 ** 6473 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6474 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6475 ** returns a different mutex on every call. ^For the static 6476 ** mutex types, the same mutex is returned on every call that has 6477 ** the same type number. 6478 ** 6479 ** ^The sqlite3_mutex_free() routine deallocates a previously 6480 ** allocated dynamic mutex. Attempting to deallocate a static 6481 ** mutex results in undefined behavior. 6482 ** 6483 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6484 ** to enter a mutex. ^If another thread is already within the mutex, 6485 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6486 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6487 ** upon successful entry. ^(Mutexes created using 6488 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6489 ** In such cases, the 6490 ** mutex must be exited an equal number of times before another thread 6491 ** can enter.)^ If the same thread tries to enter any mutex other 6492 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6493 ** 6494 ** ^(Some systems (for example, Windows 95) do not support the operation 6495 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6496 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6497 ** sqlite3_mutex_try() as an optimization so this is acceptable 6498 ** behavior.)^ 6499 ** 6500 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6501 ** previously entered by the same thread. The behavior 6502 ** is undefined if the mutex is not currently entered by the 6503 ** calling thread or is not currently allocated. 6504 ** 6505 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6506 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6507 ** behave as no-ops. 6508 ** 6509 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6510 */ 6511 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6512 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6513 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6514 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6515 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6516 6517 /* 6518 ** CAPI3REF: Mutex Methods Object 6519 ** 6520 ** An instance of this structure defines the low-level routines 6521 ** used to allocate and use mutexes. 6522 ** 6523 ** Usually, the default mutex implementations provided by SQLite are 6524 ** sufficient, however the application has the option of substituting a custom 6525 ** implementation for specialized deployments or systems for which SQLite 6526 ** does not provide a suitable implementation. In this case, the application 6527 ** creates and populates an instance of this structure to pass 6528 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6529 ** Additionally, an instance of this structure can be used as an 6530 ** output variable when querying the system for the current mutex 6531 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6532 ** 6533 ** ^The xMutexInit method defined by this structure is invoked as 6534 ** part of system initialization by the sqlite3_initialize() function. 6535 ** ^The xMutexInit routine is called by SQLite exactly once for each 6536 ** effective call to [sqlite3_initialize()]. 6537 ** 6538 ** ^The xMutexEnd method defined by this structure is invoked as 6539 ** part of system shutdown by the sqlite3_shutdown() function. The 6540 ** implementation of this method is expected to release all outstanding 6541 ** resources obtained by the mutex methods implementation, especially 6542 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6543 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6544 ** 6545 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6546 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6547 ** xMutexNotheld) implement the following interfaces (respectively): 6548 ** 6549 ** <ul> 6550 ** <li> [sqlite3_mutex_alloc()] </li> 6551 ** <li> [sqlite3_mutex_free()] </li> 6552 ** <li> [sqlite3_mutex_enter()] </li> 6553 ** <li> [sqlite3_mutex_try()] </li> 6554 ** <li> [sqlite3_mutex_leave()] </li> 6555 ** <li> [sqlite3_mutex_held()] </li> 6556 ** <li> [sqlite3_mutex_notheld()] </li> 6557 ** </ul>)^ 6558 ** 6559 ** The only difference is that the public sqlite3_XXX functions enumerated 6560 ** above silently ignore any invocations that pass a NULL pointer instead 6561 ** of a valid mutex handle. The implementations of the methods defined 6562 ** by this structure are not required to handle this case, the results 6563 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6564 ** (i.e. it is acceptable to provide an implementation that segfaults if 6565 ** it is passed a NULL pointer). 6566 ** 6567 ** The xMutexInit() method must be threadsafe. It must be harmless to 6568 ** invoke xMutexInit() multiple times within the same process and without 6569 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6570 ** xMutexInit() must be no-ops. 6571 ** 6572 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6573 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6574 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6575 ** memory allocation for a fast or recursive mutex. 6576 ** 6577 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6578 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6579 ** If xMutexInit fails in any way, it is expected to clean up after itself 6580 ** prior to returning. 6581 */ 6582 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6583 struct sqlite3_mutex_methods { 6584 int (*xMutexInit)(void); 6585 int (*xMutexEnd)(void); 6586 sqlite3_mutex *(*xMutexAlloc)(int); 6587 void (*xMutexFree)(sqlite3_mutex *); 6588 void (*xMutexEnter)(sqlite3_mutex *); 6589 int (*xMutexTry)(sqlite3_mutex *); 6590 void (*xMutexLeave)(sqlite3_mutex *); 6591 int (*xMutexHeld)(sqlite3_mutex *); 6592 int (*xMutexNotheld)(sqlite3_mutex *); 6593 }; 6594 6595 /* 6596 ** CAPI3REF: Mutex Verification Routines 6597 ** 6598 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6599 ** are intended for use inside assert() statements. The SQLite core 6600 ** never uses these routines except inside an assert() and applications 6601 ** are advised to follow the lead of the core. The SQLite core only 6602 ** provides implementations for these routines when it is compiled 6603 ** with the SQLITE_DEBUG flag. External mutex implementations 6604 ** are only required to provide these routines if SQLITE_DEBUG is 6605 ** defined and if NDEBUG is not defined. 6606 ** 6607 ** These routines should return true if the mutex in their argument 6608 ** is held or not held, respectively, by the calling thread. 6609 ** 6610 ** The implementation is not required to provide versions of these 6611 ** routines that actually work. If the implementation does not provide working 6612 ** versions of these routines, it should at least provide stubs that always 6613 ** return true so that one does not get spurious assertion failures. 6614 ** 6615 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6616 ** the routine should return 1. This seems counter-intuitive since 6617 ** clearly the mutex cannot be held if it does not exist. But 6618 ** the reason the mutex does not exist is because the build is not 6619 ** using mutexes. And we do not want the assert() containing the 6620 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6621 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6622 ** interface should also return 1 when given a NULL pointer. 6623 */ 6624 #ifndef NDEBUG 6625 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6626 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6627 #endif 6628 6629 /* 6630 ** CAPI3REF: Mutex Types 6631 ** 6632 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6633 ** which is one of these integer constants. 6634 ** 6635 ** The set of static mutexes may change from one SQLite release to the 6636 ** next. Applications that override the built-in mutex logic must be 6637 ** prepared to accommodate additional static mutexes. 6638 */ 6639 #define SQLITE_MUTEX_FAST 0 6640 #define SQLITE_MUTEX_RECURSIVE 1 6641 #define SQLITE_MUTEX_STATIC_MASTER 2 6642 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6643 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6644 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6645 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6646 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6647 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6648 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6649 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6650 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6651 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6652 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6653 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6654 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6655 6656 /* 6657 ** CAPI3REF: Retrieve the mutex for a database connection 6658 ** METHOD: sqlite3 6659 ** 6660 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6661 ** serializes access to the [database connection] given in the argument 6662 ** when the [threading mode] is Serialized. 6663 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6664 ** routine returns a NULL pointer. 6665 */ 6666 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6667 6668 /* 6669 ** CAPI3REF: Low-Level Control Of Database Files 6670 ** METHOD: sqlite3 6671 ** 6672 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6673 ** xFileControl method for the [sqlite3_io_methods] object associated 6674 ** with a particular database identified by the second argument. ^The 6675 ** name of the database is "main" for the main database or "temp" for the 6676 ** TEMP database, or the name that appears after the AS keyword for 6677 ** databases that are added using the [ATTACH] SQL command. 6678 ** ^A NULL pointer can be used in place of "main" to refer to the 6679 ** main database file. 6680 ** ^The third and fourth parameters to this routine 6681 ** are passed directly through to the second and third parameters of 6682 ** the xFileControl method. ^The return value of the xFileControl 6683 ** method becomes the return value of this routine. 6684 ** 6685 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6686 ** a pointer to the underlying [sqlite3_file] object to be written into 6687 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6688 ** case is a short-circuit path which does not actually invoke the 6689 ** underlying sqlite3_io_methods.xFileControl method. 6690 ** 6691 ** ^If the second parameter (zDbName) does not match the name of any 6692 ** open database file, then SQLITE_ERROR is returned. ^This error 6693 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6694 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6695 ** also return SQLITE_ERROR. There is no way to distinguish between 6696 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6697 ** xFileControl method. 6698 ** 6699 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6700 */ 6701 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6702 6703 /* 6704 ** CAPI3REF: Testing Interface 6705 ** 6706 ** ^The sqlite3_test_control() interface is used to read out internal 6707 ** state of SQLite and to inject faults into SQLite for testing 6708 ** purposes. ^The first parameter is an operation code that determines 6709 ** the number, meaning, and operation of all subsequent parameters. 6710 ** 6711 ** This interface is not for use by applications. It exists solely 6712 ** for verifying the correct operation of the SQLite library. Depending 6713 ** on how the SQLite library is compiled, this interface might not exist. 6714 ** 6715 ** The details of the operation codes, their meanings, the parameters 6716 ** they take, and what they do are all subject to change without notice. 6717 ** Unlike most of the SQLite API, this function is not guaranteed to 6718 ** operate consistently from one release to the next. 6719 */ 6720 SQLITE_API int sqlite3_test_control(int op, ...); 6721 6722 /* 6723 ** CAPI3REF: Testing Interface Operation Codes 6724 ** 6725 ** These constants are the valid operation code parameters used 6726 ** as the first argument to [sqlite3_test_control()]. 6727 ** 6728 ** These parameters and their meanings are subject to change 6729 ** without notice. These values are for testing purposes only. 6730 ** Applications should not use any of these parameters or the 6731 ** [sqlite3_test_control()] interface. 6732 */ 6733 #define SQLITE_TESTCTRL_FIRST 5 6734 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6735 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6736 #define SQLITE_TESTCTRL_PRNG_RESET 7 6737 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6738 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6739 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6740 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6741 #define SQLITE_TESTCTRL_ASSERT 12 6742 #define SQLITE_TESTCTRL_ALWAYS 13 6743 #define SQLITE_TESTCTRL_RESERVE 14 6744 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6745 #define SQLITE_TESTCTRL_ISKEYWORD 16 6746 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6747 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6748 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6749 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 6750 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6751 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6752 #define SQLITE_TESTCTRL_BYTEORDER 22 6753 #define SQLITE_TESTCTRL_ISINIT 23 6754 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6755 #define SQLITE_TESTCTRL_IMPOSTER 25 6756 #define SQLITE_TESTCTRL_LAST 25 6757 6758 /* 6759 ** CAPI3REF: SQLite Runtime Status 6760 ** 6761 ** ^These interfaces are used to retrieve runtime status information 6762 ** about the performance of SQLite, and optionally to reset various 6763 ** highwater marks. ^The first argument is an integer code for 6764 ** the specific parameter to measure. ^(Recognized integer codes 6765 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6766 ** ^The current value of the parameter is returned into *pCurrent. 6767 ** ^The highest recorded value is returned in *pHighwater. ^If the 6768 ** resetFlag is true, then the highest record value is reset after 6769 ** *pHighwater is written. ^(Some parameters do not record the highest 6770 ** value. For those parameters 6771 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6772 ** ^(Other parameters record only the highwater mark and not the current 6773 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6774 ** 6775 ** ^The sqlite3_status() and sqlite3_status64() routines return 6776 ** SQLITE_OK on success and a non-zero [error code] on failure. 6777 ** 6778 ** If either the current value or the highwater mark is too large to 6779 ** be represented by a 32-bit integer, then the values returned by 6780 ** sqlite3_status() are undefined. 6781 ** 6782 ** See also: [sqlite3_db_status()] 6783 */ 6784 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6785 SQLITE_API int sqlite3_status64( 6786 int op, 6787 sqlite3_int64 *pCurrent, 6788 sqlite3_int64 *pHighwater, 6789 int resetFlag 6790 ); 6791 6792 6793 /* 6794 ** CAPI3REF: Status Parameters 6795 ** KEYWORDS: {status parameters} 6796 ** 6797 ** These integer constants designate various run-time status parameters 6798 ** that can be returned by [sqlite3_status()]. 6799 ** 6800 ** <dl> 6801 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6802 ** <dd>This parameter is the current amount of memory checked out 6803 ** using [sqlite3_malloc()], either directly or indirectly. The 6804 ** figure includes calls made to [sqlite3_malloc()] by the application 6805 ** and internal memory usage by the SQLite library. Scratch memory 6806 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6807 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6808 ** this parameter. The amount returned is the sum of the allocation 6809 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6810 ** 6811 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6812 ** <dd>This parameter records the largest memory allocation request 6813 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6814 ** internal equivalents). Only the value returned in the 6815 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6816 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6817 ** 6818 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6819 ** <dd>This parameter records the number of separate memory allocations 6820 ** currently checked out.</dd>)^ 6821 ** 6822 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6823 ** <dd>This parameter returns the number of pages used out of the 6824 ** [pagecache memory allocator] that was configured using 6825 ** [SQLITE_CONFIG_PAGECACHE]. The 6826 ** value returned is in pages, not in bytes.</dd>)^ 6827 ** 6828 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6829 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6830 ** <dd>This parameter returns the number of bytes of page cache 6831 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6832 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6833 ** returned value includes allocations that overflowed because they 6834 ** where too large (they were larger than the "sz" parameter to 6835 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6836 ** no space was left in the page cache.</dd>)^ 6837 ** 6838 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6839 ** <dd>This parameter records the largest memory allocation request 6840 ** handed to [pagecache memory allocator]. Only the value returned in the 6841 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6842 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6843 ** 6844 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6845 ** <dd>This parameter returns the number of allocations used out of the 6846 ** [scratch memory allocator] configured using 6847 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6848 ** in bytes. Since a single thread may only have one scratch allocation 6849 ** outstanding at time, this parameter also reports the number of threads 6850 ** using scratch memory at the same time.</dd>)^ 6851 ** 6852 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6853 ** <dd>This parameter returns the number of bytes of scratch memory 6854 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6855 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6856 ** returned include overflows because the requested allocation was too 6857 ** larger (that is, because the requested allocation was larger than the 6858 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6859 ** slots were available. 6860 ** </dd>)^ 6861 ** 6862 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6863 ** <dd>This parameter records the largest memory allocation request 6864 ** handed to [scratch memory allocator]. Only the value returned in the 6865 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6866 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6867 ** 6868 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6869 ** <dd>The *pHighwater parameter records the deepest parser stack. 6870 ** The *pCurrent value is undefined. The *pHighwater value is only 6871 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6872 ** </dl> 6873 ** 6874 ** New status parameters may be added from time to time. 6875 */ 6876 #define SQLITE_STATUS_MEMORY_USED 0 6877 #define SQLITE_STATUS_PAGECACHE_USED 1 6878 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6879 #define SQLITE_STATUS_SCRATCH_USED 3 6880 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6881 #define SQLITE_STATUS_MALLOC_SIZE 5 6882 #define SQLITE_STATUS_PARSER_STACK 6 6883 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6884 #define SQLITE_STATUS_SCRATCH_SIZE 8 6885 #define SQLITE_STATUS_MALLOC_COUNT 9 6886 6887 /* 6888 ** CAPI3REF: Database Connection Status 6889 ** METHOD: sqlite3 6890 ** 6891 ** ^This interface is used to retrieve runtime status information 6892 ** about a single [database connection]. ^The first argument is the 6893 ** database connection object to be interrogated. ^The second argument 6894 ** is an integer constant, taken from the set of 6895 ** [SQLITE_DBSTATUS options], that 6896 ** determines the parameter to interrogate. The set of 6897 ** [SQLITE_DBSTATUS options] is likely 6898 ** to grow in future releases of SQLite. 6899 ** 6900 ** ^The current value of the requested parameter is written into *pCur 6901 ** and the highest instantaneous value is written into *pHiwtr. ^If 6902 ** the resetFlg is true, then the highest instantaneous value is 6903 ** reset back down to the current value. 6904 ** 6905 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6906 ** non-zero [error code] on failure. 6907 ** 6908 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6909 */ 6910 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6911 6912 /* 6913 ** CAPI3REF: Status Parameters for database connections 6914 ** KEYWORDS: {SQLITE_DBSTATUS options} 6915 ** 6916 ** These constants are the available integer "verbs" that can be passed as 6917 ** the second argument to the [sqlite3_db_status()] interface. 6918 ** 6919 ** New verbs may be added in future releases of SQLite. Existing verbs 6920 ** might be discontinued. Applications should check the return code from 6921 ** [sqlite3_db_status()] to make sure that the call worked. 6922 ** The [sqlite3_db_status()] interface will return a non-zero error code 6923 ** if a discontinued or unsupported verb is invoked. 6924 ** 6925 ** <dl> 6926 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6927 ** <dd>This parameter returns the number of lookaside memory slots currently 6928 ** checked out.</dd>)^ 6929 ** 6930 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6931 ** <dd>This parameter returns the number malloc attempts that were 6932 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6933 ** the current value is always zero.)^ 6934 ** 6935 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6936 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6937 ** <dd>This parameter returns the number malloc attempts that might have 6938 ** been satisfied using lookaside memory but failed due to the amount of 6939 ** memory requested being larger than the lookaside slot size. 6940 ** Only the high-water value is meaningful; 6941 ** the current value is always zero.)^ 6942 ** 6943 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6944 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6945 ** <dd>This parameter returns the number malloc attempts that might have 6946 ** been satisfied using lookaside memory but failed due to all lookaside 6947 ** memory already being in use. 6948 ** Only the high-water value is meaningful; 6949 ** the current value is always zero.)^ 6950 ** 6951 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6952 ** <dd>This parameter returns the approximate number of bytes of heap 6953 ** memory used by all pager caches associated with the database connection.)^ 6954 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6955 ** 6956 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6957 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6958 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6959 ** pager cache is shared between two or more connections the bytes of heap 6960 ** memory used by that pager cache is divided evenly between the attached 6961 ** connections.)^ In other words, if none of the pager caches associated 6962 ** with the database connection are shared, this request returns the same 6963 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 6964 ** shared, the value returned by this call will be smaller than that returned 6965 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 6966 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 6967 ** 6968 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6969 ** <dd>This parameter returns the approximate number of bytes of heap 6970 ** memory used to store the schema for all databases associated 6971 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6972 ** ^The full amount of memory used by the schemas is reported, even if the 6973 ** schema memory is shared with other database connections due to 6974 ** [shared cache mode] being enabled. 6975 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6976 ** 6977 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6978 ** <dd>This parameter returns the approximate number of bytes of heap 6979 ** and lookaside memory used by all prepared statements associated with 6980 ** the database connection.)^ 6981 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6982 ** </dd> 6983 ** 6984 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6985 ** <dd>This parameter returns the number of pager cache hits that have 6986 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6987 ** is always 0. 6988 ** </dd> 6989 ** 6990 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6991 ** <dd>This parameter returns the number of pager cache misses that have 6992 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6993 ** is always 0. 6994 ** </dd> 6995 ** 6996 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6997 ** <dd>This parameter returns the number of dirty cache entries that have 6998 ** been written to disk. Specifically, the number of pages written to the 6999 ** wal file in wal mode databases, or the number of pages written to the 7000 ** database file in rollback mode databases. Any pages written as part of 7001 ** transaction rollback or database recovery operations are not included. 7002 ** If an IO or other error occurs while writing a page to disk, the effect 7003 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7004 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7005 ** </dd> 7006 ** 7007 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7008 ** <dd>This parameter returns zero for the current value if and only if 7009 ** all foreign key constraints (deferred or immediate) have been 7010 ** resolved.)^ ^The highwater mark is always 0. 7011 ** </dd> 7012 ** </dl> 7013 */ 7014 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7015 #define SQLITE_DBSTATUS_CACHE_USED 1 7016 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7017 #define SQLITE_DBSTATUS_STMT_USED 3 7018 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7019 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7020 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7021 #define SQLITE_DBSTATUS_CACHE_HIT 7 7022 #define SQLITE_DBSTATUS_CACHE_MISS 8 7023 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7024 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7025 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7026 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 7027 7028 7029 /* 7030 ** CAPI3REF: Prepared Statement Status 7031 ** METHOD: sqlite3_stmt 7032 ** 7033 ** ^(Each prepared statement maintains various 7034 ** [SQLITE_STMTSTATUS counters] that measure the number 7035 ** of times it has performed specific operations.)^ These counters can 7036 ** be used to monitor the performance characteristics of the prepared 7037 ** statements. For example, if the number of table steps greatly exceeds 7038 ** the number of table searches or result rows, that would tend to indicate 7039 ** that the prepared statement is using a full table scan rather than 7040 ** an index. 7041 ** 7042 ** ^(This interface is used to retrieve and reset counter values from 7043 ** a [prepared statement]. The first argument is the prepared statement 7044 ** object to be interrogated. The second argument 7045 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7046 ** to be interrogated.)^ 7047 ** ^The current value of the requested counter is returned. 7048 ** ^If the resetFlg is true, then the counter is reset to zero after this 7049 ** interface call returns. 7050 ** 7051 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7052 */ 7053 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7054 7055 /* 7056 ** CAPI3REF: Status Parameters for prepared statements 7057 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7058 ** 7059 ** These preprocessor macros define integer codes that name counter 7060 ** values associated with the [sqlite3_stmt_status()] interface. 7061 ** The meanings of the various counters are as follows: 7062 ** 7063 ** <dl> 7064 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7065 ** <dd>^This is the number of times that SQLite has stepped forward in 7066 ** a table as part of a full table scan. Large numbers for this counter 7067 ** may indicate opportunities for performance improvement through 7068 ** careful use of indices.</dd> 7069 ** 7070 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7071 ** <dd>^This is the number of sort operations that have occurred. 7072 ** A non-zero value in this counter may indicate an opportunity to 7073 ** improvement performance through careful use of indices.</dd> 7074 ** 7075 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7076 ** <dd>^This is the number of rows inserted into transient indices that 7077 ** were created automatically in order to help joins run faster. 7078 ** A non-zero value in this counter may indicate an opportunity to 7079 ** improvement performance by adding permanent indices that do not 7080 ** need to be reinitialized each time the statement is run.</dd> 7081 ** 7082 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7083 ** <dd>^This is the number of virtual machine operations executed 7084 ** by the prepared statement if that number is less than or equal 7085 ** to 2147483647. The number of virtual machine operations can be 7086 ** used as a proxy for the total work done by the prepared statement. 7087 ** If the number of virtual machine operations exceeds 2147483647 7088 ** then the value returned by this statement status code is undefined. 7089 ** </dd> 7090 ** </dl> 7091 */ 7092 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7093 #define SQLITE_STMTSTATUS_SORT 2 7094 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7095 #define SQLITE_STMTSTATUS_VM_STEP 4 7096 7097 /* 7098 ** CAPI3REF: Custom Page Cache Object 7099 ** 7100 ** The sqlite3_pcache type is opaque. It is implemented by 7101 ** the pluggable module. The SQLite core has no knowledge of 7102 ** its size or internal structure and never deals with the 7103 ** sqlite3_pcache object except by holding and passing pointers 7104 ** to the object. 7105 ** 7106 ** See [sqlite3_pcache_methods2] for additional information. 7107 */ 7108 typedef struct sqlite3_pcache sqlite3_pcache; 7109 7110 /* 7111 ** CAPI3REF: Custom Page Cache Object 7112 ** 7113 ** The sqlite3_pcache_page object represents a single page in the 7114 ** page cache. The page cache will allocate instances of this 7115 ** object. Various methods of the page cache use pointers to instances 7116 ** of this object as parameters or as their return value. 7117 ** 7118 ** See [sqlite3_pcache_methods2] for additional information. 7119 */ 7120 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7121 struct sqlite3_pcache_page { 7122 void *pBuf; /* The content of the page */ 7123 void *pExtra; /* Extra information associated with the page */ 7124 }; 7125 7126 /* 7127 ** CAPI3REF: Application Defined Page Cache. 7128 ** KEYWORDS: {page cache} 7129 ** 7130 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7131 ** register an alternative page cache implementation by passing in an 7132 ** instance of the sqlite3_pcache_methods2 structure.)^ 7133 ** In many applications, most of the heap memory allocated by 7134 ** SQLite is used for the page cache. 7135 ** By implementing a 7136 ** custom page cache using this API, an application can better control 7137 ** the amount of memory consumed by SQLite, the way in which 7138 ** that memory is allocated and released, and the policies used to 7139 ** determine exactly which parts of a database file are cached and for 7140 ** how long. 7141 ** 7142 ** The alternative page cache mechanism is an 7143 ** extreme measure that is only needed by the most demanding applications. 7144 ** The built-in page cache is recommended for most uses. 7145 ** 7146 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7147 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7148 ** the application may discard the parameter after the call to 7149 ** [sqlite3_config()] returns.)^ 7150 ** 7151 ** [[the xInit() page cache method]] 7152 ** ^(The xInit() method is called once for each effective 7153 ** call to [sqlite3_initialize()])^ 7154 ** (usually only once during the lifetime of the process). ^(The xInit() 7155 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7156 ** The intent of the xInit() method is to set up global data structures 7157 ** required by the custom page cache implementation. 7158 ** ^(If the xInit() method is NULL, then the 7159 ** built-in default page cache is used instead of the application defined 7160 ** page cache.)^ 7161 ** 7162 ** [[the xShutdown() page cache method]] 7163 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7164 ** It can be used to clean up 7165 ** any outstanding resources before process shutdown, if required. 7166 ** ^The xShutdown() method may be NULL. 7167 ** 7168 ** ^SQLite automatically serializes calls to the xInit method, 7169 ** so the xInit method need not be threadsafe. ^The 7170 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7171 ** not need to be threadsafe either. All other methods must be threadsafe 7172 ** in multithreaded applications. 7173 ** 7174 ** ^SQLite will never invoke xInit() more than once without an intervening 7175 ** call to xShutdown(). 7176 ** 7177 ** [[the xCreate() page cache methods]] 7178 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7179 ** SQLite will typically create one cache instance for each open database file, 7180 ** though this is not guaranteed. ^The 7181 ** first parameter, szPage, is the size in bytes of the pages that must 7182 ** be allocated by the cache. ^szPage will always a power of two. ^The 7183 ** second parameter szExtra is a number of bytes of extra storage 7184 ** associated with each page cache entry. ^The szExtra parameter will 7185 ** a number less than 250. SQLite will use the 7186 ** extra szExtra bytes on each page to store metadata about the underlying 7187 ** database page on disk. The value passed into szExtra depends 7188 ** on the SQLite version, the target platform, and how SQLite was compiled. 7189 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7190 ** created will be used to cache database pages of a file stored on disk, or 7191 ** false if it is used for an in-memory database. The cache implementation 7192 ** does not have to do anything special based with the value of bPurgeable; 7193 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7194 ** never invoke xUnpin() except to deliberately delete a page. 7195 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7196 ** false will always have the "discard" flag set to true. 7197 ** ^Hence, a cache created with bPurgeable false will 7198 ** never contain any unpinned pages. 7199 ** 7200 ** [[the xCachesize() page cache method]] 7201 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7202 ** suggested maximum cache-size (number of pages stored by) the cache 7203 ** instance passed as the first argument. This is the value configured using 7204 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7205 ** parameter, the implementation is not required to do anything with this 7206 ** value; it is advisory only. 7207 ** 7208 ** [[the xPagecount() page cache methods]] 7209 ** The xPagecount() method must return the number of pages currently 7210 ** stored in the cache, both pinned and unpinned. 7211 ** 7212 ** [[the xFetch() page cache methods]] 7213 ** The xFetch() method locates a page in the cache and returns a pointer to 7214 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7215 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7216 ** pointer to a buffer of szPage bytes used to store the content of a 7217 ** single database page. The pExtra element of sqlite3_pcache_page will be 7218 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7219 ** for each entry in the page cache. 7220 ** 7221 ** The page to be fetched is determined by the key. ^The minimum key value 7222 ** is 1. After it has been retrieved using xFetch, the page is considered 7223 ** to be "pinned". 7224 ** 7225 ** If the requested page is already in the page cache, then the page cache 7226 ** implementation must return a pointer to the page buffer with its content 7227 ** intact. If the requested page is not already in the cache, then the 7228 ** cache implementation should use the value of the createFlag 7229 ** parameter to help it determined what action to take: 7230 ** 7231 ** <table border=1 width=85% align=center> 7232 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7233 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7234 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7235 ** Otherwise return NULL. 7236 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7237 ** NULL if allocating a new page is effectively impossible. 7238 ** </table> 7239 ** 7240 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7241 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7242 ** failed.)^ In between the to xFetch() calls, SQLite may 7243 ** attempt to unpin one or more cache pages by spilling the content of 7244 ** pinned pages to disk and synching the operating system disk cache. 7245 ** 7246 ** [[the xUnpin() page cache method]] 7247 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7248 ** as its second argument. If the third parameter, discard, is non-zero, 7249 ** then the page must be evicted from the cache. 7250 ** ^If the discard parameter is 7251 ** zero, then the page may be discarded or retained at the discretion of 7252 ** page cache implementation. ^The page cache implementation 7253 ** may choose to evict unpinned pages at any time. 7254 ** 7255 ** The cache must not perform any reference counting. A single 7256 ** call to xUnpin() unpins the page regardless of the number of prior calls 7257 ** to xFetch(). 7258 ** 7259 ** [[the xRekey() page cache methods]] 7260 ** The xRekey() method is used to change the key value associated with the 7261 ** page passed as the second argument. If the cache 7262 ** previously contains an entry associated with newKey, it must be 7263 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7264 ** to be pinned. 7265 ** 7266 ** When SQLite calls the xTruncate() method, the cache must discard all 7267 ** existing cache entries with page numbers (keys) greater than or equal 7268 ** to the value of the iLimit parameter passed to xTruncate(). If any 7269 ** of these pages are pinned, they are implicitly unpinned, meaning that 7270 ** they can be safely discarded. 7271 ** 7272 ** [[the xDestroy() page cache method]] 7273 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7274 ** All resources associated with the specified cache should be freed. ^After 7275 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7276 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7277 ** functions. 7278 ** 7279 ** [[the xShrink() page cache method]] 7280 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7281 ** free up as much of heap memory as possible. The page cache implementation 7282 ** is not obligated to free any memory, but well-behaved implementations should 7283 ** do their best. 7284 */ 7285 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7286 struct sqlite3_pcache_methods2 { 7287 int iVersion; 7288 void *pArg; 7289 int (*xInit)(void*); 7290 void (*xShutdown)(void*); 7291 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7292 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7293 int (*xPagecount)(sqlite3_pcache*); 7294 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7295 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7296 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7297 unsigned oldKey, unsigned newKey); 7298 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7299 void (*xDestroy)(sqlite3_pcache*); 7300 void (*xShrink)(sqlite3_pcache*); 7301 }; 7302 7303 /* 7304 ** This is the obsolete pcache_methods object that has now been replaced 7305 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7306 ** retained in the header file for backwards compatibility only. 7307 */ 7308 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7309 struct sqlite3_pcache_methods { 7310 void *pArg; 7311 int (*xInit)(void*); 7312 void (*xShutdown)(void*); 7313 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7314 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7315 int (*xPagecount)(sqlite3_pcache*); 7316 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7317 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7318 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7319 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7320 void (*xDestroy)(sqlite3_pcache*); 7321 }; 7322 7323 7324 /* 7325 ** CAPI3REF: Online Backup Object 7326 ** 7327 ** The sqlite3_backup object records state information about an ongoing 7328 ** online backup operation. ^The sqlite3_backup object is created by 7329 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7330 ** [sqlite3_backup_finish()]. 7331 ** 7332 ** See Also: [Using the SQLite Online Backup API] 7333 */ 7334 typedef struct sqlite3_backup sqlite3_backup; 7335 7336 /* 7337 ** CAPI3REF: Online Backup API. 7338 ** 7339 ** The backup API copies the content of one database into another. 7340 ** It is useful either for creating backups of databases or 7341 ** for copying in-memory databases to or from persistent files. 7342 ** 7343 ** See Also: [Using the SQLite Online Backup API] 7344 ** 7345 ** ^SQLite holds a write transaction open on the destination database file 7346 ** for the duration of the backup operation. 7347 ** ^The source database is read-locked only while it is being read; 7348 ** it is not locked continuously for the entire backup operation. 7349 ** ^Thus, the backup may be performed on a live source database without 7350 ** preventing other database connections from 7351 ** reading or writing to the source database while the backup is underway. 7352 ** 7353 ** ^(To perform a backup operation: 7354 ** <ol> 7355 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7356 ** backup, 7357 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7358 ** the data between the two databases, and finally 7359 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7360 ** associated with the backup operation. 7361 ** </ol>)^ 7362 ** There should be exactly one call to sqlite3_backup_finish() for each 7363 ** successful call to sqlite3_backup_init(). 7364 ** 7365 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7366 ** 7367 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7368 ** [database connection] associated with the destination database 7369 ** and the database name, respectively. 7370 ** ^The database name is "main" for the main database, "temp" for the 7371 ** temporary database, or the name specified after the AS keyword in 7372 ** an [ATTACH] statement for an attached database. 7373 ** ^The S and M arguments passed to 7374 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7375 ** and database name of the source database, respectively. 7376 ** ^The source and destination [database connections] (parameters S and D) 7377 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7378 ** an error. 7379 ** 7380 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7381 ** there is already a read or read-write transaction open on the 7382 ** destination database. 7383 ** 7384 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7385 ** returned and an error code and error message are stored in the 7386 ** destination [database connection] D. 7387 ** ^The error code and message for the failed call to sqlite3_backup_init() 7388 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7389 ** [sqlite3_errmsg16()] functions. 7390 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7391 ** [sqlite3_backup] object. 7392 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7393 ** sqlite3_backup_finish() functions to perform the specified backup 7394 ** operation. 7395 ** 7396 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7397 ** 7398 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7399 ** the source and destination databases specified by [sqlite3_backup] object B. 7400 ** ^If N is negative, all remaining source pages are copied. 7401 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7402 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7403 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7404 ** from source to destination, then it returns [SQLITE_DONE]. 7405 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7406 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7407 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7408 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7409 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7410 ** 7411 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7412 ** <ol> 7413 ** <li> the destination database was opened read-only, or 7414 ** <li> the destination database is using write-ahead-log journaling 7415 ** and the destination and source page sizes differ, or 7416 ** <li> the destination database is an in-memory database and the 7417 ** destination and source page sizes differ. 7418 ** </ol>)^ 7419 ** 7420 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7421 ** the [sqlite3_busy_handler | busy-handler function] 7422 ** is invoked (if one is specified). ^If the 7423 ** busy-handler returns non-zero before the lock is available, then 7424 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7425 ** sqlite3_backup_step() can be retried later. ^If the source 7426 ** [database connection] 7427 ** is being used to write to the source database when sqlite3_backup_step() 7428 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7429 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7430 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7431 ** [SQLITE_READONLY] is returned, then 7432 ** there is no point in retrying the call to sqlite3_backup_step(). These 7433 ** errors are considered fatal.)^ The application must accept 7434 ** that the backup operation has failed and pass the backup operation handle 7435 ** to the sqlite3_backup_finish() to release associated resources. 7436 ** 7437 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7438 ** on the destination file. ^The exclusive lock is not released until either 7439 ** sqlite3_backup_finish() is called or the backup operation is complete 7440 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7441 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7442 ** lasts for the duration of the sqlite3_backup_step() call. 7443 ** ^Because the source database is not locked between calls to 7444 ** sqlite3_backup_step(), the source database may be modified mid-way 7445 ** through the backup process. ^If the source database is modified by an 7446 ** external process or via a database connection other than the one being 7447 ** used by the backup operation, then the backup will be automatically 7448 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7449 ** database is modified by the using the same database connection as is used 7450 ** by the backup operation, then the backup database is automatically 7451 ** updated at the same time. 7452 ** 7453 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7454 ** 7455 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7456 ** application wishes to abandon the backup operation, the application 7457 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7458 ** ^The sqlite3_backup_finish() interfaces releases all 7459 ** resources associated with the [sqlite3_backup] object. 7460 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7461 ** active write-transaction on the destination database is rolled back. 7462 ** The [sqlite3_backup] object is invalid 7463 ** and may not be used following a call to sqlite3_backup_finish(). 7464 ** 7465 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7466 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7467 ** sqlite3_backup_step() completed. 7468 ** ^If an out-of-memory condition or IO error occurred during any prior 7469 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7470 ** sqlite3_backup_finish() returns the corresponding [error code]. 7471 ** 7472 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7473 ** is not a permanent error and does not affect the return value of 7474 ** sqlite3_backup_finish(). 7475 ** 7476 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7477 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7478 ** 7479 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7480 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7481 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7482 ** in the source database at the conclusion of the most recent 7483 ** sqlite3_backup_step(). 7484 ** ^(The values returned by these functions are only updated by 7485 ** sqlite3_backup_step(). If the source database is modified in a way that 7486 ** changes the size of the source database or the number of pages remaining, 7487 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7488 ** and sqlite3_backup_remaining() until after the next 7489 ** sqlite3_backup_step().)^ 7490 ** 7491 ** <b>Concurrent Usage of Database Handles</b> 7492 ** 7493 ** ^The source [database connection] may be used by the application for other 7494 ** purposes while a backup operation is underway or being initialized. 7495 ** ^If SQLite is compiled and configured to support threadsafe database 7496 ** connections, then the source database connection may be used concurrently 7497 ** from within other threads. 7498 ** 7499 ** However, the application must guarantee that the destination 7500 ** [database connection] is not passed to any other API (by any thread) after 7501 ** sqlite3_backup_init() is called and before the corresponding call to 7502 ** sqlite3_backup_finish(). SQLite does not currently check to see 7503 ** if the application incorrectly accesses the destination [database connection] 7504 ** and so no error code is reported, but the operations may malfunction 7505 ** nevertheless. Use of the destination database connection while a 7506 ** backup is in progress might also also cause a mutex deadlock. 7507 ** 7508 ** If running in [shared cache mode], the application must 7509 ** guarantee that the shared cache used by the destination database 7510 ** is not accessed while the backup is running. In practice this means 7511 ** that the application must guarantee that the disk file being 7512 ** backed up to is not accessed by any connection within the process, 7513 ** not just the specific connection that was passed to sqlite3_backup_init(). 7514 ** 7515 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7516 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7517 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7518 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7519 ** same time as another thread is invoking sqlite3_backup_step() it is 7520 ** possible that they return invalid values. 7521 */ 7522 SQLITE_API sqlite3_backup *sqlite3_backup_init( 7523 sqlite3 *pDest, /* Destination database handle */ 7524 const char *zDestName, /* Destination database name */ 7525 sqlite3 *pSource, /* Source database handle */ 7526 const char *zSourceName /* Source database name */ 7527 ); 7528 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7529 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7530 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7531 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7532 7533 /* 7534 ** CAPI3REF: Unlock Notification 7535 ** METHOD: sqlite3 7536 ** 7537 ** ^When running in shared-cache mode, a database operation may fail with 7538 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7539 ** individual tables within the shared-cache cannot be obtained. See 7540 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7541 ** ^This API may be used to register a callback that SQLite will invoke 7542 ** when the connection currently holding the required lock relinquishes it. 7543 ** ^This API is only available if the library was compiled with the 7544 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7545 ** 7546 ** See Also: [Using the SQLite Unlock Notification Feature]. 7547 ** 7548 ** ^Shared-cache locks are released when a database connection concludes 7549 ** its current transaction, either by committing it or rolling it back. 7550 ** 7551 ** ^When a connection (known as the blocked connection) fails to obtain a 7552 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7553 ** identity of the database connection (the blocking connection) that 7554 ** has locked the required resource is stored internally. ^After an 7555 ** application receives an SQLITE_LOCKED error, it may call the 7556 ** sqlite3_unlock_notify() method with the blocked connection handle as 7557 ** the first argument to register for a callback that will be invoked 7558 ** when the blocking connections current transaction is concluded. ^The 7559 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7560 ** call that concludes the blocking connections transaction. 7561 ** 7562 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7563 ** there is a chance that the blocking connection will have already 7564 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7565 ** If this happens, then the specified callback is invoked immediately, 7566 ** from within the call to sqlite3_unlock_notify().)^ 7567 ** 7568 ** ^If the blocked connection is attempting to obtain a write-lock on a 7569 ** shared-cache table, and more than one other connection currently holds 7570 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7571 ** the other connections to use as the blocking connection. 7572 ** 7573 ** ^(There may be at most one unlock-notify callback registered by a 7574 ** blocked connection. If sqlite3_unlock_notify() is called when the 7575 ** blocked connection already has a registered unlock-notify callback, 7576 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7577 ** called with a NULL pointer as its second argument, then any existing 7578 ** unlock-notify callback is canceled. ^The blocked connections 7579 ** unlock-notify callback may also be canceled by closing the blocked 7580 ** connection using [sqlite3_close()]. 7581 ** 7582 ** The unlock-notify callback is not reentrant. If an application invokes 7583 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7584 ** crash or deadlock may be the result. 7585 ** 7586 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7587 ** returns SQLITE_OK. 7588 ** 7589 ** <b>Callback Invocation Details</b> 7590 ** 7591 ** When an unlock-notify callback is registered, the application provides a 7592 ** single void* pointer that is passed to the callback when it is invoked. 7593 ** However, the signature of the callback function allows SQLite to pass 7594 ** it an array of void* context pointers. The first argument passed to 7595 ** an unlock-notify callback is a pointer to an array of void* pointers, 7596 ** and the second is the number of entries in the array. 7597 ** 7598 ** When a blocking connections transaction is concluded, there may be 7599 ** more than one blocked connection that has registered for an unlock-notify 7600 ** callback. ^If two or more such blocked connections have specified the 7601 ** same callback function, then instead of invoking the callback function 7602 ** multiple times, it is invoked once with the set of void* context pointers 7603 ** specified by the blocked connections bundled together into an array. 7604 ** This gives the application an opportunity to prioritize any actions 7605 ** related to the set of unblocked database connections. 7606 ** 7607 ** <b>Deadlock Detection</b> 7608 ** 7609 ** Assuming that after registering for an unlock-notify callback a 7610 ** database waits for the callback to be issued before taking any further 7611 ** action (a reasonable assumption), then using this API may cause the 7612 ** application to deadlock. For example, if connection X is waiting for 7613 ** connection Y's transaction to be concluded, and similarly connection 7614 ** Y is waiting on connection X's transaction, then neither connection 7615 ** will proceed and the system may remain deadlocked indefinitely. 7616 ** 7617 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7618 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7619 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7620 ** unlock-notify callback is registered. The system is said to be in 7621 ** a deadlocked state if connection A has registered for an unlock-notify 7622 ** callback on the conclusion of connection B's transaction, and connection 7623 ** B has itself registered for an unlock-notify callback when connection 7624 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7625 ** the system is also considered to be deadlocked if connection B has 7626 ** registered for an unlock-notify callback on the conclusion of connection 7627 ** C's transaction, where connection C is waiting on connection A. ^Any 7628 ** number of levels of indirection are allowed. 7629 ** 7630 ** <b>The "DROP TABLE" Exception</b> 7631 ** 7632 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7633 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7634 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7635 ** SQLite checks if there are any currently executing SELECT statements 7636 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7637 ** returned. In this case there is no "blocking connection", so invoking 7638 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7639 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7640 ** or "DROP INDEX" query, an infinite loop might be the result. 7641 ** 7642 ** One way around this problem is to check the extended error code returned 7643 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7644 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7645 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7646 ** SQLITE_LOCKED.)^ 7647 */ 7648 SQLITE_API int sqlite3_unlock_notify( 7649 sqlite3 *pBlocked, /* Waiting connection */ 7650 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7651 void *pNotifyArg /* Argument to pass to xNotify */ 7652 ); 7653 7654 7655 /* 7656 ** CAPI3REF: String Comparison 7657 ** 7658 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7659 ** and extensions to compare the contents of two buffers containing UTF-8 7660 ** strings in a case-independent fashion, using the same definition of "case 7661 ** independence" that SQLite uses internally when comparing identifiers. 7662 */ 7663 SQLITE_API int sqlite3_stricmp(const char *, const char *); 7664 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7665 7666 /* 7667 ** CAPI3REF: String Globbing 7668 * 7669 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7670 ** string X matches the [GLOB] pattern P. 7671 ** ^The definition of [GLOB] pattern matching used in 7672 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7673 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7674 ** is case sensitive. 7675 ** 7676 ** Note that this routine returns zero on a match and non-zero if the strings 7677 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7678 ** 7679 ** See also: [sqlite3_strlike()]. 7680 */ 7681 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7682 7683 /* 7684 ** CAPI3REF: String LIKE Matching 7685 * 7686 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7687 ** string X matches the [LIKE] pattern P with escape character E. 7688 ** ^The definition of [LIKE] pattern matching used in 7689 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7690 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7691 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7692 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7693 ** insensitive - equivalent upper and lower case ASCII characters match 7694 ** one another. 7695 ** 7696 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7697 ** only ASCII characters are case folded. 7698 ** 7699 ** Note that this routine returns zero on a match and non-zero if the strings 7700 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7701 ** 7702 ** See also: [sqlite3_strglob()]. 7703 */ 7704 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7705 7706 /* 7707 ** CAPI3REF: Error Logging Interface 7708 ** 7709 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7710 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7711 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7712 ** used with [sqlite3_snprintf()] to generate the final output string. 7713 ** 7714 ** The sqlite3_log() interface is intended for use by extensions such as 7715 ** virtual tables, collating functions, and SQL functions. While there is 7716 ** nothing to prevent an application from calling sqlite3_log(), doing so 7717 ** is considered bad form. 7718 ** 7719 ** The zFormat string must not be NULL. 7720 ** 7721 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7722 ** will not use dynamically allocated memory. The log message is stored in 7723 ** a fixed-length buffer on the stack. If the log message is longer than 7724 ** a few hundred characters, it will be truncated to the length of the 7725 ** buffer. 7726 */ 7727 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7728 7729 /* 7730 ** CAPI3REF: Write-Ahead Log Commit Hook 7731 ** METHOD: sqlite3 7732 ** 7733 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7734 ** is invoked each time data is committed to a database in wal mode. 7735 ** 7736 ** ^(The callback is invoked by SQLite after the commit has taken place and 7737 ** the associated write-lock on the database released)^, so the implementation 7738 ** may read, write or [checkpoint] the database as required. 7739 ** 7740 ** ^The first parameter passed to the callback function when it is invoked 7741 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7742 ** registering the callback. ^The second is a copy of the database handle. 7743 ** ^The third parameter is the name of the database that was written to - 7744 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7745 ** is the number of pages currently in the write-ahead log file, 7746 ** including those that were just committed. 7747 ** 7748 ** The callback function should normally return [SQLITE_OK]. ^If an error 7749 ** code is returned, that error will propagate back up through the 7750 ** SQLite code base to cause the statement that provoked the callback 7751 ** to report an error, though the commit will have still occurred. If the 7752 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7753 ** that does not correspond to any valid SQLite error code, the results 7754 ** are undefined. 7755 ** 7756 ** A single database handle may have at most a single write-ahead log callback 7757 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7758 ** previously registered write-ahead log callback. ^Note that the 7759 ** [sqlite3_wal_autocheckpoint()] interface and the 7760 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7761 ** overwrite any prior [sqlite3_wal_hook()] settings. 7762 */ 7763 SQLITE_API void *sqlite3_wal_hook( 7764 sqlite3*, 7765 int(*)(void *,sqlite3*,const char*,int), 7766 void* 7767 ); 7768 7769 /* 7770 ** CAPI3REF: Configure an auto-checkpoint 7771 ** METHOD: sqlite3 7772 ** 7773 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7774 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7775 ** to automatically [checkpoint] 7776 ** after committing a transaction if there are N or 7777 ** more frames in the [write-ahead log] file. ^Passing zero or 7778 ** a negative value as the nFrame parameter disables automatic 7779 ** checkpoints entirely. 7780 ** 7781 ** ^The callback registered by this function replaces any existing callback 7782 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7783 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7784 ** configured by this function. 7785 ** 7786 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7787 ** from SQL. 7788 ** 7789 ** ^Checkpoints initiated by this mechanism are 7790 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7791 ** 7792 ** ^Every new [database connection] defaults to having the auto-checkpoint 7793 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7794 ** pages. The use of this interface 7795 ** is only necessary if the default setting is found to be suboptimal 7796 ** for a particular application. 7797 */ 7798 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7799 7800 /* 7801 ** CAPI3REF: Checkpoint a database 7802 ** METHOD: sqlite3 7803 ** 7804 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7805 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7806 ** 7807 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7808 ** [write-ahead log] for database X on [database connection] D to be 7809 ** transferred into the database file and for the write-ahead log to 7810 ** be reset. See the [checkpointing] documentation for addition 7811 ** information. 7812 ** 7813 ** This interface used to be the only way to cause a checkpoint to 7814 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7815 ** interface was added. This interface is retained for backwards 7816 ** compatibility and as a convenience for applications that need to manually 7817 ** start a callback but which do not need the full power (and corresponding 7818 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7819 */ 7820 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7821 7822 /* 7823 ** CAPI3REF: Checkpoint a database 7824 ** METHOD: sqlite3 7825 ** 7826 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7827 ** operation on database X of [database connection] D in mode M. Status 7828 ** information is written back into integers pointed to by L and C.)^ 7829 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7830 ** 7831 ** <dl> 7832 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7833 ** ^Checkpoint as many frames as possible without waiting for any database 7834 ** readers or writers to finish, then sync the database file if all frames 7835 ** in the log were checkpointed. ^The [busy-handler callback] 7836 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7837 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7838 ** if there are concurrent readers or writers. 7839 ** 7840 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7841 ** ^This mode blocks (it invokes the 7842 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7843 ** database writer and all readers are reading from the most recent database 7844 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7845 ** database file. ^This mode blocks new database writers while it is pending, 7846 ** but new database readers are allowed to continue unimpeded. 7847 ** 7848 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7849 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7850 ** that after checkpointing the log file it blocks (calls the 7851 ** [busy-handler callback]) 7852 ** until all readers are reading from the database file only. ^This ensures 7853 ** that the next writer will restart the log file from the beginning. 7854 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7855 ** database writer attempts while it is pending, but does not impede readers. 7856 ** 7857 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7858 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7859 ** addition that it also truncates the log file to zero bytes just prior 7860 ** to a successful return. 7861 ** </dl> 7862 ** 7863 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7864 ** the log file or to -1 if the checkpoint could not run because 7865 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7866 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7867 ** log file (including any that were already checkpointed before the function 7868 ** was called) or to -1 if the checkpoint could not run due to an error or 7869 ** because the database is not in WAL mode. ^Note that upon successful 7870 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7871 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7872 ** 7873 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7874 ** any other process is running a checkpoint operation at the same time, the 7875 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7876 ** busy-handler configured, it will not be invoked in this case. 7877 ** 7878 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7879 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7880 ** obtained immediately, and a busy-handler is configured, it is invoked and 7881 ** the writer lock retried until either the busy-handler returns 0 or the lock 7882 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7883 ** database readers as described above. ^If the busy-handler returns 0 before 7884 ** the writer lock is obtained or while waiting for database readers, the 7885 ** checkpoint operation proceeds from that point in the same way as 7886 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7887 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7888 ** 7889 ** ^If parameter zDb is NULL or points to a zero length string, then the 7890 ** specified operation is attempted on all WAL databases [attached] to 7891 ** [database connection] db. In this case the 7892 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7893 ** an SQLITE_BUSY error is encountered when processing one or more of the 7894 ** attached WAL databases, the operation is still attempted on any remaining 7895 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7896 ** error occurs while processing an attached database, processing is abandoned 7897 ** and the error code is returned to the caller immediately. ^If no error 7898 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7899 ** databases, SQLITE_OK is returned. 7900 ** 7901 ** ^If database zDb is the name of an attached database that is not in WAL 7902 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7903 ** zDb is not NULL (or a zero length string) and is not the name of any 7904 ** attached database, SQLITE_ERROR is returned to the caller. 7905 ** 7906 ** ^Unless it returns SQLITE_MISUSE, 7907 ** the sqlite3_wal_checkpoint_v2() interface 7908 ** sets the error information that is queried by 7909 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7910 ** 7911 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7912 ** from SQL. 7913 */ 7914 SQLITE_API int sqlite3_wal_checkpoint_v2( 7915 sqlite3 *db, /* Database handle */ 7916 const char *zDb, /* Name of attached database (or NULL) */ 7917 int eMode, /* SQLITE_CHECKPOINT_* value */ 7918 int *pnLog, /* OUT: Size of WAL log in frames */ 7919 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7920 ); 7921 7922 /* 7923 ** CAPI3REF: Checkpoint Mode Values 7924 ** KEYWORDS: {checkpoint mode} 7925 ** 7926 ** These constants define all valid values for the "checkpoint mode" passed 7927 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7928 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7929 ** meaning of each of these checkpoint modes. 7930 */ 7931 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7932 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7933 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7934 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7935 7936 /* 7937 ** CAPI3REF: Virtual Table Interface Configuration 7938 ** 7939 ** This function may be called by either the [xConnect] or [xCreate] method 7940 ** of a [virtual table] implementation to configure 7941 ** various facets of the virtual table interface. 7942 ** 7943 ** If this interface is invoked outside the context of an xConnect or 7944 ** xCreate virtual table method then the behavior is undefined. 7945 ** 7946 ** At present, there is only one option that may be configured using 7947 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7948 ** may be added in the future. 7949 */ 7950 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7951 7952 /* 7953 ** CAPI3REF: Virtual Table Configuration Options 7954 ** 7955 ** These macros define the various options to the 7956 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7957 ** can use to customize and optimize their behavior. 7958 ** 7959 ** <dl> 7960 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7961 ** <dd>Calls of the form 7962 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7963 ** where X is an integer. If X is zero, then the [virtual table] whose 7964 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7965 ** support constraints. In this configuration (which is the default) if 7966 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7967 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7968 ** specified as part of the users SQL statement, regardless of the actual 7969 ** ON CONFLICT mode specified. 7970 ** 7971 ** If X is non-zero, then the virtual table implementation guarantees 7972 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7973 ** any modifications to internal or persistent data structures have been made. 7974 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7975 ** is able to roll back a statement or database transaction, and abandon 7976 ** or continue processing the current SQL statement as appropriate. 7977 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7978 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7979 ** had been ABORT. 7980 ** 7981 ** Virtual table implementations that are required to handle OR REPLACE 7982 ** must do so within the [xUpdate] method. If a call to the 7983 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7984 ** CONFLICT policy is REPLACE, the virtual table implementation should 7985 ** silently replace the appropriate rows within the xUpdate callback and 7986 ** return SQLITE_OK. Or, if this is not possible, it may return 7987 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7988 ** constraint handling. 7989 ** </dl> 7990 */ 7991 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7992 7993 /* 7994 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7995 ** 7996 ** This function may only be called from within a call to the [xUpdate] method 7997 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7998 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7999 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8000 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8001 ** [virtual table]. 8002 */ 8003 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8004 8005 /* 8006 ** CAPI3REF: Conflict resolution modes 8007 ** KEYWORDS: {conflict resolution mode} 8008 ** 8009 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8010 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8011 ** is for the SQL statement being evaluated. 8012 ** 8013 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8014 ** return value from the [sqlite3_set_authorizer()] callback and that 8015 ** [SQLITE_ABORT] is also a [result code]. 8016 */ 8017 #define SQLITE_ROLLBACK 1 8018 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8019 #define SQLITE_FAIL 3 8020 /* #define SQLITE_ABORT 4 // Also an error code */ 8021 #define SQLITE_REPLACE 5 8022 8023 /* 8024 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8025 ** KEYWORDS: {scanstatus options} 8026 ** 8027 ** The following constants can be used for the T parameter to the 8028 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8029 ** different metric for sqlite3_stmt_scanstatus() to return. 8030 ** 8031 ** When the value returned to V is a string, space to hold that string is 8032 ** managed by the prepared statement S and will be automatically freed when 8033 ** S is finalized. 8034 ** 8035 ** <dl> 8036 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8037 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8038 ** set to the total number of times that the X-th loop has run.</dd> 8039 ** 8040 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8041 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8042 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8043 ** 8044 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8045 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8046 ** query planner's estimate for the average number of rows output from each 8047 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8048 ** then this value will approximate the quotient NVISIT/NLOOP and the 8049 ** product of this value for all prior loops with the same SELECTID will 8050 ** be the NLOOP value for the current loop. 8051 ** 8052 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8053 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8054 ** to a zero-terminated UTF-8 string containing the name of the index or table 8055 ** used for the X-th loop. 8056 ** 8057 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8058 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8059 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8060 ** description for the X-th loop. 8061 ** 8062 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8063 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8064 ** "select-id" for the X-th loop. The select-id identifies which query or 8065 ** subquery the loop is part of. The main query has a select-id of zero. 8066 ** The select-id is the same value as is output in the first column 8067 ** of an [EXPLAIN QUERY PLAN] query. 8068 ** </dl> 8069 */ 8070 #define SQLITE_SCANSTAT_NLOOP 0 8071 #define SQLITE_SCANSTAT_NVISIT 1 8072 #define SQLITE_SCANSTAT_EST 2 8073 #define SQLITE_SCANSTAT_NAME 3 8074 #define SQLITE_SCANSTAT_EXPLAIN 4 8075 #define SQLITE_SCANSTAT_SELECTID 5 8076 8077 /* 8078 ** CAPI3REF: Prepared Statement Scan Status 8079 ** METHOD: sqlite3_stmt 8080 ** 8081 ** This interface returns information about the predicted and measured 8082 ** performance for pStmt. Advanced applications can use this 8083 ** interface to compare the predicted and the measured performance and 8084 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8085 ** 8086 ** Since this interface is expected to be rarely used, it is only 8087 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8088 ** compile-time option. 8089 ** 8090 ** The "iScanStatusOp" parameter determines which status information to return. 8091 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8092 ** of this interface is undefined. 8093 ** ^The requested measurement is written into a variable pointed to by 8094 ** the "pOut" parameter. 8095 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8096 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8097 ** zero or greater than or equal to the total number of loops used to implement 8098 ** the statement - a non-zero value is returned and the variable that pOut 8099 ** points to is unchanged. 8100 ** 8101 ** ^Statistics might not be available for all loops in all statements. ^In cases 8102 ** where there exist loops with no available statistics, this function behaves 8103 ** as if the loop did not exist - it returns non-zero and leave the variable 8104 ** that pOut points to unchanged. 8105 ** 8106 ** See also: [sqlite3_stmt_scanstatus_reset()] 8107 */ 8108 SQLITE_API int sqlite3_stmt_scanstatus( 8109 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8110 int idx, /* Index of loop to report on */ 8111 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8112 void *pOut /* Result written here */ 8113 ); 8114 8115 /* 8116 ** CAPI3REF: Zero Scan-Status Counters 8117 ** METHOD: sqlite3_stmt 8118 ** 8119 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8120 ** 8121 ** This API is only available if the library is built with pre-processor 8122 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8123 */ 8124 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8125 8126 /* 8127 ** CAPI3REF: Flush caches to disk mid-transaction 8128 ** 8129 ** ^If a write-transaction is open on [database connection] D when the 8130 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8131 ** pages in the pager-cache that are not currently in use are written out 8132 ** to disk. A dirty page may be in use if a database cursor created by an 8133 ** active SQL statement is reading from it, or if it is page 1 of a database 8134 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8135 ** interface flushes caches for all schemas - "main", "temp", and 8136 ** any [attached] databases. 8137 ** 8138 ** ^If this function needs to obtain extra database locks before dirty pages 8139 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8140 ** immediately and there is a busy-handler callback configured, it is invoked 8141 ** in the usual manner. ^If the required lock still cannot be obtained, then 8142 ** the database is skipped and an attempt made to flush any dirty pages 8143 ** belonging to the next (if any) database. ^If any databases are skipped 8144 ** because locks cannot be obtained, but no other error occurs, this 8145 ** function returns SQLITE_BUSY. 8146 ** 8147 ** ^If any other error occurs while flushing dirty pages to disk (for 8148 ** example an IO error or out-of-memory condition), then processing is 8149 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8150 ** 8151 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8152 ** 8153 ** ^This function does not set the database handle error code or message 8154 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8155 */ 8156 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8157 8158 /* 8159 ** CAPI3REF: The pre-update hook. 8160 ** 8161 ** ^These interfaces are only available if SQLite is compiled using the 8162 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8163 ** 8164 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8165 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8166 ** on a [rowid table]. 8167 ** ^At most one preupdate hook may be registered at a time on a single 8168 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8169 ** the previous setting. 8170 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8171 ** with a NULL pointer as the second parameter. 8172 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8173 ** the first parameter to callbacks. 8174 ** 8175 ** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate 8176 ** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID] 8177 ** tables. 8178 ** 8179 ** ^The second parameter to the preupdate callback is a pointer to 8180 ** the [database connection] that registered the preupdate hook. 8181 ** ^The third parameter to the preupdate callback is one of the constants 8182 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8183 ** kind of update operation that is about to occur. 8184 ** ^(The fourth parameter to the preupdate callback is the name of the 8185 ** database within the database connection that is being modified. This 8186 ** will be "main" for the main database or "temp" for TEMP tables or 8187 ** the name given after the AS keyword in the [ATTACH] statement for attached 8188 ** databases.)^ 8189 ** ^The fifth parameter to the preupdate callback is the name of the 8190 ** table that is being modified. 8191 ** ^The sixth parameter to the preupdate callback is the initial [rowid] of the 8192 ** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is 8193 ** undefined for SQLITE_INSERT changes. 8194 ** ^The seventh parameter to the preupdate callback is the final [rowid] of 8195 ** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is 8196 ** undefined for SQLITE_DELETE changes. 8197 ** 8198 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8199 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8200 ** provide additional information about a preupdate event. These routines 8201 ** may only be called from within a preupdate callback. Invoking any of 8202 ** these routines from outside of a preupdate callback or with a 8203 ** [database connection] pointer that is different from the one supplied 8204 ** to the preupdate callback results in undefined and probably undesirable 8205 ** behavior. 8206 ** 8207 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8208 ** in the row that is being inserted, updated, or deleted. 8209 ** 8210 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8211 ** a [protected sqlite3_value] that contains the value of the Nth column of 8212 ** the table row before it is updated. The N parameter must be between 0 8213 ** and one less than the number of columns or the behavior will be 8214 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8215 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8216 ** behavior is undefined. The [sqlite3_value] that P points to 8217 ** will be destroyed when the preupdate callback returns. 8218 ** 8219 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8220 ** a [protected sqlite3_value] that contains the value of the Nth column of 8221 ** the table row after it is updated. The N parameter must be between 0 8222 ** and one less than the number of columns or the behavior will be 8223 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8224 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8225 ** behavior is undefined. The [sqlite3_value] that P points to 8226 ** will be destroyed when the preupdate callback returns. 8227 ** 8228 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8229 ** callback was invoked as a result of a direct insert, update, or delete 8230 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8231 ** triggers; or 2 for changes resulting from triggers called by top-level 8232 ** triggers; and so forth. 8233 ** 8234 ** See also: [sqlite3_update_hook()] 8235 */ 8236 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8237 SQLITE_API void *sqlite3_preupdate_hook( 8238 sqlite3 *db, 8239 void(*xPreUpdate)( 8240 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8241 sqlite3 *db, /* Database handle */ 8242 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8243 char const *zDb, /* Database name */ 8244 char const *zName, /* Table name */ 8245 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8246 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8247 ), 8248 void* 8249 ); 8250 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8251 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8252 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8253 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8254 #endif 8255 8256 /* 8257 ** CAPI3REF: Low-level system error code 8258 ** 8259 ** ^Attempt to return the underlying operating system error code or error 8260 ** number that caused the most recent I/O error or failure to open a file. 8261 ** The return value is OS-dependent. For example, on unix systems, after 8262 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8263 ** called to get back the underlying "errno" that caused the problem, such 8264 ** as ENOSPC, EAUTH, EISDIR, and so forth. 8265 */ 8266 SQLITE_API int sqlite3_system_errno(sqlite3*); 8267 8268 /* 8269 ** CAPI3REF: Database Snapshot 8270 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 8271 ** EXPERIMENTAL 8272 ** 8273 ** An instance of the snapshot object records the state of a [WAL mode] 8274 ** database for some specific point in history. 8275 ** 8276 ** In [WAL mode], multiple [database connections] that are open on the 8277 ** same database file can each be reading a different historical version 8278 ** of the database file. When a [database connection] begins a read 8279 ** transaction, that connection sees an unchanging copy of the database 8280 ** as it existed for the point in time when the transaction first started. 8281 ** Subsequent changes to the database from other connections are not seen 8282 ** by the reader until a new read transaction is started. 8283 ** 8284 ** The sqlite3_snapshot object records state information about an historical 8285 ** version of the database file so that it is possible to later open a new read 8286 ** transaction that sees that historical version of the database rather than 8287 ** the most recent version. 8288 ** 8289 ** The constructor for this object is [sqlite3_snapshot_get()]. The 8290 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8291 ** to an historical snapshot (if possible). The destructor for 8292 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8293 */ 8294 typedef struct sqlite3_snapshot { 8295 unsigned char hidden[48]; 8296 } sqlite3_snapshot; 8297 8298 /* 8299 ** CAPI3REF: Record A Database Snapshot 8300 ** EXPERIMENTAL 8301 ** 8302 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8303 ** new [sqlite3_snapshot] object that records the current state of 8304 ** schema S in database connection D. ^On success, the 8305 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8306 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8307 ** If there is not already a read-transaction open on schema S when 8308 ** this function is called, one is opened automatically. 8309 ** 8310 ** The following must be true for this function to succeed. If any of 8311 ** the following statements are false when sqlite3_snapshot_get() is 8312 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 8313 ** in this case. 8314 ** 8315 ** <ul> 8316 ** <li> The database handle must be in [autocommit mode]. 8317 ** 8318 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 8319 ** 8320 ** <li> There must not be a write transaction open on schema S of database 8321 ** connection D. 8322 ** 8323 ** <li> One or more transactions must have been written to the current wal 8324 ** file since it was created on disk (by any connection). This means 8325 ** that a snapshot cannot be taken on a wal mode database with no wal 8326 ** file immediately after it is first opened. At least one transaction 8327 ** must be written to it first. 8328 ** </ul> 8329 ** 8330 ** This function may also return SQLITE_NOMEM. If it is called with the 8331 ** database handle in autocommit mode but fails for some other reason, 8332 ** whether or not a read transaction is opened on schema S is undefined. 8333 ** 8334 ** The [sqlite3_snapshot] object returned from a successful call to 8335 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8336 ** to avoid a memory leak. 8337 ** 8338 ** The [sqlite3_snapshot_get()] interface is only available when the 8339 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8340 */ 8341 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8342 sqlite3 *db, 8343 const char *zSchema, 8344 sqlite3_snapshot **ppSnapshot 8345 ); 8346 8347 /* 8348 ** CAPI3REF: Start a read transaction on an historical snapshot 8349 ** EXPERIMENTAL 8350 ** 8351 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8352 ** read transaction for schema S of 8353 ** [database connection] D such that the read transaction 8354 ** refers to historical [snapshot] P, rather than the most 8355 ** recent change to the database. 8356 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8357 ** or an appropriate [error code] if it fails. 8358 ** 8359 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8360 ** the first operation following the [BEGIN] that takes the schema S 8361 ** out of [autocommit mode]. 8362 ** ^In other words, schema S must not currently be in 8363 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8364 ** database connection D must be out of [autocommit mode]. 8365 ** ^A [snapshot] will fail to open if it has been overwritten by a 8366 ** [checkpoint]. 8367 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8368 ** database connection D does not know that the database file for 8369 ** schema S is in [WAL mode]. A database connection might not know 8370 ** that the database file is in [WAL mode] if there has been no prior 8371 ** I/O on that database connection, or if the database entered [WAL mode] 8372 ** after the most recent I/O on the database connection.)^ 8373 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 8374 ** database connection in order to make it ready to use snapshots.) 8375 ** 8376 ** The [sqlite3_snapshot_open()] interface is only available when the 8377 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8378 */ 8379 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8380 sqlite3 *db, 8381 const char *zSchema, 8382 sqlite3_snapshot *pSnapshot 8383 ); 8384 8385 /* 8386 ** CAPI3REF: Destroy a snapshot 8387 ** EXPERIMENTAL 8388 ** 8389 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8390 ** The application must eventually free every [sqlite3_snapshot] object 8391 ** using this routine to avoid a memory leak. 8392 ** 8393 ** The [sqlite3_snapshot_free()] interface is only available when the 8394 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8395 */ 8396 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8397 8398 /* 8399 ** CAPI3REF: Compare the ages of two snapshot handles. 8400 ** EXPERIMENTAL 8401 ** 8402 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8403 ** of two valid snapshot handles. 8404 ** 8405 ** If the two snapshot handles are not associated with the same database 8406 ** file, the result of the comparison is undefined. 8407 ** 8408 ** Additionally, the result of the comparison is only valid if both of the 8409 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8410 ** last time the wal file was deleted. The wal file is deleted when the 8411 ** database is changed back to rollback mode or when the number of database 8412 ** clients drops to zero. If either snapshot handle was obtained before the 8413 ** wal file was last deleted, the value returned by this function 8414 ** is undefined. 8415 ** 8416 ** Otherwise, this API returns a negative value if P1 refers to an older 8417 ** snapshot than P2, zero if the two handles refer to the same database 8418 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 8419 */ 8420 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8421 sqlite3_snapshot *p1, 8422 sqlite3_snapshot *p2 8423 ); 8424 8425 /* 8426 ** CAPI3REF: Recover snapshots from a wal file 8427 ** EXPERIMENTAL 8428 ** 8429 ** If all connections disconnect from a database file but do not perform 8430 ** a checkpoint, the existing wal file is opened along with the database 8431 ** file the next time the database is opened. At this point it is only 8432 ** possible to successfully call sqlite3_snapshot_open() to open the most 8433 ** recent snapshot of the database (the one at the head of the wal file), 8434 ** even though the wal file may contain other valid snapshots for which 8435 ** clients have sqlite3_snapshot handles. 8436 ** 8437 ** This function attempts to scan the wal file associated with database zDb 8438 ** of database handle db and make all valid snapshots available to 8439 ** sqlite3_snapshot_open(). It is an error if there is already a read 8440 ** transaction open on the database, or if the database is not a wal mode 8441 ** database. 8442 ** 8443 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8444 */ 8445 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8446 8447 /* 8448 ** Undo the hack that converts floating point types to integer for 8449 ** builds on processors without floating point support. 8450 */ 8451 #ifdef SQLITE_OMIT_FLOATING_POINT 8452 # undef double 8453 #endif 8454 8455 #ifdef __cplusplus 8456 } /* End of the 'extern "C"' block */ 8457 #endif 8458 #endif /* SQLITE3_H */ 8459 8460 /******** Begin file sqlite3rtree.h *********/ 8461 /* 8462 ** 2010 August 30 8463 ** 8464 ** The author disclaims copyright to this source code. In place of 8465 ** a legal notice, here is a blessing: 8466 ** 8467 ** May you do good and not evil. 8468 ** May you find forgiveness for yourself and forgive others. 8469 ** May you share freely, never taking more than you give. 8470 ** 8471 ************************************************************************* 8472 */ 8473 8474 #ifndef _SQLITE3RTREE_H_ 8475 #define _SQLITE3RTREE_H_ 8476 8477 8478 #ifdef __cplusplus 8479 extern "C" { 8480 #endif 8481 8482 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8483 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8484 8485 /* The double-precision datatype used by RTree depends on the 8486 ** SQLITE_RTREE_INT_ONLY compile-time option. 8487 */ 8488 #ifdef SQLITE_RTREE_INT_ONLY 8489 typedef sqlite3_int64 sqlite3_rtree_dbl; 8490 #else 8491 typedef double sqlite3_rtree_dbl; 8492 #endif 8493 8494 /* 8495 ** Register a geometry callback named zGeom that can be used as part of an 8496 ** R-Tree geometry query as follows: 8497 ** 8498 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8499 */ 8500 SQLITE_API int sqlite3_rtree_geometry_callback( 8501 sqlite3 *db, 8502 const char *zGeom, 8503 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8504 void *pContext 8505 ); 8506 8507 8508 /* 8509 ** A pointer to a structure of the following type is passed as the first 8510 ** argument to callbacks registered using rtree_geometry_callback(). 8511 */ 8512 struct sqlite3_rtree_geometry { 8513 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8514 int nParam; /* Size of array aParam[] */ 8515 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8516 void *pUser; /* Callback implementation user data */ 8517 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8518 }; 8519 8520 /* 8521 ** Register a 2nd-generation geometry callback named zScore that can be 8522 ** used as part of an R-Tree geometry query as follows: 8523 ** 8524 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8525 */ 8526 SQLITE_API int sqlite3_rtree_query_callback( 8527 sqlite3 *db, 8528 const char *zQueryFunc, 8529 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8530 void *pContext, 8531 void (*xDestructor)(void*) 8532 ); 8533 8534 8535 /* 8536 ** A pointer to a structure of the following type is passed as the 8537 ** argument to scored geometry callback registered using 8538 ** sqlite3_rtree_query_callback(). 8539 ** 8540 ** Note that the first 5 fields of this structure are identical to 8541 ** sqlite3_rtree_geometry. This structure is a subclass of 8542 ** sqlite3_rtree_geometry. 8543 */ 8544 struct sqlite3_rtree_query_info { 8545 void *pContext; /* pContext from when function registered */ 8546 int nParam; /* Number of function parameters */ 8547 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8548 void *pUser; /* callback can use this, if desired */ 8549 void (*xDelUser)(void*); /* function to free pUser */ 8550 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8551 unsigned int *anQueue; /* Number of pending entries in the queue */ 8552 int nCoord; /* Number of coordinates */ 8553 int iLevel; /* Level of current node or entry */ 8554 int mxLevel; /* The largest iLevel value in the tree */ 8555 sqlite3_int64 iRowid; /* Rowid for current entry */ 8556 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8557 int eParentWithin; /* Visibility of parent node */ 8558 int eWithin; /* OUT: Visiblity */ 8559 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8560 /* The following fields are only available in 3.8.11 and later */ 8561 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8562 }; 8563 8564 /* 8565 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8566 */ 8567 #define NOT_WITHIN 0 /* Object completely outside of query region */ 8568 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8569 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8570 8571 8572 #ifdef __cplusplus 8573 } /* end of the 'extern "C"' block */ 8574 #endif 8575 8576 #endif /* ifndef _SQLITE3RTREE_H_ */ 8577 8578 /******** End of sqlite3rtree.h *********/ 8579 /******** Begin file sqlite3session.h *********/ 8580 8581 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8582 #define __SQLITESESSION_H_ 1 8583 8584 /* 8585 ** Make sure we can call this stuff from C++. 8586 */ 8587 #ifdef __cplusplus 8588 extern "C" { 8589 #endif 8590 8591 8592 /* 8593 ** CAPI3REF: Session Object Handle 8594 */ 8595 typedef struct sqlite3_session sqlite3_session; 8596 8597 /* 8598 ** CAPI3REF: Changeset Iterator Handle 8599 */ 8600 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8601 8602 /* 8603 ** CAPI3REF: Create A New Session Object 8604 ** 8605 ** Create a new session object attached to database handle db. If successful, 8606 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 8607 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8608 ** error code (e.g. SQLITE_NOMEM) is returned. 8609 ** 8610 ** It is possible to create multiple session objects attached to a single 8611 ** database handle. 8612 ** 8613 ** Session objects created using this function should be deleted using the 8614 ** [sqlite3session_delete()] function before the database handle that they 8615 ** are attached to is itself closed. If the database handle is closed before 8616 ** the session object is deleted, then the results of calling any session 8617 ** module function, including [sqlite3session_delete()] on the session object 8618 ** are undefined. 8619 ** 8620 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8621 ** is not possible for an application to register a pre-update hook on a 8622 ** database handle that has one or more session objects attached. Nor is 8623 ** it possible to create a session object attached to a database handle for 8624 ** which a pre-update hook is already defined. The results of attempting 8625 ** either of these things are undefined. 8626 ** 8627 ** The session object will be used to create changesets for tables in 8628 ** database zDb, where zDb is either "main", or "temp", or the name of an 8629 ** attached database. It is not an error if database zDb is not attached 8630 ** to the database when the session object is created. 8631 */ 8632 int sqlite3session_create( 8633 sqlite3 *db, /* Database handle */ 8634 const char *zDb, /* Name of db (e.g. "main") */ 8635 sqlite3_session **ppSession /* OUT: New session object */ 8636 ); 8637 8638 /* 8639 ** CAPI3REF: Delete A Session Object 8640 ** 8641 ** Delete a session object previously allocated using 8642 ** [sqlite3session_create()]. Once a session object has been deleted, the 8643 ** results of attempting to use pSession with any other session module 8644 ** function are undefined. 8645 ** 8646 ** Session objects must be deleted before the database handle to which they 8647 ** are attached is closed. Refer to the documentation for 8648 ** [sqlite3session_create()] for details. 8649 */ 8650 void sqlite3session_delete(sqlite3_session *pSession); 8651 8652 8653 /* 8654 ** CAPI3REF: Enable Or Disable A Session Object 8655 ** 8656 ** Enable or disable the recording of changes by a session object. When 8657 ** enabled, a session object records changes made to the database. When 8658 ** disabled - it does not. A newly created session object is enabled. 8659 ** Refer to the documentation for [sqlite3session_changeset()] for further 8660 ** details regarding how enabling and disabling a session object affects 8661 ** the eventual changesets. 8662 ** 8663 ** Passing zero to this function disables the session. Passing a value 8664 ** greater than zero enables it. Passing a value less than zero is a 8665 ** no-op, and may be used to query the current state of the session. 8666 ** 8667 ** The return value indicates the final state of the session object: 0 if 8668 ** the session is disabled, or 1 if it is enabled. 8669 */ 8670 int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8671 8672 /* 8673 ** CAPI3REF: Set Or Clear the Indirect Change Flag 8674 ** 8675 ** Each change recorded by a session object is marked as either direct or 8676 ** indirect. A change is marked as indirect if either: 8677 ** 8678 ** <ul> 8679 ** <li> The session object "indirect" flag is set when the change is 8680 ** made, or 8681 ** <li> The change is made by an SQL trigger or foreign key action 8682 ** instead of directly as a result of a users SQL statement. 8683 ** </ul> 8684 ** 8685 ** If a single row is affected by more than one operation within a session, 8686 ** then the change is considered indirect if all operations meet the criteria 8687 ** for an indirect change above, or direct otherwise. 8688 ** 8689 ** This function is used to set, clear or query the session object indirect 8690 ** flag. If the second argument passed to this function is zero, then the 8691 ** indirect flag is cleared. If it is greater than zero, the indirect flag 8692 ** is set. Passing a value less than zero does not modify the current value 8693 ** of the indirect flag, and may be used to query the current state of the 8694 ** indirect flag for the specified session object. 8695 ** 8696 ** The return value indicates the final state of the indirect flag: 0 if 8697 ** it is clear, or 1 if it is set. 8698 */ 8699 int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8700 8701 /* 8702 ** CAPI3REF: Attach A Table To A Session Object 8703 ** 8704 ** If argument zTab is not NULL, then it is the name of a table to attach 8705 ** to the session object passed as the first argument. All subsequent changes 8706 ** made to the table while the session object is enabled will be recorded. See 8707 ** documentation for [sqlite3session_changeset()] for further details. 8708 ** 8709 ** Or, if argument zTab is NULL, then changes are recorded for all tables 8710 ** in the database. If additional tables are added to the database (by 8711 ** executing "CREATE TABLE" statements) after this call is made, changes for 8712 ** the new tables are also recorded. 8713 ** 8714 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8715 ** defined as part of their CREATE TABLE statement. It does not matter if the 8716 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8717 ** KEY may consist of a single column, or may be a composite key. 8718 ** 8719 ** It is not an error if the named table does not exist in the database. Nor 8720 ** is it an error if the named table does not have a PRIMARY KEY. However, 8721 ** no changes will be recorded in either of these scenarios. 8722 ** 8723 ** Changes are not recorded for individual rows that have NULL values stored 8724 ** in one or more of their PRIMARY KEY columns. 8725 ** 8726 ** SQLITE_OK is returned if the call completes without error. Or, if an error 8727 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8728 */ 8729 int sqlite3session_attach( 8730 sqlite3_session *pSession, /* Session object */ 8731 const char *zTab /* Table name */ 8732 ); 8733 8734 /* 8735 ** CAPI3REF: Set a table filter on a Session Object. 8736 ** 8737 ** The second argument (xFilter) is the "filter callback". For changes to rows 8738 ** in tables that are not attached to the Session object, the filter is called 8739 ** to determine whether changes to the table's rows should be tracked or not. 8740 ** If xFilter returns 0, changes is not tracked. Note that once a table is 8741 ** attached, xFilter will not be called again. 8742 */ 8743 void sqlite3session_table_filter( 8744 sqlite3_session *pSession, /* Session object */ 8745 int(*xFilter)( 8746 void *pCtx, /* Copy of third arg to _filter_table() */ 8747 const char *zTab /* Table name */ 8748 ), 8749 void *pCtx /* First argument passed to xFilter */ 8750 ); 8751 8752 /* 8753 ** CAPI3REF: Generate A Changeset From A Session Object 8754 ** 8755 ** Obtain a changeset containing changes to the tables attached to the 8756 ** session object passed as the first argument. If successful, 8757 ** set *ppChangeset to point to a buffer containing the changeset 8758 ** and *pnChangeset to the size of the changeset in bytes before returning 8759 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8760 ** zero and return an SQLite error code. 8761 ** 8762 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8763 ** each representing a change to a single row of an attached table. An INSERT 8764 ** change contains the values of each field of a new database row. A DELETE 8765 ** contains the original values of each field of a deleted database row. An 8766 ** UPDATE change contains the original values of each field of an updated 8767 ** database row along with the updated values for each updated non-primary-key 8768 ** column. It is not possible for an UPDATE change to represent a change that 8769 ** modifies the values of primary key columns. If such a change is made, it 8770 ** is represented in a changeset as a DELETE followed by an INSERT. 8771 ** 8772 ** Changes are not recorded for rows that have NULL values stored in one or 8773 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8774 ** no corresponding change is present in the changesets returned by this 8775 ** function. If an existing row with one or more NULL values stored in 8776 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8777 ** only an INSERT is appears in the changeset. Similarly, if an existing row 8778 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 8779 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8780 ** DELETE change only. 8781 ** 8782 ** The contents of a changeset may be traversed using an iterator created 8783 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 8784 ** a database with a compatible schema using the [sqlite3changeset_apply()] 8785 ** API. 8786 ** 8787 ** Within a changeset generated by this function, all changes related to a 8788 ** single table are grouped together. In other words, when iterating through 8789 ** a changeset or when applying a changeset to a database, all changes related 8790 ** to a single table are processed before moving on to the next table. Tables 8791 ** are sorted in the same order in which they were attached (or auto-attached) 8792 ** to the sqlite3_session object. The order in which the changes related to 8793 ** a single table are stored is undefined. 8794 ** 8795 ** Following a successful call to this function, it is the responsibility of 8796 ** the caller to eventually free the buffer that *ppChangeset points to using 8797 ** [sqlite3_free()]. 8798 ** 8799 ** <h3>Changeset Generation</h3> 8800 ** 8801 ** Once a table has been attached to a session object, the session object 8802 ** records the primary key values of all new rows inserted into the table. 8803 ** It also records the original primary key and other column values of any 8804 ** deleted or updated rows. For each unique primary key value, data is only 8805 ** recorded once - the first time a row with said primary key is inserted, 8806 ** updated or deleted in the lifetime of the session. 8807 ** 8808 ** There is one exception to the previous paragraph: when a row is inserted, 8809 ** updated or deleted, if one or more of its primary key columns contain a 8810 ** NULL value, no record of the change is made. 8811 ** 8812 ** The session object therefore accumulates two types of records - those 8813 ** that consist of primary key values only (created when the user inserts 8814 ** a new record) and those that consist of the primary key values and the 8815 ** original values of other table columns (created when the users deletes 8816 ** or updates a record). 8817 ** 8818 ** When this function is called, the requested changeset is created using 8819 ** both the accumulated records and the current contents of the database 8820 ** file. Specifically: 8821 ** 8822 ** <ul> 8823 ** <li> For each record generated by an insert, the database is queried 8824 ** for a row with a matching primary key. If one is found, an INSERT 8825 ** change is added to the changeset. If no such row is found, no change 8826 ** is added to the changeset. 8827 ** 8828 ** <li> For each record generated by an update or delete, the database is 8829 ** queried for a row with a matching primary key. If such a row is 8830 ** found and one or more of the non-primary key fields have been 8831 ** modified from their original values, an UPDATE change is added to 8832 ** the changeset. Or, if no such row is found in the table, a DELETE 8833 ** change is added to the changeset. If there is a row with a matching 8834 ** primary key in the database, but all fields contain their original 8835 ** values, no change is added to the changeset. 8836 ** </ul> 8837 ** 8838 ** This means, amongst other things, that if a row is inserted and then later 8839 ** deleted while a session object is active, neither the insert nor the delete 8840 ** will be present in the changeset. Or if a row is deleted and then later a 8841 ** row with the same primary key values inserted while a session object is 8842 ** active, the resulting changeset will contain an UPDATE change instead of 8843 ** a DELETE and an INSERT. 8844 ** 8845 ** When a session object is disabled (see the [sqlite3session_enable()] API), 8846 ** it does not accumulate records when rows are inserted, updated or deleted. 8847 ** This may appear to have some counter-intuitive effects if a single row 8848 ** is written to more than once during a session. For example, if a row 8849 ** is inserted while a session object is enabled, then later deleted while 8850 ** the same session object is disabled, no INSERT record will appear in the 8851 ** changeset, even though the delete took place while the session was disabled. 8852 ** Or, if one field of a row is updated while a session is disabled, and 8853 ** another field of the same row is updated while the session is enabled, the 8854 ** resulting changeset will contain an UPDATE change that updates both fields. 8855 */ 8856 int sqlite3session_changeset( 8857 sqlite3_session *pSession, /* Session object */ 8858 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8859 void **ppChangeset /* OUT: Buffer containing changeset */ 8860 ); 8861 8862 /* 8863 ** CAPI3REF: Load The Difference Between Tables Into A Session 8864 ** 8865 ** If it is not already attached to the session object passed as the first 8866 ** argument, this function attaches table zTbl in the same manner as the 8867 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8868 ** does not have a primary key, this function is a no-op (but does not return 8869 ** an error). 8870 ** 8871 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8872 ** attached to the same database handle as the session object that contains 8873 ** a table compatible with the table attached to the session by this function. 8874 ** A table is considered compatible if it: 8875 ** 8876 ** <ul> 8877 ** <li> Has the same name, 8878 ** <li> Has the same set of columns declared in the same order, and 8879 ** <li> Has the same PRIMARY KEY definition. 8880 ** </ul> 8881 ** 8882 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8883 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 8884 ** but no changes are added to the session object. As with other session 8885 ** APIs, tables without PRIMARY KEYs are simply ignored. 8886 ** 8887 ** This function adds a set of changes to the session object that could be 8888 ** used to update the table in database zFrom (call this the "from-table") 8889 ** so that its content is the same as the table attached to the session 8890 ** object (call this the "to-table"). Specifically: 8891 ** 8892 ** <ul> 8893 ** <li> For each row (primary key) that exists in the to-table but not in 8894 ** the from-table, an INSERT record is added to the session object. 8895 ** 8896 ** <li> For each row (primary key) that exists in the to-table but not in 8897 ** the from-table, a DELETE record is added to the session object. 8898 ** 8899 ** <li> For each row (primary key) that exists in both tables, but features 8900 ** different in each, an UPDATE record is added to the session. 8901 ** </ul> 8902 ** 8903 ** To clarify, if this function is called and then a changeset constructed 8904 ** using [sqlite3session_changeset()], then after applying that changeset to 8905 ** database zFrom the contents of the two compatible tables would be 8906 ** identical. 8907 ** 8908 ** It an error if database zFrom does not exist or does not contain the 8909 ** required compatible table. 8910 ** 8911 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 8912 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 8913 ** may be set to point to a buffer containing an English language error 8914 ** message. It is the responsibility of the caller to free this buffer using 8915 ** sqlite3_free(). 8916 */ 8917 int sqlite3session_diff( 8918 sqlite3_session *pSession, 8919 const char *zFromDb, 8920 const char *zTbl, 8921 char **pzErrMsg 8922 ); 8923 8924 8925 /* 8926 ** CAPI3REF: Generate A Patchset From A Session Object 8927 ** 8928 ** The differences between a patchset and a changeset are that: 8929 ** 8930 ** <ul> 8931 ** <li> DELETE records consist of the primary key fields only. The 8932 ** original values of other fields are omitted. 8933 ** <li> The original values of any modified fields are omitted from 8934 ** UPDATE records. 8935 ** </ul> 8936 ** 8937 ** A patchset blob may be used with up to date versions of all 8938 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 8939 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 8940 ** attempting to use a patchset blob with old versions of the 8941 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 8942 ** 8943 ** Because the non-primary key "old.*" fields are omitted, no 8944 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 8945 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 8946 ** in the same way as for changesets. 8947 ** 8948 ** Changes within a patchset are ordered in the same way as for changesets 8949 ** generated by the sqlite3session_changeset() function (i.e. all changes for 8950 ** a single table are grouped together, tables appear in the order in which 8951 ** they were attached to the session object). 8952 */ 8953 int sqlite3session_patchset( 8954 sqlite3_session *pSession, /* Session object */ 8955 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 8956 void **ppPatchset /* OUT: Buffer containing changeset */ 8957 ); 8958 8959 /* 8960 ** CAPI3REF: Test if a changeset has recorded any changes. 8961 ** 8962 ** Return non-zero if no changes to attached tables have been recorded by 8963 ** the session object passed as the first argument. Otherwise, if one or 8964 ** more changes have been recorded, return zero. 8965 ** 8966 ** Even if this function returns zero, it is possible that calling 8967 ** [sqlite3session_changeset()] on the session handle may still return a 8968 ** changeset that contains no changes. This can happen when a row in 8969 ** an attached table is modified and then later on the original values 8970 ** are restored. However, if this function returns non-zero, then it is 8971 ** guaranteed that a call to sqlite3session_changeset() will return a 8972 ** changeset containing zero changes. 8973 */ 8974 int sqlite3session_isempty(sqlite3_session *pSession); 8975 8976 /* 8977 ** CAPI3REF: Create An Iterator To Traverse A Changeset 8978 ** 8979 ** Create an iterator used to iterate through the contents of a changeset. 8980 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 8981 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 8982 ** SQLite error code is returned. 8983 ** 8984 ** The following functions can be used to advance and query a changeset 8985 ** iterator created by this function: 8986 ** 8987 ** <ul> 8988 ** <li> [sqlite3changeset_next()] 8989 ** <li> [sqlite3changeset_op()] 8990 ** <li> [sqlite3changeset_new()] 8991 ** <li> [sqlite3changeset_old()] 8992 ** </ul> 8993 ** 8994 ** It is the responsibility of the caller to eventually destroy the iterator 8995 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 8996 ** changeset (pChangeset) must remain valid until after the iterator is 8997 ** destroyed. 8998 ** 8999 ** Assuming the changeset blob was created by one of the 9000 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9001 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9002 ** that apply to a single table are grouped together. This means that when 9003 ** an application iterates through a changeset using an iterator created by 9004 ** this function, all changes that relate to a single table are visited 9005 ** consecutively. There is no chance that the iterator will visit a change 9006 ** the applies to table X, then one for table Y, and then later on visit 9007 ** another change for table X. 9008 */ 9009 int sqlite3changeset_start( 9010 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9011 int nChangeset, /* Size of changeset blob in bytes */ 9012 void *pChangeset /* Pointer to blob containing changeset */ 9013 ); 9014 9015 9016 /* 9017 ** CAPI3REF: Advance A Changeset Iterator 9018 ** 9019 ** This function may only be used with iterators created by function 9020 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 9021 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9022 ** is returned and the call has no effect. 9023 ** 9024 ** Immediately after an iterator is created by sqlite3changeset_start(), it 9025 ** does not point to any change in the changeset. Assuming the changeset 9026 ** is not empty, the first call to this function advances the iterator to 9027 ** point to the first change in the changeset. Each subsequent call advances 9028 ** the iterator to point to the next change in the changeset (if any). If 9029 ** no error occurs and the iterator points to a valid change after a call 9030 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9031 ** Otherwise, if all changes in the changeset have already been visited, 9032 ** SQLITE_DONE is returned. 9033 ** 9034 ** If an error occurs, an SQLite error code is returned. Possible error 9035 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9036 ** SQLITE_NOMEM. 9037 */ 9038 int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9039 9040 /* 9041 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9042 ** 9043 ** The pIter argument passed to this function may either be an iterator 9044 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9045 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9046 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9047 ** is not the case, this function returns [SQLITE_MISUSE]. 9048 ** 9049 ** If argument pzTab is not NULL, then *pzTab is set to point to a 9050 ** nul-terminated utf-8 encoded string containing the name of the table 9051 ** affected by the current change. The buffer remains valid until either 9052 ** sqlite3changeset_next() is called on the iterator or until the 9053 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9054 ** set to the number of columns in the table affected by the change. If 9055 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9056 ** is an indirect change, or false (0) otherwise. See the documentation for 9057 ** [sqlite3session_indirect()] for a description of direct and indirect 9058 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9059 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9060 ** type of change that the iterator currently points to. 9061 ** 9062 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9063 ** SQLite error code is returned. The values of the output variables may not 9064 ** be trusted in this case. 9065 */ 9066 int sqlite3changeset_op( 9067 sqlite3_changeset_iter *pIter, /* Iterator object */ 9068 const char **pzTab, /* OUT: Pointer to table name */ 9069 int *pnCol, /* OUT: Number of columns in table */ 9070 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9071 int *pbIndirect /* OUT: True for an 'indirect' change */ 9072 ); 9073 9074 /* 9075 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 9076 ** 9077 ** For each modified table, a changeset includes the following: 9078 ** 9079 ** <ul> 9080 ** <li> The number of columns in the table, and 9081 ** <li> Which of those columns make up the tables PRIMARY KEY. 9082 ** </ul> 9083 ** 9084 ** This function is used to find which columns comprise the PRIMARY KEY of 9085 ** the table modified by the change that iterator pIter currently points to. 9086 ** If successful, *pabPK is set to point to an array of nCol entries, where 9087 ** nCol is the number of columns in the table. Elements of *pabPK are set to 9088 ** 0x01 if the corresponding column is part of the tables primary key, or 9089 ** 0x00 if it is not. 9090 ** 9091 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9092 ** in the table. 9093 ** 9094 ** If this function is called when the iterator does not point to a valid 9095 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9096 ** SQLITE_OK is returned and the output variables populated as described 9097 ** above. 9098 */ 9099 int sqlite3changeset_pk( 9100 sqlite3_changeset_iter *pIter, /* Iterator object */ 9101 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9102 int *pnCol /* OUT: Number of entries in output array */ 9103 ); 9104 9105 /* 9106 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9107 ** 9108 ** The pIter argument passed to this function may either be an iterator 9109 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9110 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9111 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9112 ** Furthermore, it may only be called if the type of change that the iterator 9113 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9114 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9115 ** 9116 ** Argument iVal must be greater than or equal to 0, and less than the number 9117 ** of columns in the table affected by the current change. Otherwise, 9118 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9119 ** 9120 ** If successful, this function sets *ppValue to point to a protected 9121 ** sqlite3_value object containing the iVal'th value from the vector of 9122 ** original row values stored as part of the UPDATE or DELETE change and 9123 ** returns SQLITE_OK. The name of the function comes from the fact that this 9124 ** is similar to the "old.*" columns available to update or delete triggers. 9125 ** 9126 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9127 ** is returned and *ppValue is set to NULL. 9128 */ 9129 int sqlite3changeset_old( 9130 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9131 int iVal, /* Column number */ 9132 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9133 ); 9134 9135 /* 9136 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9137 ** 9138 ** The pIter argument passed to this function may either be an iterator 9139 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9140 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9141 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9142 ** Furthermore, it may only be called if the type of change that the iterator 9143 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9144 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9145 ** 9146 ** Argument iVal must be greater than or equal to 0, and less than the number 9147 ** of columns in the table affected by the current change. Otherwise, 9148 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9149 ** 9150 ** If successful, this function sets *ppValue to point to a protected 9151 ** sqlite3_value object containing the iVal'th value from the vector of 9152 ** new row values stored as part of the UPDATE or INSERT change and 9153 ** returns SQLITE_OK. If the change is an UPDATE and does not include 9154 ** a new value for the requested column, *ppValue is set to NULL and 9155 ** SQLITE_OK returned. The name of the function comes from the fact that 9156 ** this is similar to the "new.*" columns available to update or delete 9157 ** triggers. 9158 ** 9159 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9160 ** is returned and *ppValue is set to NULL. 9161 */ 9162 int sqlite3changeset_new( 9163 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9164 int iVal, /* Column number */ 9165 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9166 ); 9167 9168 /* 9169 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9170 ** 9171 ** This function should only be used with iterator objects passed to a 9172 ** conflict-handler callback by [sqlite3changeset_apply()] with either 9173 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9174 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9175 ** is set to NULL. 9176 ** 9177 ** Argument iVal must be greater than or equal to 0, and less than the number 9178 ** of columns in the table affected by the current change. Otherwise, 9179 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9180 ** 9181 ** If successful, this function sets *ppValue to point to a protected 9182 ** sqlite3_value object containing the iVal'th value from the 9183 ** "conflicting row" associated with the current conflict-handler callback 9184 ** and returns SQLITE_OK. 9185 ** 9186 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9187 ** is returned and *ppValue is set to NULL. 9188 */ 9189 int sqlite3changeset_conflict( 9190 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9191 int iVal, /* Column number */ 9192 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9193 ); 9194 9195 /* 9196 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9197 ** 9198 ** This function may only be called with an iterator passed to an 9199 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9200 ** it sets the output variable to the total number of known foreign key 9201 ** violations in the destination database and returns SQLITE_OK. 9202 ** 9203 ** In all other cases this function returns SQLITE_MISUSE. 9204 */ 9205 int sqlite3changeset_fk_conflicts( 9206 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9207 int *pnOut /* OUT: Number of FK violations */ 9208 ); 9209 9210 9211 /* 9212 ** CAPI3REF: Finalize A Changeset Iterator 9213 ** 9214 ** This function is used to finalize an iterator allocated with 9215 ** [sqlite3changeset_start()]. 9216 ** 9217 ** This function should only be called on iterators created using the 9218 ** [sqlite3changeset_start()] function. If an application calls this 9219 ** function with an iterator passed to a conflict-handler by 9220 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9221 ** call has no effect. 9222 ** 9223 ** If an error was encountered within a call to an sqlite3changeset_xxx() 9224 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9225 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9226 ** to that error is returned by this function. Otherwise, SQLITE_OK is 9227 ** returned. This is to allow the following pattern (pseudo-code): 9228 ** 9229 ** sqlite3changeset_start(); 9230 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 9231 ** // Do something with change. 9232 ** } 9233 ** rc = sqlite3changeset_finalize(); 9234 ** if( rc!=SQLITE_OK ){ 9235 ** // An error has occurred 9236 ** } 9237 */ 9238 int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9239 9240 /* 9241 ** CAPI3REF: Invert A Changeset 9242 ** 9243 ** This function is used to "invert" a changeset object. Applying an inverted 9244 ** changeset to a database reverses the effects of applying the uninverted 9245 ** changeset. Specifically: 9246 ** 9247 ** <ul> 9248 ** <li> Each DELETE change is changed to an INSERT, and 9249 ** <li> Each INSERT change is changed to a DELETE, and 9250 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9251 ** </ul> 9252 ** 9253 ** This function does not change the order in which changes appear within 9254 ** the changeset. It merely reverses the sense of each individual change. 9255 ** 9256 ** If successful, a pointer to a buffer containing the inverted changeset 9257 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9258 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9259 ** zeroed and an SQLite error code returned. 9260 ** 9261 ** It is the responsibility of the caller to eventually call sqlite3_free() 9262 ** on the *ppOut pointer to free the buffer allocation following a successful 9263 ** call to this function. 9264 ** 9265 ** WARNING/TODO: This function currently assumes that the input is a valid 9266 ** changeset. If it is not, the results are undefined. 9267 */ 9268 int sqlite3changeset_invert( 9269 int nIn, const void *pIn, /* Input changeset */ 9270 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9271 ); 9272 9273 /* 9274 ** CAPI3REF: Concatenate Two Changeset Objects 9275 ** 9276 ** This function is used to concatenate two changesets, A and B, into a 9277 ** single changeset. The result is a changeset equivalent to applying 9278 ** changeset A followed by changeset B. 9279 ** 9280 ** This function combines the two input changesets using an 9281 ** sqlite3_changegroup object. Calling it produces similar results as the 9282 ** following code fragment: 9283 ** 9284 ** sqlite3_changegroup *pGrp; 9285 ** rc = sqlite3_changegroup_new(&pGrp); 9286 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9287 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9288 ** if( rc==SQLITE_OK ){ 9289 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9290 ** }else{ 9291 ** *ppOut = 0; 9292 ** *pnOut = 0; 9293 ** } 9294 ** 9295 ** Refer to the sqlite3_changegroup documentation below for details. 9296 */ 9297 int sqlite3changeset_concat( 9298 int nA, /* Number of bytes in buffer pA */ 9299 void *pA, /* Pointer to buffer containing changeset A */ 9300 int nB, /* Number of bytes in buffer pB */ 9301 void *pB, /* Pointer to buffer containing changeset B */ 9302 int *pnOut, /* OUT: Number of bytes in output changeset */ 9303 void **ppOut /* OUT: Buffer containing output changeset */ 9304 ); 9305 9306 9307 /* 9308 ** CAPI3REF: Changegroup Handle 9309 */ 9310 typedef struct sqlite3_changegroup sqlite3_changegroup; 9311 9312 /* 9313 ** CAPI3REF: Create A New Changegroup Object 9314 ** 9315 ** An sqlite3_changegroup object is used to combine two or more changesets 9316 ** (or patchsets) into a single changeset (or patchset). A single changegroup 9317 ** object may combine changesets or patchsets, but not both. The output is 9318 ** always in the same format as the input. 9319 ** 9320 ** If successful, this function returns SQLITE_OK and populates (*pp) with 9321 ** a pointer to a new sqlite3_changegroup object before returning. The caller 9322 ** should eventually free the returned object using a call to 9323 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9324 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9325 ** 9326 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 9327 ** 9328 ** <ul> 9329 ** <li> It is created using a call to sqlite3changegroup_new(). 9330 ** 9331 ** <li> Zero or more changesets (or patchsets) are added to the object 9332 ** by calling sqlite3changegroup_add(). 9333 ** 9334 ** <li> The result of combining all input changesets together is obtained 9335 ** by the application via a call to sqlite3changegroup_output(). 9336 ** 9337 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9338 ** </ul> 9339 ** 9340 ** Any number of calls to add() and output() may be made between the calls to 9341 ** new() and delete(), and in any order. 9342 ** 9343 ** As well as the regular sqlite3changegroup_add() and 9344 ** sqlite3changegroup_output() functions, also available are the streaming 9345 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9346 */ 9347 int sqlite3changegroup_new(sqlite3_changegroup **pp); 9348 9349 /* 9350 ** CAPI3REF: Add A Changeset To A Changegroup 9351 ** 9352 ** Add all changes within the changeset (or patchset) in buffer pData (size 9353 ** nData bytes) to the changegroup. 9354 ** 9355 ** If the buffer contains a patchset, then all prior calls to this function 9356 ** on the same changegroup object must also have specified patchsets. Or, if 9357 ** the buffer contains a changeset, so must have the earlier calls to this 9358 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9359 ** to the changegroup. 9360 ** 9361 ** Rows within the changeset and changegroup are identified by the values in 9362 ** their PRIMARY KEY columns. A change in the changeset is considered to 9363 ** apply to the same row as a change already present in the changegroup if 9364 ** the two rows have the same primary key. 9365 ** 9366 ** Changes to rows that do not already appear in the changegroup are 9367 ** simply copied into it. Or, if both the new changeset and the changegroup 9368 ** contain changes that apply to a single row, the final contents of the 9369 ** changegroup depends on the type of each change, as follows: 9370 ** 9371 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9372 ** <tr><th style="white-space:pre">Existing Change </th> 9373 ** <th style="white-space:pre">New Change </th> 9374 ** <th>Output Change 9375 ** <tr><td>INSERT <td>INSERT <td> 9376 ** The new change is ignored. This case does not occur if the new 9377 ** changeset was recorded immediately after the changesets already 9378 ** added to the changegroup. 9379 ** <tr><td>INSERT <td>UPDATE <td> 9380 ** The INSERT change remains in the changegroup. The values in the 9381 ** INSERT change are modified as if the row was inserted by the 9382 ** existing change and then updated according to the new change. 9383 ** <tr><td>INSERT <td>DELETE <td> 9384 ** The existing INSERT is removed from the changegroup. The DELETE is 9385 ** not added. 9386 ** <tr><td>UPDATE <td>INSERT <td> 9387 ** The new change is ignored. This case does not occur if the new 9388 ** changeset was recorded immediately after the changesets already 9389 ** added to the changegroup. 9390 ** <tr><td>UPDATE <td>UPDATE <td> 9391 ** The existing UPDATE remains within the changegroup. It is amended 9392 ** so that the accompanying values are as if the row was updated once 9393 ** by the existing change and then again by the new change. 9394 ** <tr><td>UPDATE <td>DELETE <td> 9395 ** The existing UPDATE is replaced by the new DELETE within the 9396 ** changegroup. 9397 ** <tr><td>DELETE <td>INSERT <td> 9398 ** If one or more of the column values in the row inserted by the 9399 ** new change differ from those in the row deleted by the existing 9400 ** change, the existing DELETE is replaced by an UPDATE within the 9401 ** changegroup. Otherwise, if the inserted row is exactly the same 9402 ** as the deleted row, the existing DELETE is simply discarded. 9403 ** <tr><td>DELETE <td>UPDATE <td> 9404 ** The new change is ignored. This case does not occur if the new 9405 ** changeset was recorded immediately after the changesets already 9406 ** added to the changegroup. 9407 ** <tr><td>DELETE <td>DELETE <td> 9408 ** The new change is ignored. This case does not occur if the new 9409 ** changeset was recorded immediately after the changesets already 9410 ** added to the changegroup. 9411 ** </table> 9412 ** 9413 ** If the new changeset contains changes to a table that is already present 9414 ** in the changegroup, then the number of columns and the position of the 9415 ** primary key columns for the table must be consistent. If this is not the 9416 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 9417 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9418 ** returned. Or, if an out-of-memory condition occurs during processing, this 9419 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9420 ** final contents of the changegroup is undefined. 9421 ** 9422 ** If no error occurs, SQLITE_OK is returned. 9423 */ 9424 int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9425 9426 /* 9427 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 9428 ** 9429 ** Obtain a buffer containing a changeset (or patchset) representing the 9430 ** current contents of the changegroup. If the inputs to the changegroup 9431 ** were themselves changesets, the output is a changeset. Or, if the 9432 ** inputs were patchsets, the output is also a patchset. 9433 ** 9434 ** As with the output of the sqlite3session_changeset() and 9435 ** sqlite3session_patchset() functions, all changes related to a single 9436 ** table are grouped together in the output of this function. Tables appear 9437 ** in the same order as for the very first changeset added to the changegroup. 9438 ** If the second or subsequent changesets added to the changegroup contain 9439 ** changes for tables that do not appear in the first changeset, they are 9440 ** appended onto the end of the output changeset, again in the order in 9441 ** which they are first encountered. 9442 ** 9443 ** If an error occurs, an SQLite error code is returned and the output 9444 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9445 ** is returned and the output variables are set to the size of and a 9446 ** pointer to the output buffer, respectively. In this case it is the 9447 ** responsibility of the caller to eventually free the buffer using a 9448 ** call to sqlite3_free(). 9449 */ 9450 int sqlite3changegroup_output( 9451 sqlite3_changegroup*, 9452 int *pnData, /* OUT: Size of output buffer in bytes */ 9453 void **ppData /* OUT: Pointer to output buffer */ 9454 ); 9455 9456 /* 9457 ** CAPI3REF: Delete A Changegroup Object 9458 */ 9459 void sqlite3changegroup_delete(sqlite3_changegroup*); 9460 9461 /* 9462 ** CAPI3REF: Apply A Changeset To A Database 9463 ** 9464 ** Apply a changeset to a database. This function attempts to update the 9465 ** "main" database attached to handle db with the changes found in the 9466 ** changeset passed via the second and third arguments. 9467 ** 9468 ** The fourth argument (xFilter) passed to this function is the "filter 9469 ** callback". If it is not NULL, then for each table affected by at least one 9470 ** change in the changeset, the filter callback is invoked with 9471 ** the table name as the second argument, and a copy of the context pointer 9472 ** passed as the sixth argument to this function as the first. If the "filter 9473 ** callback" returns zero, then no attempt is made to apply any changes to 9474 ** the table. Otherwise, if the return value is non-zero or the xFilter 9475 ** argument to this function is NULL, all changes related to the table are 9476 ** attempted. 9477 ** 9478 ** For each table that is not excluded by the filter callback, this function 9479 ** tests that the target database contains a compatible table. A table is 9480 ** considered compatible if all of the following are true: 9481 ** 9482 ** <ul> 9483 ** <li> The table has the same name as the name recorded in the 9484 ** changeset, and 9485 ** <li> The table has the same number of columns as recorded in the 9486 ** changeset, and 9487 ** <li> The table has primary key columns in the same position as 9488 ** recorded in the changeset. 9489 ** </ul> 9490 ** 9491 ** If there is no compatible table, it is not an error, but none of the 9492 ** changes associated with the table are applied. A warning message is issued 9493 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9494 ** one such warning is issued for each table in the changeset. 9495 ** 9496 ** For each change for which there is a compatible table, an attempt is made 9497 ** to modify the table contents according to the UPDATE, INSERT or DELETE 9498 ** change. If a change cannot be applied cleanly, the conflict handler 9499 ** function passed as the fifth argument to sqlite3changeset_apply() may be 9500 ** invoked. A description of exactly when the conflict handler is invoked for 9501 ** each type of change is below. 9502 ** 9503 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9504 ** of passing anything other than a valid function pointer as the xConflict 9505 ** argument are undefined. 9506 ** 9507 ** Each time the conflict handler function is invoked, it must return one 9508 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9509 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9510 ** if the second argument passed to the conflict handler is either 9511 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9512 ** returns an illegal value, any changes already made are rolled back and 9513 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9514 ** actions are taken by sqlite3changeset_apply() depending on the value 9515 ** returned by each invocation of the conflict-handler function. Refer to 9516 ** the documentation for the three 9517 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 9518 ** 9519 ** <dl> 9520 ** <dt>DELETE Changes<dd> 9521 ** For each DELETE change, this function checks if the target database 9522 ** contains a row with the same primary key value (or values) as the 9523 ** original row values stored in the changeset. If it does, and the values 9524 ** stored in all non-primary key columns also match the values stored in 9525 ** the changeset the row is deleted from the target database. 9526 ** 9527 ** If a row with matching primary key values is found, but one or more of 9528 ** the non-primary key fields contains a value different from the original 9529 ** row value stored in the changeset, the conflict-handler function is 9530 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. 9531 ** 9532 ** If no row with matching primary key values is found in the database, 9533 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9534 ** passed as the second argument. 9535 ** 9536 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9537 ** (which can only happen if a foreign key constraint is violated), the 9538 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9539 ** passed as the second argument. This includes the case where the DELETE 9540 ** operation is attempted because an earlier call to the conflict handler 9541 ** function returned [SQLITE_CHANGESET_REPLACE]. 9542 ** 9543 ** <dt>INSERT Changes<dd> 9544 ** For each INSERT change, an attempt is made to insert the new row into 9545 ** the database. 9546 ** 9547 ** If the attempt to insert the row fails because the database already 9548 ** contains a row with the same primary key values, the conflict handler 9549 ** function is invoked with the second argument set to 9550 ** [SQLITE_CHANGESET_CONFLICT]. 9551 ** 9552 ** If the attempt to insert the row fails because of some other constraint 9553 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9554 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9555 ** This includes the case where the INSERT operation is re-attempted because 9556 ** an earlier call to the conflict handler function returned 9557 ** [SQLITE_CHANGESET_REPLACE]. 9558 ** 9559 ** <dt>UPDATE Changes<dd> 9560 ** For each UPDATE change, this function checks if the target database 9561 ** contains a row with the same primary key value (or values) as the 9562 ** original row values stored in the changeset. If it does, and the values 9563 ** stored in all non-primary key columns also match the values stored in 9564 ** the changeset the row is updated within the target database. 9565 ** 9566 ** If a row with matching primary key values is found, but one or more of 9567 ** the non-primary key fields contains a value different from an original 9568 ** row value stored in the changeset, the conflict-handler function is 9569 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9570 ** UPDATE changes only contain values for non-primary key fields that are 9571 ** to be modified, only those fields need to match the original values to 9572 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9573 ** 9574 ** If no row with matching primary key values is found in the database, 9575 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9576 ** passed as the second argument. 9577 ** 9578 ** If the UPDATE operation is attempted, but SQLite returns 9579 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9580 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9581 ** This includes the case where the UPDATE operation is attempted after 9582 ** an earlier call to the conflict handler function returned 9583 ** [SQLITE_CHANGESET_REPLACE]. 9584 ** </dl> 9585 ** 9586 ** It is safe to execute SQL statements, including those that write to the 9587 ** table that the callback related to, from within the xConflict callback. 9588 ** This can be used to further customize the applications conflict 9589 ** resolution strategy. 9590 ** 9591 ** All changes made by this function are enclosed in a savepoint transaction. 9592 ** If any other error (aside from a constraint failure when attempting to 9593 ** write to the target database) occurs, then the savepoint transaction is 9594 ** rolled back, restoring the target database to its original state, and an 9595 ** SQLite error code returned. 9596 */ 9597 int sqlite3changeset_apply( 9598 sqlite3 *db, /* Apply change to "main" db of this handle */ 9599 int nChangeset, /* Size of changeset in bytes */ 9600 void *pChangeset, /* Changeset blob */ 9601 int(*xFilter)( 9602 void *pCtx, /* Copy of sixth arg to _apply() */ 9603 const char *zTab /* Table name */ 9604 ), 9605 int(*xConflict)( 9606 void *pCtx, /* Copy of sixth arg to _apply() */ 9607 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9608 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9609 ), 9610 void *pCtx /* First argument passed to xConflict */ 9611 ); 9612 9613 /* 9614 ** CAPI3REF: Constants Passed To The Conflict Handler 9615 ** 9616 ** Values that may be passed as the second argument to a conflict-handler. 9617 ** 9618 ** <dl> 9619 ** <dt>SQLITE_CHANGESET_DATA<dd> 9620 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 9621 ** when processing a DELETE or UPDATE change if a row with the required 9622 ** PRIMARY KEY fields is present in the database, but one or more other 9623 ** (non primary-key) fields modified by the update do not contain the 9624 ** expected "before" values. 9625 ** 9626 ** The conflicting row, in this case, is the database row with the matching 9627 ** primary key. 9628 ** 9629 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9630 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9631 ** argument when processing a DELETE or UPDATE change if a row with the 9632 ** required PRIMARY KEY fields is not present in the database. 9633 ** 9634 ** There is no conflicting row in this case. The results of invoking the 9635 ** sqlite3changeset_conflict() API are undefined. 9636 ** 9637 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9638 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 9639 ** handler while processing an INSERT change if the operation would result 9640 ** in duplicate primary key values. 9641 ** 9642 ** The conflicting row in this case is the database row with the matching 9643 ** primary key. 9644 ** 9645 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9646 ** If foreign key handling is enabled, and applying a changeset leaves the 9647 ** database in a state containing foreign key violations, the conflict 9648 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9649 ** exactly once before the changeset is committed. If the conflict handler 9650 ** returns CHANGESET_OMIT, the changes, including those that caused the 9651 ** foreign key constraint violation, are committed. Or, if it returns 9652 ** CHANGESET_ABORT, the changeset is rolled back. 9653 ** 9654 ** No current or conflicting row information is provided. The only function 9655 ** it is possible to call on the supplied sqlite3_changeset_iter handle 9656 ** is sqlite3changeset_fk_conflicts(). 9657 ** 9658 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9659 ** If any other constraint violation occurs while applying a change (i.e. 9660 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9661 ** invoked with CHANGESET_CONSTRAINT as the second argument. 9662 ** 9663 ** There is no conflicting row in this case. The results of invoking the 9664 ** sqlite3changeset_conflict() API are undefined. 9665 ** 9666 ** </dl> 9667 */ 9668 #define SQLITE_CHANGESET_DATA 1 9669 #define SQLITE_CHANGESET_NOTFOUND 2 9670 #define SQLITE_CHANGESET_CONFLICT 3 9671 #define SQLITE_CHANGESET_CONSTRAINT 4 9672 #define SQLITE_CHANGESET_FOREIGN_KEY 5 9673 9674 /* 9675 ** CAPI3REF: Constants Returned By The Conflict Handler 9676 ** 9677 ** A conflict handler callback must return one of the following three values. 9678 ** 9679 ** <dl> 9680 ** <dt>SQLITE_CHANGESET_OMIT<dd> 9681 ** If a conflict handler returns this value no special action is taken. The 9682 ** change that caused the conflict is not applied. The session module 9683 ** continues to the next change in the changeset. 9684 ** 9685 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 9686 ** This value may only be returned if the second argument to the conflict 9687 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9688 ** is not the case, any changes applied so far are rolled back and the 9689 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9690 ** 9691 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9692 ** handler, then the conflicting row is either updated or deleted, depending 9693 ** on the type of change. 9694 ** 9695 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9696 ** handler, then the conflicting row is removed from the database and a 9697 ** second attempt to apply the change is made. If this second attempt fails, 9698 ** the original row is restored to the database before continuing. 9699 ** 9700 ** <dt>SQLITE_CHANGESET_ABORT<dd> 9701 ** If this value is returned, any changes applied so far are rolled back 9702 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9703 ** </dl> 9704 */ 9705 #define SQLITE_CHANGESET_OMIT 0 9706 #define SQLITE_CHANGESET_REPLACE 1 9707 #define SQLITE_CHANGESET_ABORT 2 9708 9709 /* 9710 ** CAPI3REF: Streaming Versions of API functions. 9711 ** 9712 ** The six streaming API xxx_strm() functions serve similar purposes to the 9713 ** corresponding non-streaming API functions: 9714 ** 9715 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9716 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9717 ** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9718 ** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9719 ** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9720 ** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9721 ** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9722 ** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9723 ** </table> 9724 ** 9725 ** Non-streaming functions that accept changesets (or patchsets) as input 9726 ** require that the entire changeset be stored in a single buffer in memory. 9727 ** Similarly, those that return a changeset or patchset do so by returning 9728 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 9729 ** Normally this is convenient. However, if an application running in a 9730 ** low-memory environment is required to handle very large changesets, the 9731 ** large contiguous memory allocations required can become onerous. 9732 ** 9733 ** In order to avoid this problem, instead of a single large buffer, input 9734 ** is passed to a streaming API functions by way of a callback function that 9735 ** the sessions module invokes to incrementally request input data as it is 9736 ** required. In all cases, a pair of API function parameters such as 9737 ** 9738 ** <pre> 9739 ** int nChangeset, 9740 ** void *pChangeset, 9741 ** </pre> 9742 ** 9743 ** Is replaced by: 9744 ** 9745 ** <pre> 9746 ** int (*xInput)(void *pIn, void *pData, int *pnData), 9747 ** void *pIn, 9748 ** </pre> 9749 ** 9750 ** Each time the xInput callback is invoked by the sessions module, the first 9751 ** argument passed is a copy of the supplied pIn context pointer. The second 9752 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9753 ** error occurs the xInput method should copy up to (*pnData) bytes of data 9754 ** into the buffer and set (*pnData) to the actual number of bytes copied 9755 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9756 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9757 ** error code should be returned. In all cases, if an xInput callback returns 9758 ** an error, all processing is abandoned and the streaming API function 9759 ** returns a copy of the error code to the caller. 9760 ** 9761 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9762 ** invoked by the sessions module at any point during the lifetime of the 9763 ** iterator. If such an xInput callback returns an error, the iterator enters 9764 ** an error state, whereby all subsequent calls to iterator functions 9765 ** immediately fail with the same error code as returned by xInput. 9766 ** 9767 ** Similarly, streaming API functions that return changesets (or patchsets) 9768 ** return them in chunks by way of a callback function instead of via a 9769 ** pointer to a single large buffer. In this case, a pair of parameters such 9770 ** as: 9771 ** 9772 ** <pre> 9773 ** int *pnChangeset, 9774 ** void **ppChangeset, 9775 ** </pre> 9776 ** 9777 ** Is replaced by: 9778 ** 9779 ** <pre> 9780 ** int (*xOutput)(void *pOut, const void *pData, int nData), 9781 ** void *pOut 9782 ** </pre> 9783 ** 9784 ** The xOutput callback is invoked zero or more times to return data to 9785 ** the application. The first parameter passed to each call is a copy of the 9786 ** pOut pointer supplied by the application. The second parameter, pData, 9787 ** points to a buffer nData bytes in size containing the chunk of output 9788 ** data being returned. If the xOutput callback successfully processes the 9789 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9790 ** it should return some other SQLite error code. In this case processing 9791 ** is immediately abandoned and the streaming API function returns a copy 9792 ** of the xOutput error code to the application. 9793 ** 9794 ** The sessions module never invokes an xOutput callback with the third 9795 ** parameter set to a value less than or equal to zero. Other than this, 9796 ** no guarantees are made as to the size of the chunks of data returned. 9797 */ 9798 int sqlite3changeset_apply_strm( 9799 sqlite3 *db, /* Apply change to "main" db of this handle */ 9800 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9801 void *pIn, /* First arg for xInput */ 9802 int(*xFilter)( 9803 void *pCtx, /* Copy of sixth arg to _apply() */ 9804 const char *zTab /* Table name */ 9805 ), 9806 int(*xConflict)( 9807 void *pCtx, /* Copy of sixth arg to _apply() */ 9808 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9809 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9810 ), 9811 void *pCtx /* First argument passed to xConflict */ 9812 ); 9813 int sqlite3changeset_concat_strm( 9814 int (*xInputA)(void *pIn, void *pData, int *pnData), 9815 void *pInA, 9816 int (*xInputB)(void *pIn, void *pData, int *pnData), 9817 void *pInB, 9818 int (*xOutput)(void *pOut, const void *pData, int nData), 9819 void *pOut 9820 ); 9821 int sqlite3changeset_invert_strm( 9822 int (*xInput)(void *pIn, void *pData, int *pnData), 9823 void *pIn, 9824 int (*xOutput)(void *pOut, const void *pData, int nData), 9825 void *pOut 9826 ); 9827 int sqlite3changeset_start_strm( 9828 sqlite3_changeset_iter **pp, 9829 int (*xInput)(void *pIn, void *pData, int *pnData), 9830 void *pIn 9831 ); 9832 int sqlite3session_changeset_strm( 9833 sqlite3_session *pSession, 9834 int (*xOutput)(void *pOut, const void *pData, int nData), 9835 void *pOut 9836 ); 9837 int sqlite3session_patchset_strm( 9838 sqlite3_session *pSession, 9839 int (*xOutput)(void *pOut, const void *pData, int nData), 9840 void *pOut 9841 ); 9842 int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9843 int (*xInput)(void *pIn, void *pData, int *pnData), 9844 void *pIn 9845 ); 9846 int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9847 int (*xOutput)(void *pOut, const void *pData, int nData), 9848 void *pOut 9849 ); 9850 9851 9852 /* 9853 ** Make sure we can call this stuff from C++. 9854 */ 9855 #ifdef __cplusplus 9856 } 9857 #endif 9858 9859 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9860 9861 /******** End of sqlite3session.h *********/ 9862 /******** Begin file fts5.h *********/ 9863 /* 9864 ** 2014 May 31 9865 ** 9866 ** The author disclaims copyright to this source code. In place of 9867 ** a legal notice, here is a blessing: 9868 ** 9869 ** May you do good and not evil. 9870 ** May you find forgiveness for yourself and forgive others. 9871 ** May you share freely, never taking more than you give. 9872 ** 9873 ****************************************************************************** 9874 ** 9875 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 9876 ** FTS5 may be extended with: 9877 ** 9878 ** * custom tokenizers, and 9879 ** * custom auxiliary functions. 9880 */ 9881 9882 9883 #ifndef _FTS5_H 9884 #define _FTS5_H 9885 9886 9887 #ifdef __cplusplus 9888 extern "C" { 9889 #endif 9890 9891 /************************************************************************* 9892 ** CUSTOM AUXILIARY FUNCTIONS 9893 ** 9894 ** Virtual table implementations may overload SQL functions by implementing 9895 ** the sqlite3_module.xFindFunction() method. 9896 */ 9897 9898 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 9899 typedef struct Fts5Context Fts5Context; 9900 typedef struct Fts5PhraseIter Fts5PhraseIter; 9901 9902 typedef void (*fts5_extension_function)( 9903 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 9904 Fts5Context *pFts, /* First arg to pass to pApi functions */ 9905 sqlite3_context *pCtx, /* Context for returning result/error */ 9906 int nVal, /* Number of values in apVal[] array */ 9907 sqlite3_value **apVal /* Array of trailing arguments */ 9908 ); 9909 9910 struct Fts5PhraseIter { 9911 const unsigned char *a; 9912 const unsigned char *b; 9913 }; 9914 9915 /* 9916 ** EXTENSION API FUNCTIONS 9917 ** 9918 ** xUserData(pFts): 9919 ** Return a copy of the context pointer the extension function was 9920 ** registered with. 9921 ** 9922 ** xColumnTotalSize(pFts, iCol, pnToken): 9923 ** If parameter iCol is less than zero, set output variable *pnToken 9924 ** to the total number of tokens in the FTS5 table. Or, if iCol is 9925 ** non-negative but less than the number of columns in the table, return 9926 ** the total number of tokens in column iCol, considering all rows in 9927 ** the FTS5 table. 9928 ** 9929 ** If parameter iCol is greater than or equal to the number of columns 9930 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9931 ** an OOM condition or IO error), an appropriate SQLite error code is 9932 ** returned. 9933 ** 9934 ** xColumnCount(pFts): 9935 ** Return the number of columns in the table. 9936 ** 9937 ** xColumnSize(pFts, iCol, pnToken): 9938 ** If parameter iCol is less than zero, set output variable *pnToken 9939 ** to the total number of tokens in the current row. Or, if iCol is 9940 ** non-negative but less than the number of columns in the table, set 9941 ** *pnToken to the number of tokens in column iCol of the current row. 9942 ** 9943 ** If parameter iCol is greater than or equal to the number of columns 9944 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9945 ** an OOM condition or IO error), an appropriate SQLite error code is 9946 ** returned. 9947 ** 9948 ** This function may be quite inefficient if used with an FTS5 table 9949 ** created with the "columnsize=0" option. 9950 ** 9951 ** xColumnText: 9952 ** This function attempts to retrieve the text of column iCol of the 9953 ** current document. If successful, (*pz) is set to point to a buffer 9954 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 9955 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 9956 ** if an error occurs, an SQLite error code is returned and the final values 9957 ** of (*pz) and (*pn) are undefined. 9958 ** 9959 ** xPhraseCount: 9960 ** Returns the number of phrases in the current query expression. 9961 ** 9962 ** xPhraseSize: 9963 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 9964 ** are numbered starting from zero. 9965 ** 9966 ** xInstCount: 9967 ** Set *pnInst to the total number of occurrences of all phrases within 9968 ** the query within the current row. Return SQLITE_OK if successful, or 9969 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 9970 ** 9971 ** This API can be quite slow if used with an FTS5 table created with the 9972 ** "detail=none" or "detail=column" option. If the FTS5 table is created 9973 ** with either "detail=none" or "detail=column" and "content=" option 9974 ** (i.e. if it is a contentless table), then this API always returns 0. 9975 ** 9976 ** xInst: 9977 ** Query for the details of phrase match iIdx within the current row. 9978 ** Phrase matches are numbered starting from zero, so the iIdx argument 9979 ** should be greater than or equal to zero and smaller than the value 9980 ** output by xInstCount(). 9981 ** 9982 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 9983 ** to the column in which it occurs and *piOff the token offset of the 9984 ** first token of the phrase. The exception is if the table was created 9985 ** with the offsets=0 option specified. In this case *piOff is always 9986 ** set to -1. 9987 ** 9988 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 9989 ** if an error occurs. 9990 ** 9991 ** This API can be quite slow if used with an FTS5 table created with the 9992 ** "detail=none" or "detail=column" option. 9993 ** 9994 ** xRowid: 9995 ** Returns the rowid of the current row. 9996 ** 9997 ** xTokenize: 9998 ** Tokenize text using the tokenizer belonging to the FTS5 table. 9999 ** 10000 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 10001 ** This API function is used to query the FTS table for phrase iPhrase 10002 ** of the current query. Specifically, a query equivalent to: 10003 ** 10004 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 10005 ** 10006 ** with $p set to a phrase equivalent to the phrase iPhrase of the 10007 ** current query is executed. Any column filter that applies to 10008 ** phrase iPhrase of the current query is included in $p. For each 10009 ** row visited, the callback function passed as the fourth argument 10010 ** is invoked. The context and API objects passed to the callback 10011 ** function may be used to access the properties of each matched row. 10012 ** Invoking Api.xUserData() returns a copy of the pointer passed as 10013 ** the third argument to pUserData. 10014 ** 10015 ** If the callback function returns any value other than SQLITE_OK, the 10016 ** query is abandoned and the xQueryPhrase function returns immediately. 10017 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 10018 ** Otherwise, the error code is propagated upwards. 10019 ** 10020 ** If the query runs to completion without incident, SQLITE_OK is returned. 10021 ** Or, if some error occurs before the query completes or is aborted by 10022 ** the callback, an SQLite error code is returned. 10023 ** 10024 ** 10025 ** xSetAuxdata(pFts5, pAux, xDelete) 10026 ** 10027 ** Save the pointer passed as the second argument as the extension functions 10028 ** "auxiliary data". The pointer may then be retrieved by the current or any 10029 ** future invocation of the same fts5 extension function made as part of 10030 ** of the same MATCH query using the xGetAuxdata() API. 10031 ** 10032 ** Each extension function is allocated a single auxiliary data slot for 10033 ** each FTS query (MATCH expression). If the extension function is invoked 10034 ** more than once for a single FTS query, then all invocations share a 10035 ** single auxiliary data context. 10036 ** 10037 ** If there is already an auxiliary data pointer when this function is 10038 ** invoked, then it is replaced by the new pointer. If an xDelete callback 10039 ** was specified along with the original pointer, it is invoked at this 10040 ** point. 10041 ** 10042 ** The xDelete callback, if one is specified, is also invoked on the 10043 ** auxiliary data pointer after the FTS5 query has finished. 10044 ** 10045 ** If an error (e.g. an OOM condition) occurs within this function, an 10046 ** the auxiliary data is set to NULL and an error code returned. If the 10047 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 10048 ** pointer before returning. 10049 ** 10050 ** 10051 ** xGetAuxdata(pFts5, bClear) 10052 ** 10053 ** Returns the current auxiliary data pointer for the fts5 extension 10054 ** function. See the xSetAuxdata() method for details. 10055 ** 10056 ** If the bClear argument is non-zero, then the auxiliary data is cleared 10057 ** (set to NULL) before this function returns. In this case the xDelete, 10058 ** if any, is not invoked. 10059 ** 10060 ** 10061 ** xRowCount(pFts5, pnRow) 10062 ** 10063 ** This function is used to retrieve the total number of rows in the table. 10064 ** In other words, the same value that would be returned by: 10065 ** 10066 ** SELECT count(*) FROM ftstable; 10067 ** 10068 ** xPhraseFirst() 10069 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 10070 ** method, to iterate through all instances of a single query phrase within 10071 ** the current row. This is the same information as is accessible via the 10072 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 10073 ** to use, this API may be faster under some circumstances. To iterate 10074 ** through instances of phrase iPhrase, use the following code: 10075 ** 10076 ** Fts5PhraseIter iter; 10077 ** int iCol, iOff; 10078 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 10079 ** iCol>=0; 10080 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 10081 ** ){ 10082 ** // An instance of phrase iPhrase at offset iOff of column iCol 10083 ** } 10084 ** 10085 ** The Fts5PhraseIter structure is defined above. Applications should not 10086 ** modify this structure directly - it should only be used as shown above 10087 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 10088 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 10089 ** 10090 ** This API can be quite slow if used with an FTS5 table created with the 10091 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10092 ** with either "detail=none" or "detail=column" and "content=" option 10093 ** (i.e. if it is a contentless table), then this API always iterates 10094 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 10095 ** 10096 ** xPhraseNext() 10097 ** See xPhraseFirst above. 10098 ** 10099 ** xPhraseFirstColumn() 10100 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10101 ** and xPhraseNext() APIs described above. The difference is that instead 10102 ** of iterating through all instances of a phrase in the current row, these 10103 ** APIs are used to iterate through the set of columns in the current row 10104 ** that contain one or more instances of a specified phrase. For example: 10105 ** 10106 ** Fts5PhraseIter iter; 10107 ** int iCol; 10108 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10109 ** iCol>=0; 10110 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10111 ** ){ 10112 ** // Column iCol contains at least one instance of phrase iPhrase 10113 ** } 10114 ** 10115 ** This API can be quite slow if used with an FTS5 table created with the 10116 ** "detail=none" option. If the FTS5 table is created with either 10117 ** "detail=none" "content=" option (i.e. if it is a contentless table), 10118 ** then this API always iterates through an empty set (all calls to 10119 ** xPhraseFirstColumn() set iCol to -1). 10120 ** 10121 ** The information accessed using this API and its companion 10122 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10123 ** (or xInst/xInstCount). The chief advantage of this API is that it is 10124 ** significantly more efficient than those alternatives when used with 10125 ** "detail=column" tables. 10126 ** 10127 ** xPhraseNextColumn() 10128 ** See xPhraseFirstColumn above. 10129 */ 10130 struct Fts5ExtensionApi { 10131 int iVersion; /* Currently always set to 3 */ 10132 10133 void *(*xUserData)(Fts5Context*); 10134 10135 int (*xColumnCount)(Fts5Context*); 10136 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10137 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10138 10139 int (*xTokenize)(Fts5Context*, 10140 const char *pText, int nText, /* Text to tokenize */ 10141 void *pCtx, /* Context passed to xToken() */ 10142 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10143 ); 10144 10145 int (*xPhraseCount)(Fts5Context*); 10146 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10147 10148 int (*xInstCount)(Fts5Context*, int *pnInst); 10149 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10150 10151 sqlite3_int64 (*xRowid)(Fts5Context*); 10152 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10153 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10154 10155 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10156 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10157 ); 10158 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10159 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10160 10161 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10162 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10163 10164 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10165 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10166 }; 10167 10168 /* 10169 ** CUSTOM AUXILIARY FUNCTIONS 10170 *************************************************************************/ 10171 10172 /************************************************************************* 10173 ** CUSTOM TOKENIZERS 10174 ** 10175 ** Applications may also register custom tokenizer types. A tokenizer 10176 ** is registered by providing fts5 with a populated instance of the 10177 ** following structure. All structure methods must be defined, setting 10178 ** any member of the fts5_tokenizer struct to NULL leads to undefined 10179 ** behaviour. The structure methods are expected to function as follows: 10180 ** 10181 ** xCreate: 10182 ** This function is used to allocate and initialize a tokenizer instance. 10183 ** A tokenizer instance is required to actually tokenize text. 10184 ** 10185 ** The first argument passed to this function is a copy of the (void*) 10186 ** pointer provided by the application when the fts5_tokenizer object 10187 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 10188 ** The second and third arguments are an array of nul-terminated strings 10189 ** containing the tokenizer arguments, if any, specified following the 10190 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10191 ** to create the FTS5 table. 10192 ** 10193 ** The final argument is an output variable. If successful, (*ppOut) 10194 ** should be set to point to the new tokenizer handle and SQLITE_OK 10195 ** returned. If an error occurs, some value other than SQLITE_OK should 10196 ** be returned. In this case, fts5 assumes that the final value of *ppOut 10197 ** is undefined. 10198 ** 10199 ** xDelete: 10200 ** This function is invoked to delete a tokenizer handle previously 10201 ** allocated using xCreate(). Fts5 guarantees that this function will 10202 ** be invoked exactly once for each successful call to xCreate(). 10203 ** 10204 ** xTokenize: 10205 ** This function is expected to tokenize the nText byte string indicated 10206 ** by argument pText. pText may or may not be nul-terminated. The first 10207 ** argument passed to this function is a pointer to an Fts5Tokenizer object 10208 ** returned by an earlier call to xCreate(). 10209 ** 10210 ** The second argument indicates the reason that FTS5 is requesting 10211 ** tokenization of the supplied text. This is always one of the following 10212 ** four values: 10213 ** 10214 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10215 ** or removed from the FTS table. The tokenizer is being invoked to 10216 ** determine the set of tokens to add to (or delete from) the 10217 ** FTS index. 10218 ** 10219 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10220 ** against the FTS index. The tokenizer is being called to tokenize 10221 ** a bareword or quoted string specified as part of the query. 10222 ** 10223 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10224 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10225 ** followed by a "*" character, indicating that the last token 10226 ** returned by the tokenizer will be treated as a token prefix. 10227 ** 10228 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10229 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 10230 ** function. Or an fts5_api.xColumnSize() request made by the same 10231 ** on a columnsize=0 database. 10232 ** </ul> 10233 ** 10234 ** For each token in the input string, the supplied callback xToken() must 10235 ** be invoked. The first argument to it should be a copy of the pointer 10236 ** passed as the second argument to xTokenize(). The third and fourth 10237 ** arguments are a pointer to a buffer containing the token text, and the 10238 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10239 ** of the first byte of and first byte immediately following the text from 10240 ** which the token is derived within the input. 10241 ** 10242 ** The second argument passed to the xToken() callback ("tflags") should 10243 ** normally be set to 0. The exception is if the tokenizer supports 10244 ** synonyms. In this case see the discussion below for details. 10245 ** 10246 ** FTS5 assumes the xToken() callback is invoked for each token in the 10247 ** order that they occur within the input text. 10248 ** 10249 ** If an xToken() callback returns any value other than SQLITE_OK, then 10250 ** the tokenization should be abandoned and the xTokenize() method should 10251 ** immediately return a copy of the xToken() return value. Or, if the 10252 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10253 ** if an error occurs with the xTokenize() implementation itself, it 10254 ** may abandon the tokenization and return any error code other than 10255 ** SQLITE_OK or SQLITE_DONE. 10256 ** 10257 ** SYNONYM SUPPORT 10258 ** 10259 ** Custom tokenizers may also support synonyms. Consider a case in which a 10260 ** user wishes to query for a phrase such as "first place". Using the 10261 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 10262 ** of "first place" within the document set, but not alternative forms 10263 ** such as "1st place". In some applications, it would be better to match 10264 ** all instances of "first place" or "1st place" regardless of which form 10265 ** the user specified in the MATCH query text. 10266 ** 10267 ** There are several ways to approach this in FTS5: 10268 ** 10269 ** <ol><li> By mapping all synonyms to a single token. In this case, the 10270 ** In the above example, this means that the tokenizer returns the 10271 ** same token for inputs "first" and "1st". Say that token is in 10272 ** fact "first", so that when the user inserts the document "I won 10273 ** 1st place" entries are added to the index for tokens "i", "won", 10274 ** "first" and "place". If the user then queries for '1st + place', 10275 ** the tokenizer substitutes "first" for "1st" and the query works 10276 ** as expected. 10277 ** 10278 ** <li> By adding multiple synonyms for a single term to the FTS index. 10279 ** In this case, when tokenizing query text, the tokenizer may 10280 ** provide multiple synonyms for a single term within the document. 10281 ** FTS5 then queries the index for each synonym individually. For 10282 ** example, faced with the query: 10283 ** 10284 ** <codeblock> 10285 ** ... MATCH 'first place'</codeblock> 10286 ** 10287 ** the tokenizer offers both "1st" and "first" as synonyms for the 10288 ** first token in the MATCH query and FTS5 effectively runs a query 10289 ** similar to: 10290 ** 10291 ** <codeblock> 10292 ** ... MATCH '(first OR 1st) place'</codeblock> 10293 ** 10294 ** except that, for the purposes of auxiliary functions, the query 10295 ** still appears to contain just two phrases - "(first OR 1st)" 10296 ** being treated as a single phrase. 10297 ** 10298 ** <li> By adding multiple synonyms for a single term to the FTS index. 10299 ** Using this method, when tokenizing document text, the tokenizer 10300 ** provides multiple synonyms for each token. So that when a 10301 ** document such as "I won first place" is tokenized, entries are 10302 ** added to the FTS index for "i", "won", "first", "1st" and 10303 ** "place". 10304 ** 10305 ** This way, even if the tokenizer does not provide synonyms 10306 ** when tokenizing query text (it should not - to do would be 10307 ** inefficient), it doesn't matter if the user queries for 10308 ** 'first + place' or '1st + place', as there are entires in the 10309 ** FTS index corresponding to both forms of the first token. 10310 ** </ol> 10311 ** 10312 ** Whether it is parsing document or query text, any call to xToken that 10313 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10314 ** is considered to supply a synonym for the previous token. For example, 10315 ** when parsing the document "I won first place", a tokenizer that supports 10316 ** synonyms would call xToken() 5 times, as follows: 10317 ** 10318 ** <codeblock> 10319 ** xToken(pCtx, 0, "i", 1, 0, 1); 10320 ** xToken(pCtx, 0, "won", 3, 2, 5); 10321 ** xToken(pCtx, 0, "first", 5, 6, 11); 10322 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10323 ** xToken(pCtx, 0, "place", 5, 12, 17); 10324 **</codeblock> 10325 ** 10326 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10327 ** xToken() is called. Multiple synonyms may be specified for a single token 10328 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10329 ** There is no limit to the number of synonyms that may be provided for a 10330 ** single token. 10331 ** 10332 ** In many cases, method (1) above is the best approach. It does not add 10333 ** extra data to the FTS index or require FTS5 to query for multiple terms, 10334 ** so it is efficient in terms of disk space and query speed. However, it 10335 ** does not support prefix queries very well. If, as suggested above, the 10336 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 10337 ** 10338 ** <codeblock> 10339 ** ... MATCH '1s*'</codeblock> 10340 ** 10341 ** will not match documents that contain the token "1st" (as the tokenizer 10342 ** will probably not map "1s" to any prefix of "first"). 10343 ** 10344 ** For full prefix support, method (3) may be preferred. In this case, 10345 ** because the index contains entries for both "first" and "1st", prefix 10346 ** queries such as 'fi*' or '1s*' will match correctly. However, because 10347 ** extra entries are added to the FTS index, this method uses more space 10348 ** within the database. 10349 ** 10350 ** Method (2) offers a midpoint between (1) and (3). Using this method, 10351 ** a query such as '1s*' will match documents that contain the literal 10352 ** token "1st", but not "first" (assuming the tokenizer is not able to 10353 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 10354 ** will match against "1st" and "first". This method does not require 10355 ** extra disk space, as no extra entries are added to the FTS index. 10356 ** On the other hand, it may require more CPU cycles to run MATCH queries, 10357 ** as separate queries of the FTS index are required for each synonym. 10358 ** 10359 ** When using methods (2) or (3), it is important that the tokenizer only 10360 ** provide synonyms when tokenizing document text (method (2)) or query 10361 ** text (method (3)), not both. Doing so will not cause any errors, but is 10362 ** inefficient. 10363 */ 10364 typedef struct Fts5Tokenizer Fts5Tokenizer; 10365 typedef struct fts5_tokenizer fts5_tokenizer; 10366 struct fts5_tokenizer { 10367 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10368 void (*xDelete)(Fts5Tokenizer*); 10369 int (*xTokenize)(Fts5Tokenizer*, 10370 void *pCtx, 10371 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10372 const char *pText, int nText, 10373 int (*xToken)( 10374 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10375 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10376 const char *pToken, /* Pointer to buffer containing token */ 10377 int nToken, /* Size of token in bytes */ 10378 int iStart, /* Byte offset of token within input text */ 10379 int iEnd /* Byte offset of end of token within input text */ 10380 ) 10381 ); 10382 }; 10383 10384 /* Flags that may be passed as the third argument to xTokenize() */ 10385 #define FTS5_TOKENIZE_QUERY 0x0001 10386 #define FTS5_TOKENIZE_PREFIX 0x0002 10387 #define FTS5_TOKENIZE_DOCUMENT 0x0004 10388 #define FTS5_TOKENIZE_AUX 0x0008 10389 10390 /* Flags that may be passed by the tokenizer implementation back to FTS5 10391 ** as the third argument to the supplied xToken callback. */ 10392 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10393 10394 /* 10395 ** END OF CUSTOM TOKENIZERS 10396 *************************************************************************/ 10397 10398 /************************************************************************* 10399 ** FTS5 EXTENSION REGISTRATION API 10400 */ 10401 typedef struct fts5_api fts5_api; 10402 struct fts5_api { 10403 int iVersion; /* Currently always set to 2 */ 10404 10405 /* Create a new tokenizer */ 10406 int (*xCreateTokenizer)( 10407 fts5_api *pApi, 10408 const char *zName, 10409 void *pContext, 10410 fts5_tokenizer *pTokenizer, 10411 void (*xDestroy)(void*) 10412 ); 10413 10414 /* Find an existing tokenizer */ 10415 int (*xFindTokenizer)( 10416 fts5_api *pApi, 10417 const char *zName, 10418 void **ppContext, 10419 fts5_tokenizer *pTokenizer 10420 ); 10421 10422 /* Create a new auxiliary function */ 10423 int (*xCreateFunction)( 10424 fts5_api *pApi, 10425 const char *zName, 10426 void *pContext, 10427 fts5_extension_function xFunction, 10428 void (*xDestroy)(void*) 10429 ); 10430 }; 10431 10432 /* 10433 ** END OF REGISTRATION API 10434 *************************************************************************/ 10435 10436 #ifdef __cplusplus 10437 } /* end of the 'extern "C"' block */ 10438 #endif 10439 10440 #endif /* _FTS5_H */ 10441 10442 /******** End of fts5.h *********/ 10443