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 file contains C code routines that are called by the parser
13 ** to handle INSERT statements in SQLite.
14 */
15 #include "sqliteInt.h"
16 
17 /*
18 ** Generate code that will
19 **
20 **   (1) acquire a lock for table pTab then
21 **   (2) open pTab as cursor iCur.
22 **
23 ** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index
24 ** for that table that is actually opened.
25 */
sqlite3OpenTable(Parse * pParse,int iCur,int iDb,Table * pTab,int opcode)26 void sqlite3OpenTable(
27   Parse *pParse,  /* Generate code into this VDBE */
28   int iCur,       /* The cursor number of the table */
29   int iDb,        /* The database index in sqlite3.aDb[] */
30   Table *pTab,    /* The table to be opened */
31   int opcode      /* OP_OpenRead or OP_OpenWrite */
32 ){
33   Vdbe *v;
34   assert( !IsVirtual(pTab) );
35   assert( pParse->pVdbe!=0 );
36   v = pParse->pVdbe;
37   assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
38   sqlite3TableLock(pParse, iDb, pTab->tnum,
39                    (opcode==OP_OpenWrite)?1:0, pTab->zName);
40   if( HasRowid(pTab) ){
41     sqlite3VdbeAddOp4Int(v, opcode, iCur, pTab->tnum, iDb, pTab->nNVCol);
42     VdbeComment((v, "%s", pTab->zName));
43   }else{
44     Index *pPk = sqlite3PrimaryKeyIndex(pTab);
45     assert( pPk!=0 );
46     assert( pPk->tnum==pTab->tnum );
47     sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);
48     sqlite3VdbeSetP4KeyInfo(pParse, pPk);
49     VdbeComment((v, "%s", pTab->zName));
50   }
51 }
52 
53 /*
54 ** Return a pointer to the column affinity string associated with index
55 ** pIdx. A column affinity string has one character for each column in
56 ** the table, according to the affinity of the column:
57 **
58 **  Character      Column affinity
59 **  ------------------------------
60 **  'A'            BLOB
61 **  'B'            TEXT
62 **  'C'            NUMERIC
63 **  'D'            INTEGER
64 **  'F'            REAL
65 **
66 ** An extra 'D' is appended to the end of the string to cover the
67 ** rowid that appears as the last column in every index.
68 **
69 ** Memory for the buffer containing the column index affinity string
70 ** is managed along with the rest of the Index structure. It will be
71 ** released when sqlite3DeleteIndex() is called.
72 */
sqlite3IndexAffinityStr(sqlite3 * db,Index * pIdx)73 const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
74   if( !pIdx->zColAff ){
75     /* The first time a column affinity string for a particular index is
76     ** required, it is allocated and populated here. It is then stored as
77     ** a member of the Index structure for subsequent use.
78     **
79     ** The column affinity string will eventually be deleted by
80     ** sqliteDeleteIndex() when the Index structure itself is cleaned
81     ** up.
82     */
83     int n;
84     Table *pTab = pIdx->pTable;
85     pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
86     if( !pIdx->zColAff ){
87       sqlite3OomFault(db);
88       return 0;
89     }
90     for(n=0; n<pIdx->nColumn; n++){
91       i16 x = pIdx->aiColumn[n];
92       char aff;
93       if( x>=0 ){
94         aff = pTab->aCol[x].affinity;
95       }else if( x==XN_ROWID ){
96         aff = SQLITE_AFF_INTEGER;
97       }else{
98         assert( x==XN_EXPR );
99         assert( pIdx->aColExpr!=0 );
100         aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
101       }
102       if( aff<SQLITE_AFF_BLOB ) aff = SQLITE_AFF_BLOB;
103       if( aff>SQLITE_AFF_NUMERIC) aff = SQLITE_AFF_NUMERIC;
104       pIdx->zColAff[n] = aff;
105     }
106     pIdx->zColAff[n] = 0;
107   }
108 
109   return pIdx->zColAff;
110 }
111 
112 /*
113 ** Compute the affinity string for table pTab, if it has not already been
114 ** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
115 **
116 ** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and
117 ** if iReg>0 then code an OP_Affinity opcode that will set the affinities
118 ** for register iReg and following.  Or if affinities exists and iReg==0,
119 ** then just set the P4 operand of the previous opcode (which should  be
120 ** an OP_MakeRecord) to the affinity string.
121 **
122 ** A column affinity string has one character per column:
123 **
124 **  Character      Column affinity
125 **  ------------------------------
126 **  'A'            BLOB
127 **  'B'            TEXT
128 **  'C'            NUMERIC
129 **  'D'            INTEGER
130 **  'E'            REAL
131 */
sqlite3TableAffinity(Vdbe * v,Table * pTab,int iReg)132 void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
133   int i, j;
134   char *zColAff = pTab->zColAff;
135   if( zColAff==0 ){
136     sqlite3 *db = sqlite3VdbeDb(v);
137     zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
138     if( !zColAff ){
139       sqlite3OomFault(db);
140       return;
141     }
142 
143     for(i=j=0; i<pTab->nCol; i++){
144       assert( pTab->aCol[i].affinity!=0 );
145       if( (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ){
146         zColAff[j++] = pTab->aCol[i].affinity;
147       }
148     }
149     do{
150       zColAff[j--] = 0;
151     }while( j>=0 && zColAff[j]<=SQLITE_AFF_BLOB );
152     pTab->zColAff = zColAff;
153   }
154   assert( zColAff!=0 );
155   i = sqlite3Strlen30NN(zColAff);
156   if( i ){
157     if( iReg ){
158       sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);
159     }else{
160       sqlite3VdbeChangeP4(v, -1, zColAff, i);
161     }
162   }
163 }
164 
165 /*
166 ** Return non-zero if the table pTab in database iDb or any of its indices
167 ** have been opened at any point in the VDBE program. This is used to see if
168 ** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can
169 ** run without using a temporary table for the results of the SELECT.
170 */
readsTable(Parse * p,int iDb,Table * pTab)171 static int readsTable(Parse *p, int iDb, Table *pTab){
172   Vdbe *v = sqlite3GetVdbe(p);
173   int i;
174   int iEnd = sqlite3VdbeCurrentAddr(v);
175 #ifndef SQLITE_OMIT_VIRTUALTABLE
176   VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
177 #endif
178 
179   for(i=1; i<iEnd; i++){
180     VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
181     assert( pOp!=0 );
182     if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
183       Index *pIndex;
184       Pgno tnum = pOp->p2;
185       if( tnum==pTab->tnum ){
186         return 1;
187       }
188       for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
189         if( tnum==pIndex->tnum ){
190           return 1;
191         }
192       }
193     }
194 #ifndef SQLITE_OMIT_VIRTUALTABLE
195     if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){
196       assert( pOp->p4.pVtab!=0 );
197       assert( pOp->p4type==P4_VTAB );
198       return 1;
199     }
200 #endif
201   }
202   return 0;
203 }
204 
205 /* This walker callback will compute the union of colFlags flags for all
206 ** referenced columns in a CHECK constraint or generated column expression.
207 */
exprColumnFlagUnion(Walker * pWalker,Expr * pExpr)208 static int exprColumnFlagUnion(Walker *pWalker, Expr *pExpr){
209   if( pExpr->op==TK_COLUMN && pExpr->iColumn>=0 ){
210     assert( pExpr->iColumn < pWalker->u.pTab->nCol );
211     pWalker->eCode |= pWalker->u.pTab->aCol[pExpr->iColumn].colFlags;
212   }
213   return WRC_Continue;
214 }
215 
216 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
217 /*
218 ** All regular columns for table pTab have been puts into registers
219 ** starting with iRegStore.  The registers that correspond to STORED
220 ** or VIRTUAL columns have not yet been initialized.  This routine goes
221 ** back and computes the values for those columns based on the previously
222 ** computed normal columns.
223 */
sqlite3ComputeGeneratedColumns(Parse * pParse,int iRegStore,Table * pTab)224 void sqlite3ComputeGeneratedColumns(
225   Parse *pParse,    /* Parsing context */
226   int iRegStore,    /* Register holding the first column */
227   Table *pTab       /* The table */
228 ){
229   int i;
230   Walker w;
231   Column *pRedo;
232   int eProgress;
233   VdbeOp *pOp;
234 
235   assert( pTab->tabFlags & TF_HasGenerated );
236   testcase( pTab->tabFlags & TF_HasVirtual );
237   testcase( pTab->tabFlags & TF_HasStored );
238 
239   /* Before computing generated columns, first go through and make sure
240   ** that appropriate affinity has been applied to the regular columns
241   */
242   sqlite3TableAffinity(pParse->pVdbe, pTab, iRegStore);
243   if( (pTab->tabFlags & TF_HasStored)!=0
244    && (pOp = sqlite3VdbeGetOp(pParse->pVdbe,-1))->opcode==OP_Affinity
245   ){
246     /* Change the OP_Affinity argument to '@' (NONE) for all stored
247     ** columns.  '@' is the no-op affinity and those columns have not
248     ** yet been computed. */
249     int ii, jj;
250     char *zP4 = pOp->p4.z;
251     assert( zP4!=0 );
252     assert( pOp->p4type==P4_DYNAMIC );
253     for(ii=jj=0; zP4[jj]; ii++){
254       if( pTab->aCol[ii].colFlags & COLFLAG_VIRTUAL ){
255         continue;
256       }
257       if( pTab->aCol[ii].colFlags & COLFLAG_STORED ){
258         zP4[jj] = SQLITE_AFF_NONE;
259       }
260       jj++;
261     }
262   }
263 
264   /* Because there can be multiple generated columns that refer to one another,
265   ** this is a two-pass algorithm.  On the first pass, mark all generated
266   ** columns as "not available".
267   */
268   for(i=0; i<pTab->nCol; i++){
269     if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
270       testcase( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL );
271       testcase( pTab->aCol[i].colFlags & COLFLAG_STORED );
272       pTab->aCol[i].colFlags |= COLFLAG_NOTAVAIL;
273     }
274   }
275 
276   w.u.pTab = pTab;
277   w.xExprCallback = exprColumnFlagUnion;
278   w.xSelectCallback = 0;
279   w.xSelectCallback2 = 0;
280 
281   /* On the second pass, compute the value of each NOT-AVAILABLE column.
282   ** Companion code in the TK_COLUMN case of sqlite3ExprCodeTarget() will
283   ** compute dependencies and mark remove the COLSPAN_NOTAVAIL mark, as
284   ** they are needed.
285   */
286   pParse->iSelfTab = -iRegStore;
287   do{
288     eProgress = 0;
289     pRedo = 0;
290     for(i=0; i<pTab->nCol; i++){
291       Column *pCol = pTab->aCol + i;
292       if( (pCol->colFlags & COLFLAG_NOTAVAIL)!=0 ){
293         int x;
294         pCol->colFlags |= COLFLAG_BUSY;
295         w.eCode = 0;
296         sqlite3WalkExpr(&w, pCol->pDflt);
297         pCol->colFlags &= ~COLFLAG_BUSY;
298         if( w.eCode & COLFLAG_NOTAVAIL ){
299           pRedo = pCol;
300           continue;
301         }
302         eProgress = 1;
303         assert( pCol->colFlags & COLFLAG_GENERATED );
304         x = sqlite3TableColumnToStorage(pTab, i) + iRegStore;
305         sqlite3ExprCodeGeneratedColumn(pParse, pCol, x);
306         pCol->colFlags &= ~COLFLAG_NOTAVAIL;
307       }
308     }
309   }while( pRedo && eProgress );
310   if( pRedo ){
311     sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pRedo->zName);
312   }
313   pParse->iSelfTab = 0;
314 }
315 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
316 
317 
318 #ifndef SQLITE_OMIT_AUTOINCREMENT
319 /*
320 ** Locate or create an AutoincInfo structure associated with table pTab
321 ** which is in database iDb.  Return the register number for the register
322 ** that holds the maximum rowid.  Return zero if pTab is not an AUTOINCREMENT
323 ** table.  (Also return zero when doing a VACUUM since we do not want to
324 ** update the AUTOINCREMENT counters during a VACUUM.)
325 **
326 ** There is at most one AutoincInfo structure per table even if the
327 ** same table is autoincremented multiple times due to inserts within
328 ** triggers.  A new AutoincInfo structure is created if this is the
329 ** first use of table pTab.  On 2nd and subsequent uses, the original
330 ** AutoincInfo structure is used.
331 **
332 ** Four consecutive registers are allocated:
333 **
334 **   (1)  The name of the pTab table.
335 **   (2)  The maximum ROWID of pTab.
336 **   (3)  The rowid in sqlite_sequence of pTab
337 **   (4)  The original value of the max ROWID in pTab, or NULL if none
338 **
339 ** The 2nd register is the one that is returned.  That is all the
340 ** insert routine needs to know about.
341 */
autoIncBegin(Parse * pParse,int iDb,Table * pTab)342 static int autoIncBegin(
343   Parse *pParse,      /* Parsing context */
344   int iDb,            /* Index of the database holding pTab */
345   Table *pTab         /* The table we are writing to */
346 ){
347   int memId = 0;      /* Register holding maximum rowid */
348   assert( pParse->db->aDb[iDb].pSchema!=0 );
349   if( (pTab->tabFlags & TF_Autoincrement)!=0
350    && (pParse->db->mDbFlags & DBFLAG_Vacuum)==0
351   ){
352     Parse *pToplevel = sqlite3ParseToplevel(pParse);
353     AutoincInfo *pInfo;
354     Table *pSeqTab = pParse->db->aDb[iDb].pSchema->pSeqTab;
355 
356     /* Verify that the sqlite_sequence table exists and is an ordinary
357     ** rowid table with exactly two columns.
358     ** Ticket d8dc2b3a58cd5dc2918a1d4acb 2018-05-23 */
359     if( pSeqTab==0
360      || !HasRowid(pSeqTab)
361      || IsVirtual(pSeqTab)
362      || pSeqTab->nCol!=2
363     ){
364       pParse->nErr++;
365       pParse->rc = SQLITE_CORRUPT_SEQUENCE;
366       return 0;
367     }
368 
369     pInfo = pToplevel->pAinc;
370     while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
371     if( pInfo==0 ){
372       pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));
373       if( pInfo==0 ) return 0;
374       pInfo->pNext = pToplevel->pAinc;
375       pToplevel->pAinc = pInfo;
376       pInfo->pTab = pTab;
377       pInfo->iDb = iDb;
378       pToplevel->nMem++;                  /* Register to hold name of table */
379       pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */
380       pToplevel->nMem +=2;       /* Rowid in sqlite_sequence + orig max val */
381     }
382     memId = pInfo->regCtr;
383   }
384   return memId;
385 }
386 
387 /*
388 ** This routine generates code that will initialize all of the
389 ** register used by the autoincrement tracker.
390 */
sqlite3AutoincrementBegin(Parse * pParse)391 void sqlite3AutoincrementBegin(Parse *pParse){
392   AutoincInfo *p;            /* Information about an AUTOINCREMENT */
393   sqlite3 *db = pParse->db;  /* The database connection */
394   Db *pDb;                   /* Database only autoinc table */
395   int memId;                 /* Register holding max rowid */
396   Vdbe *v = pParse->pVdbe;   /* VDBE under construction */
397 
398   /* This routine is never called during trigger-generation.  It is
399   ** only called from the top-level */
400   assert( pParse->pTriggerTab==0 );
401   assert( sqlite3IsToplevel(pParse) );
402 
403   assert( v );   /* We failed long ago if this is not so */
404   for(p = pParse->pAinc; p; p = p->pNext){
405     static const int iLn = VDBE_OFFSET_LINENO(2);
406     static const VdbeOpList autoInc[] = {
407       /* 0  */ {OP_Null,    0,  0, 0},
408       /* 1  */ {OP_Rewind,  0, 10, 0},
409       /* 2  */ {OP_Column,  0,  0, 0},
410       /* 3  */ {OP_Ne,      0,  9, 0},
411       /* 4  */ {OP_Rowid,   0,  0, 0},
412       /* 5  */ {OP_Column,  0,  1, 0},
413       /* 6  */ {OP_AddImm,  0,  0, 0},
414       /* 7  */ {OP_Copy,    0,  0, 0},
415       /* 8  */ {OP_Goto,    0, 11, 0},
416       /* 9  */ {OP_Next,    0,  2, 0},
417       /* 10 */ {OP_Integer, 0,  0, 0},
418       /* 11 */ {OP_Close,   0,  0, 0}
419     };
420     VdbeOp *aOp;
421     pDb = &db->aDb[p->iDb];
422     memId = p->regCtr;
423     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
424     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
425     sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
426     aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);
427     if( aOp==0 ) break;
428     aOp[0].p2 = memId;
429     aOp[0].p3 = memId+2;
430     aOp[2].p3 = memId;
431     aOp[3].p1 = memId-1;
432     aOp[3].p3 = memId;
433     aOp[3].p5 = SQLITE_JUMPIFNULL;
434     aOp[4].p2 = memId+1;
435     aOp[5].p3 = memId;
436     aOp[6].p1 = memId;
437     aOp[7].p2 = memId+2;
438     aOp[7].p1 = memId;
439     aOp[10].p2 = memId;
440     if( pParse->nTab==0 ) pParse->nTab = 1;
441   }
442 }
443 
444 /*
445 ** Update the maximum rowid for an autoincrement calculation.
446 **
447 ** This routine should be called when the regRowid register holds a
448 ** new rowid that is about to be inserted.  If that new rowid is
449 ** larger than the maximum rowid in the memId memory cell, then the
450 ** memory cell is updated.
451 */
autoIncStep(Parse * pParse,int memId,int regRowid)452 static void autoIncStep(Parse *pParse, int memId, int regRowid){
453   if( memId>0 ){
454     sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
455   }
456 }
457 
458 /*
459 ** This routine generates the code needed to write autoincrement
460 ** maximum rowid values back into the sqlite_sequence register.
461 ** Every statement that might do an INSERT into an autoincrement
462 ** table (either directly or through triggers) needs to call this
463 ** routine just before the "exit" code.
464 */
autoIncrementEnd(Parse * pParse)465 static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){
466   AutoincInfo *p;
467   Vdbe *v = pParse->pVdbe;
468   sqlite3 *db = pParse->db;
469 
470   assert( v );
471   for(p = pParse->pAinc; p; p = p->pNext){
472     static const int iLn = VDBE_OFFSET_LINENO(2);
473     static const VdbeOpList autoIncEnd[] = {
474       /* 0 */ {OP_NotNull,     0, 2, 0},
475       /* 1 */ {OP_NewRowid,    0, 0, 0},
476       /* 2 */ {OP_MakeRecord,  0, 2, 0},
477       /* 3 */ {OP_Insert,      0, 0, 0},
478       /* 4 */ {OP_Close,       0, 0, 0}
479     };
480     VdbeOp *aOp;
481     Db *pDb = &db->aDb[p->iDb];
482     int iRec;
483     int memId = p->regCtr;
484 
485     iRec = sqlite3GetTempReg(pParse);
486     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
487     sqlite3VdbeAddOp3(v, OP_Le, memId+2, sqlite3VdbeCurrentAddr(v)+7, memId);
488     VdbeCoverage(v);
489     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
490     aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);
491     if( aOp==0 ) break;
492     aOp[0].p1 = memId+1;
493     aOp[1].p2 = memId+1;
494     aOp[2].p1 = memId-1;
495     aOp[2].p3 = iRec;
496     aOp[3].p2 = iRec;
497     aOp[3].p3 = memId+1;
498     aOp[3].p5 = OPFLAG_APPEND;
499     sqlite3ReleaseTempReg(pParse, iRec);
500   }
501 }
sqlite3AutoincrementEnd(Parse * pParse)502 void sqlite3AutoincrementEnd(Parse *pParse){
503   if( pParse->pAinc ) autoIncrementEnd(pParse);
504 }
505 #else
506 /*
507 ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
508 ** above are all no-ops
509 */
510 # define autoIncBegin(A,B,C) (0)
511 # define autoIncStep(A,B,C)
512 #endif /* SQLITE_OMIT_AUTOINCREMENT */
513 
514 
515 /* Forward declaration */
516 static int xferOptimization(
517   Parse *pParse,        /* Parser context */
518   Table *pDest,         /* The table we are inserting into */
519   Select *pSelect,      /* A SELECT statement to use as the data source */
520   int onError,          /* How to handle constraint errors */
521   int iDbDest           /* The database of pDest */
522 );
523 
524 /*
525 ** This routine is called to handle SQL of the following forms:
526 **
527 **    insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
528 **    insert into TABLE (IDLIST) select
529 **    insert into TABLE (IDLIST) default values
530 **
531 ** The IDLIST following the table name is always optional.  If omitted,
532 ** then a list of all (non-hidden) columns for the table is substituted.
533 ** The IDLIST appears in the pColumn parameter.  pColumn is NULL if IDLIST
534 ** is omitted.
535 **
536 ** For the pSelect parameter holds the values to be inserted for the
537 ** first two forms shown above.  A VALUES clause is really just short-hand
538 ** for a SELECT statement that omits the FROM clause and everything else
539 ** that follows.  If the pSelect parameter is NULL, that means that the
540 ** DEFAULT VALUES form of the INSERT statement is intended.
541 **
542 ** The code generated follows one of four templates.  For a simple
543 ** insert with data coming from a single-row VALUES clause, the code executes
544 ** once straight down through.  Pseudo-code follows (we call this
545 ** the "1st template"):
546 **
547 **         open write cursor to <table> and its indices
548 **         put VALUES clause expressions into registers
549 **         write the resulting record into <table>
550 **         cleanup
551 **
552 ** The three remaining templates assume the statement is of the form
553 **
554 **   INSERT INTO <table> SELECT ...
555 **
556 ** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
557 ** in other words if the SELECT pulls all columns from a single table
558 ** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
559 ** if <table2> and <table1> are distinct tables but have identical
560 ** schemas, including all the same indices, then a special optimization
561 ** is invoked that copies raw records from <table2> over to <table1>.
562 ** See the xferOptimization() function for the implementation of this
563 ** template.  This is the 2nd template.
564 **
565 **         open a write cursor to <table>
566 **         open read cursor on <table2>
567 **         transfer all records in <table2> over to <table>
568 **         close cursors
569 **         foreach index on <table>
570 **           open a write cursor on the <table> index
571 **           open a read cursor on the corresponding <table2> index
572 **           transfer all records from the read to the write cursors
573 **           close cursors
574 **         end foreach
575 **
576 ** The 3rd template is for when the second template does not apply
577 ** and the SELECT clause does not read from <table> at any time.
578 ** The generated code follows this template:
579 **
580 **         X <- A
581 **         goto B
582 **      A: setup for the SELECT
583 **         loop over the rows in the SELECT
584 **           load values into registers R..R+n
585 **           yield X
586 **         end loop
587 **         cleanup after the SELECT
588 **         end-coroutine X
589 **      B: open write cursor to <table> and its indices
590 **      C: yield X, at EOF goto D
591 **         insert the select result into <table> from R..R+n
592 **         goto C
593 **      D: cleanup
594 **
595 ** The 4th template is used if the insert statement takes its
596 ** values from a SELECT but the data is being inserted into a table
597 ** that is also read as part of the SELECT.  In the third form,
598 ** we have to use an intermediate table to store the results of
599 ** the select.  The template is like this:
600 **
601 **         X <- A
602 **         goto B
603 **      A: setup for the SELECT
604 **         loop over the tables in the SELECT
605 **           load value into register R..R+n
606 **           yield X
607 **         end loop
608 **         cleanup after the SELECT
609 **         end co-routine R
610 **      B: open temp table
611 **      L: yield X, at EOF goto M
612 **         insert row from R..R+n into temp table
613 **         goto L
614 **      M: open write cursor to <table> and its indices
615 **         rewind temp table
616 **      C: loop over rows of intermediate table
617 **           transfer values form intermediate table into <table>
618 **         end loop
619 **      D: cleanup
620 */
sqlite3Insert(Parse * pParse,SrcList * pTabList,Select * pSelect,IdList * pColumn,int onError,Upsert * pUpsert)621 void sqlite3Insert(
622   Parse *pParse,        /* Parser context */
623   SrcList *pTabList,    /* Name of table into which we are inserting */
624   Select *pSelect,      /* A SELECT statement to use as the data source */
625   IdList *pColumn,      /* Column names corresponding to IDLIST, or NULL. */
626   int onError,          /* How to handle constraint errors */
627   Upsert *pUpsert       /* ON CONFLICT clauses for upsert, or NULL */
628 ){
629   sqlite3 *db;          /* The main database structure */
630   Table *pTab;          /* The table to insert into.  aka TABLE */
631   int i, j;             /* Loop counters */
632   Vdbe *v;              /* Generate code into this virtual machine */
633   Index *pIdx;          /* For looping over indices of the table */
634   int nColumn;          /* Number of columns in the data */
635   int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */
636   int iDataCur = 0;     /* VDBE cursor that is the main data repository */
637   int iIdxCur = 0;      /* First index cursor */
638   int ipkColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
639   int endOfLoop;        /* Label for the end of the insertion loop */
640   int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
641   int addrInsTop = 0;   /* Jump to label "D" */
642   int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
643   SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
644   int iDb;              /* Index of database holding TABLE */
645   u8 useTempTable = 0;  /* Store SELECT results in intermediate table */
646   u8 appendFlag = 0;    /* True if the insert is likely to be an append */
647   u8 withoutRowid;      /* 0 for normal table.  1 for WITHOUT ROWID table */
648   u8 bIdListInOrder;    /* True if IDLIST is in table order */
649   ExprList *pList = 0;  /* List of VALUES() to be inserted  */
650   int iRegStore;        /* Register in which to store next column */
651 
652   /* Register allocations */
653   int regFromSelect = 0;/* Base register for data coming from SELECT */
654   int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
655   int regRowCount = 0;  /* Memory cell used for the row counter */
656   int regIns;           /* Block of regs holding rowid+data being inserted */
657   int regRowid;         /* registers holding insert rowid */
658   int regData;          /* register holding first column to insert */
659   int *aRegIdx = 0;     /* One register allocated to each index */
660 
661 #ifndef SQLITE_OMIT_TRIGGER
662   int isView;                 /* True if attempting to insert into a view */
663   Trigger *pTrigger;          /* List of triggers on pTab, if required */
664   int tmask;                  /* Mask of trigger times */
665 #endif
666 
667   db = pParse->db;
668   if( pParse->nErr || db->mallocFailed ){
669     goto insert_cleanup;
670   }
671   dest.iSDParm = 0;  /* Suppress a harmless compiler warning */
672 
673   /* If the Select object is really just a simple VALUES() list with a
674   ** single row (the common case) then keep that one row of values
675   ** and discard the other (unused) parts of the pSelect object
676   */
677   if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){
678     pList = pSelect->pEList;
679     pSelect->pEList = 0;
680     sqlite3SelectDelete(db, pSelect);
681     pSelect = 0;
682   }
683 
684   /* Locate the table into which we will be inserting new information.
685   */
686   assert( pTabList->nSrc==1 );
687   pTab = sqlite3SrcListLookup(pParse, pTabList);
688   if( pTab==0 ){
689     goto insert_cleanup;
690   }
691   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
692   assert( iDb<db->nDb );
693   if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0,
694                        db->aDb[iDb].zDbSName) ){
695     goto insert_cleanup;
696   }
697   withoutRowid = !HasRowid(pTab);
698 
699   /* Figure out if we have any triggers and if the table being
700   ** inserted into is a view
701   */
702 #ifndef SQLITE_OMIT_TRIGGER
703   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
704   isView = pTab->pSelect!=0;
705 #else
706 # define pTrigger 0
707 # define tmask 0
708 # define isView 0
709 #endif
710 #ifdef SQLITE_OMIT_VIEW
711 # undef isView
712 # define isView 0
713 #endif
714   assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );
715 
716   /* If pTab is really a view, make sure it has been initialized.
717   ** ViewGetColumnNames() is a no-op if pTab is not a view.
718   */
719   if( sqlite3ViewGetColumnNames(pParse, pTab) ){
720     goto insert_cleanup;
721   }
722 
723   /* Cannot insert into a read-only table.
724   */
725   if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
726     goto insert_cleanup;
727   }
728 
729   /* Allocate a VDBE
730   */
731   v = sqlite3GetVdbe(pParse);
732   if( v==0 ) goto insert_cleanup;
733   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
734   sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);
735 
736 #ifndef SQLITE_OMIT_XFER_OPT
737   /* If the statement is of the form
738   **
739   **       INSERT INTO <table1> SELECT * FROM <table2>;
740   **
741   ** Then special optimizations can be applied that make the transfer
742   ** very fast and which reduce fragmentation of indices.
743   **
744   ** This is the 2nd template.
745   */
746   if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
747     assert( !pTrigger );
748     assert( pList==0 );
749     goto insert_end;
750   }
751 #endif /* SQLITE_OMIT_XFER_OPT */
752 
753   /* If this is an AUTOINCREMENT table, look up the sequence number in the
754   ** sqlite_sequence table and store it in memory cell regAutoinc.
755   */
756   regAutoinc = autoIncBegin(pParse, iDb, pTab);
757 
758   /* Allocate a block registers to hold the rowid and the values
759   ** for all columns of the new row.
760   */
761   regRowid = regIns = pParse->nMem+1;
762   pParse->nMem += pTab->nCol + 1;
763   if( IsVirtual(pTab) ){
764     regRowid++;
765     pParse->nMem++;
766   }
767   regData = regRowid+1;
768 
769   /* If the INSERT statement included an IDLIST term, then make sure
770   ** all elements of the IDLIST really are columns of the table and
771   ** remember the column indices.
772   **
773   ** If the table has an INTEGER PRIMARY KEY column and that column
774   ** is named in the IDLIST, then record in the ipkColumn variable
775   ** the index into IDLIST of the primary key column.  ipkColumn is
776   ** the index of the primary key as it appears in IDLIST, not as
777   ** is appears in the original table.  (The index of the INTEGER
778   ** PRIMARY KEY in the original table is pTab->iPKey.)  After this
779   ** loop, if ipkColumn==(-1), that means that integer primary key
780   ** is unspecified, and hence the table is either WITHOUT ROWID or
781   ** it will automatically generated an integer primary key.
782   **
783   ** bIdListInOrder is true if the columns in IDLIST are in storage
784   ** order.  This enables an optimization that avoids shuffling the
785   ** columns into storage order.  False negatives are harmless,
786   ** but false positives will cause database corruption.
787   */
788   bIdListInOrder = (pTab->tabFlags & (TF_OOOHidden|TF_HasStored))==0;
789   if( pColumn ){
790     for(i=0; i<pColumn->nId; i++){
791       pColumn->a[i].idx = -1;
792     }
793     for(i=0; i<pColumn->nId; i++){
794       for(j=0; j<pTab->nCol; j++){
795         if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
796           pColumn->a[i].idx = j;
797           if( i!=j ) bIdListInOrder = 0;
798           if( j==pTab->iPKey ){
799             ipkColumn = i;  assert( !withoutRowid );
800           }
801 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
802           if( pTab->aCol[j].colFlags & (COLFLAG_STORED|COLFLAG_VIRTUAL) ){
803             sqlite3ErrorMsg(pParse,
804                "cannot INSERT into generated column \"%s\"",
805                pTab->aCol[j].zName);
806             goto insert_cleanup;
807           }
808 #endif
809           break;
810         }
811       }
812       if( j>=pTab->nCol ){
813         if( sqlite3IsRowid(pColumn->a[i].zName) && !withoutRowid ){
814           ipkColumn = i;
815           bIdListInOrder = 0;
816         }else{
817           sqlite3ErrorMsg(pParse, "table %S has no column named %s",
818               pTabList, 0, pColumn->a[i].zName);
819           pParse->checkSchema = 1;
820           goto insert_cleanup;
821         }
822       }
823     }
824   }
825 
826   /* Figure out how many columns of data are supplied.  If the data
827   ** is coming from a SELECT statement, then generate a co-routine that
828   ** produces a single row of the SELECT on each invocation.  The
829   ** co-routine is the common header to the 3rd and 4th templates.
830   */
831   if( pSelect ){
832     /* Data is coming from a SELECT or from a multi-row VALUES clause.
833     ** Generate a co-routine to run the SELECT. */
834     int regYield;       /* Register holding co-routine entry-point */
835     int addrTop;        /* Top of the co-routine */
836     int rc;             /* Result code */
837 
838     regYield = ++pParse->nMem;
839     addrTop = sqlite3VdbeCurrentAddr(v) + 1;
840     sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
841     sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
842     dest.iSdst = bIdListInOrder ? regData : 0;
843     dest.nSdst = pTab->nCol;
844     rc = sqlite3Select(pParse, pSelect, &dest);
845     regFromSelect = dest.iSdst;
846     if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;
847     sqlite3VdbeEndCoroutine(v, regYield);
848     sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */
849     assert( pSelect->pEList );
850     nColumn = pSelect->pEList->nExpr;
851 
852     /* Set useTempTable to TRUE if the result of the SELECT statement
853     ** should be written into a temporary table (template 4).  Set to
854     ** FALSE if each output row of the SELECT can be written directly into
855     ** the destination table (template 3).
856     **
857     ** A temp table must be used if the table being updated is also one
858     ** of the tables being read by the SELECT statement.  Also use a
859     ** temp table in the case of row triggers.
860     */
861     if( pTrigger || readsTable(pParse, iDb, pTab) ){
862       useTempTable = 1;
863     }
864 
865     if( useTempTable ){
866       /* Invoke the coroutine to extract information from the SELECT
867       ** and add it to a transient table srcTab.  The code generated
868       ** here is from the 4th template:
869       **
870       **      B: open temp table
871       **      L: yield X, goto M at EOF
872       **         insert row from R..R+n into temp table
873       **         goto L
874       **      M: ...
875       */
876       int regRec;          /* Register to hold packed record */
877       int regTempRowid;    /* Register to hold temp table ROWID */
878       int addrL;           /* Label "L" */
879 
880       srcTab = pParse->nTab++;
881       regRec = sqlite3GetTempReg(pParse);
882       regTempRowid = sqlite3GetTempReg(pParse);
883       sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
884       addrL = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); VdbeCoverage(v);
885       sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
886       sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
887       sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
888       sqlite3VdbeGoto(v, addrL);
889       sqlite3VdbeJumpHere(v, addrL);
890       sqlite3ReleaseTempReg(pParse, regRec);
891       sqlite3ReleaseTempReg(pParse, regTempRowid);
892     }
893   }else{
894     /* This is the case if the data for the INSERT is coming from a
895     ** single-row VALUES clause
896     */
897     NameContext sNC;
898     memset(&sNC, 0, sizeof(sNC));
899     sNC.pParse = pParse;
900     srcTab = -1;
901     assert( useTempTable==0 );
902     if( pList ){
903       nColumn = pList->nExpr;
904       if( sqlite3ResolveExprListNames(&sNC, pList) ){
905         goto insert_cleanup;
906       }
907     }else{
908       nColumn = 0;
909     }
910   }
911 
912   /* If there is no IDLIST term but the table has an integer primary
913   ** key, the set the ipkColumn variable to the integer primary key
914   ** column index in the original table definition.
915   */
916   if( pColumn==0 && nColumn>0 ){
917     ipkColumn = pTab->iPKey;
918 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
919     if( ipkColumn>=0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
920       testcase( pTab->tabFlags & TF_HasVirtual );
921       testcase( pTab->tabFlags & TF_HasStored );
922       for(i=ipkColumn-1; i>=0; i--){
923         if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
924           testcase( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL );
925           testcase( pTab->aCol[i].colFlags & COLFLAG_STORED );
926           ipkColumn--;
927         }
928       }
929     }
930 #endif
931   }
932 
933   /* Make sure the number of columns in the source data matches the number
934   ** of columns to be inserted into the table.
935   */
936   for(i=0; i<pTab->nCol; i++){
937     if( pTab->aCol[i].colFlags & COLFLAG_NOINSERT ) nHidden++;
938   }
939   if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
940     sqlite3ErrorMsg(pParse,
941        "table %S has %d columns but %d values were supplied",
942        pTabList, 0, pTab->nCol-nHidden, nColumn);
943     goto insert_cleanup;
944   }
945   if( pColumn!=0 && nColumn!=pColumn->nId ){
946     sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
947     goto insert_cleanup;
948   }
949 
950   /* Initialize the count of rows to be inserted
951   */
952   if( (db->flags & SQLITE_CountRows)!=0
953    && !pParse->nested
954    && !pParse->pTriggerTab
955   ){
956     regRowCount = ++pParse->nMem;
957     sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
958   }
959 
960   /* If this is not a view, open the table and and all indices */
961   if( !isView ){
962     int nIdx;
963     nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
964                                       &iDataCur, &iIdxCur);
965     aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+2));
966     if( aRegIdx==0 ){
967       goto insert_cleanup;
968     }
969     for(i=0, pIdx=pTab->pIndex; i<nIdx; pIdx=pIdx->pNext, i++){
970       assert( pIdx );
971       aRegIdx[i] = ++pParse->nMem;
972       pParse->nMem += pIdx->nColumn;
973     }
974     aRegIdx[i] = ++pParse->nMem;  /* Register to store the table record */
975   }
976 #ifndef SQLITE_OMIT_UPSERT
977   if( pUpsert ){
978     if( IsVirtual(pTab) ){
979       sqlite3ErrorMsg(pParse, "UPSERT not implemented for virtual table \"%s\"",
980               pTab->zName);
981       goto insert_cleanup;
982     }
983     if( pTab->pSelect ){
984       sqlite3ErrorMsg(pParse, "cannot UPSERT a view");
985       goto insert_cleanup;
986     }
987     if( sqlite3HasExplicitNulls(pParse, pUpsert->pUpsertTarget) ){
988       goto insert_cleanup;
989     }
990     pTabList->a[0].iCursor = iDataCur;
991     pUpsert->pUpsertSrc = pTabList;
992     pUpsert->regData = regData;
993     pUpsert->iDataCur = iDataCur;
994     pUpsert->iIdxCur = iIdxCur;
995     if( pUpsert->pUpsertTarget ){
996       sqlite3UpsertAnalyzeTarget(pParse, pTabList, pUpsert);
997     }
998   }
999 #endif
1000 
1001 
1002   /* This is the top of the main insertion loop */
1003   if( useTempTable ){
1004     /* This block codes the top of loop only.  The complete loop is the
1005     ** following pseudocode (template 4):
1006     **
1007     **         rewind temp table, if empty goto D
1008     **      C: loop over rows of intermediate table
1009     **           transfer values form intermediate table into <table>
1010     **         end loop
1011     **      D: ...
1012     */
1013     addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab); VdbeCoverage(v);
1014     addrCont = sqlite3VdbeCurrentAddr(v);
1015   }else if( pSelect ){
1016     /* This block codes the top of loop only.  The complete loop is the
1017     ** following pseudocode (template 3):
1018     **
1019     **      C: yield X, at EOF goto D
1020     **         insert the select result into <table> from R..R+n
1021     **         goto C
1022     **      D: ...
1023     */
1024     sqlite3VdbeReleaseRegisters(pParse, regData, pTab->nCol, 0, 0);
1025     addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
1026     VdbeCoverage(v);
1027     if( ipkColumn>=0 ){
1028       /* tag-20191021-001: If the INTEGER PRIMARY KEY is being generated by the
1029       ** SELECT, go ahead and copy the value into the rowid slot now, so that
1030       ** the value does not get overwritten by a NULL at tag-20191021-002. */
1031       sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
1032     }
1033   }
1034 
1035   /* Compute data for ordinary columns of the new entry.  Values
1036   ** are written in storage order into registers starting with regData.
1037   ** Only ordinary columns are computed in this loop. The rowid
1038   ** (if there is one) is computed later and generated columns are
1039   ** computed after the rowid since they might depend on the value
1040   ** of the rowid.
1041   */
1042   nHidden = 0;
1043   iRegStore = regData;  assert( regData==regRowid+1 );
1044   for(i=0; i<pTab->nCol; i++, iRegStore++){
1045     int k;
1046     u32 colFlags;
1047     assert( i>=nHidden );
1048     if( i==pTab->iPKey ){
1049       /* tag-20191021-002: References to the INTEGER PRIMARY KEY are filled
1050       ** using the rowid. So put a NULL in the IPK slot of the record to avoid
1051       ** using excess space.  The file format definition requires this extra
1052       ** NULL - we cannot optimize further by skipping the column completely */
1053       sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
1054       continue;
1055     }
1056     if( ((colFlags = pTab->aCol[i].colFlags) & COLFLAG_NOINSERT)!=0 ){
1057       nHidden++;
1058       if( (colFlags & COLFLAG_VIRTUAL)!=0 ){
1059         /* Virtual columns do not participate in OP_MakeRecord.  So back up
1060         ** iRegStore by one slot to compensate for the iRegStore++ in the
1061         ** outer for() loop */
1062         iRegStore--;
1063         continue;
1064       }else if( (colFlags & COLFLAG_STORED)!=0 ){
1065         /* Stored columns are computed later.  But if there are BEFORE
1066         ** triggers, the slots used for stored columns will be OP_Copy-ed
1067         ** to a second block of registers, so the register needs to be
1068         ** initialized to NULL to avoid an uninitialized register read */
1069         if( tmask & TRIGGER_BEFORE ){
1070           sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
1071         }
1072         continue;
1073       }else if( pColumn==0 ){
1074         /* Hidden columns that are not explicitly named in the INSERT
1075         ** get there default value */
1076         sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
1077         continue;
1078       }
1079     }
1080     if( pColumn ){
1081       for(j=0; j<pColumn->nId && pColumn->a[j].idx!=i; j++){}
1082       if( j>=pColumn->nId ){
1083         /* A column not named in the insert column list gets its
1084         ** default value */
1085         sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
1086         continue;
1087       }
1088       k = j;
1089     }else if( nColumn==0 ){
1090       /* This is INSERT INTO ... DEFAULT VALUES.  Load the default value. */
1091       sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
1092       continue;
1093     }else{
1094       k = i - nHidden;
1095     }
1096 
1097     if( useTempTable ){
1098       sqlite3VdbeAddOp3(v, OP_Column, srcTab, k, iRegStore);
1099     }else if( pSelect ){
1100       if( regFromSelect!=regData ){
1101         sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+k, iRegStore);
1102       }
1103     }else{
1104       sqlite3ExprCode(pParse, pList->a[k].pExpr, iRegStore);
1105     }
1106   }
1107 
1108 
1109   /* Run the BEFORE and INSTEAD OF triggers, if there are any
1110   */
1111   endOfLoop = sqlite3VdbeMakeLabel(pParse);
1112   if( tmask & TRIGGER_BEFORE ){
1113     int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);
1114 
1115     /* build the NEW.* reference row.  Note that if there is an INTEGER
1116     ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
1117     ** translated into a unique ID for the row.  But on a BEFORE trigger,
1118     ** we do not know what the unique ID will be (because the insert has
1119     ** not happened yet) so we substitute a rowid of -1
1120     */
1121     if( ipkColumn<0 ){
1122       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
1123     }else{
1124       int addr1;
1125       assert( !withoutRowid );
1126       if( useTempTable ){
1127         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);
1128       }else{
1129         assert( pSelect==0 );  /* Otherwise useTempTable is true */
1130         sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);
1131       }
1132       addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
1133       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
1134       sqlite3VdbeJumpHere(v, addr1);
1135       sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
1136     }
1137 
1138     /* Cannot have triggers on a virtual table. If it were possible,
1139     ** this block would have to account for hidden column.
1140     */
1141     assert( !IsVirtual(pTab) );
1142 
1143     /* Copy the new data already generated. */
1144     assert( pTab->nNVCol>0 );
1145     sqlite3VdbeAddOp3(v, OP_Copy, regRowid+1, regCols+1, pTab->nNVCol-1);
1146 
1147 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
1148     /* Compute the new value for generated columns after all other
1149     ** columns have already been computed.  This must be done after
1150     ** computing the ROWID in case one of the generated columns
1151     ** refers to the ROWID. */
1152     if( pTab->tabFlags & TF_HasGenerated ){
1153       testcase( pTab->tabFlags & TF_HasVirtual );
1154       testcase( pTab->tabFlags & TF_HasStored );
1155       sqlite3ComputeGeneratedColumns(pParse, regCols+1, pTab);
1156     }
1157 #endif
1158 
1159     /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
1160     ** do not attempt any conversions before assembling the record.
1161     ** If this is a real table, attempt conversions as required by the
1162     ** table column affinities.
1163     */
1164     if( !isView ){
1165       sqlite3TableAffinity(v, pTab, regCols+1);
1166     }
1167 
1168     /* Fire BEFORE or INSTEAD OF triggers */
1169     sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE,
1170         pTab, regCols-pTab->nCol-1, onError, endOfLoop);
1171 
1172     sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
1173   }
1174 
1175   if( !isView ){
1176     if( IsVirtual(pTab) ){
1177       /* The row that the VUpdate opcode will delete: none */
1178       sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
1179     }
1180     if( ipkColumn>=0 ){
1181       /* Compute the new rowid */
1182       if( useTempTable ){
1183         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
1184       }else if( pSelect ){
1185         /* Rowid already initialized at tag-20191021-001 */
1186       }else{
1187         Expr *pIpk = pList->a[ipkColumn].pExpr;
1188         if( pIpk->op==TK_NULL && !IsVirtual(pTab) ){
1189           sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
1190           appendFlag = 1;
1191         }else{
1192           sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
1193         }
1194       }
1195       /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
1196       ** to generate a unique primary key value.
1197       */
1198       if( !appendFlag ){
1199         int addr1;
1200         if( !IsVirtual(pTab) ){
1201           addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
1202           sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
1203           sqlite3VdbeJumpHere(v, addr1);
1204         }else{
1205           addr1 = sqlite3VdbeCurrentAddr(v);
1206           sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);
1207         }
1208         sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);
1209       }
1210     }else if( IsVirtual(pTab) || withoutRowid ){
1211       sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
1212     }else{
1213       sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
1214       appendFlag = 1;
1215     }
1216     autoIncStep(pParse, regAutoinc, regRowid);
1217 
1218 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
1219     /* Compute the new value for generated columns after all other
1220     ** columns have already been computed.  This must be done after
1221     ** computing the ROWID in case one of the generated columns
1222     ** is derived from the INTEGER PRIMARY KEY. */
1223     if( pTab->tabFlags & TF_HasGenerated ){
1224       sqlite3ComputeGeneratedColumns(pParse, regRowid+1, pTab);
1225     }
1226 #endif
1227 
1228     /* Generate code to check constraints and generate index keys and
1229     ** do the insertion.
1230     */
1231 #ifndef SQLITE_OMIT_VIRTUALTABLE
1232     if( IsVirtual(pTab) ){
1233       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
1234       sqlite3VtabMakeWritable(pParse, pTab);
1235       sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
1236       sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
1237       sqlite3MayAbort(pParse);
1238     }else
1239 #endif
1240     {
1241       int isReplace;    /* Set to true if constraints may cause a replace */
1242       int bUseSeek;     /* True to use OPFLAG_SEEKRESULT */
1243       sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
1244           regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0, pUpsert
1245       );
1246       sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
1247 
1248       /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
1249       ** constraints or (b) there are no triggers and this table is not a
1250       ** parent table in a foreign key constraint. It is safe to set the
1251       ** flag in the second case as if any REPLACE constraint is hit, an
1252       ** OP_Delete or OP_IdxDelete instruction will be executed on each
1253       ** cursor that is disturbed. And these instructions both clear the
1254       ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
1255       ** functionality.  */
1256       bUseSeek = (isReplace==0 || !sqlite3VdbeHasSubProgram(v));
1257       sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
1258           regIns, aRegIdx, 0, appendFlag, bUseSeek
1259       );
1260     }
1261   }
1262 
1263   /* Update the count of rows that are inserted
1264   */
1265   if( regRowCount ){
1266     sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
1267   }
1268 
1269   if( pTrigger ){
1270     /* Code AFTER triggers */
1271     sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER,
1272         pTab, regData-2-pTab->nCol, onError, endOfLoop);
1273   }
1274 
1275   /* The bottom of the main insertion loop, if the data source
1276   ** is a SELECT statement.
1277   */
1278   sqlite3VdbeResolveLabel(v, endOfLoop);
1279   if( useTempTable ){
1280     sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont); VdbeCoverage(v);
1281     sqlite3VdbeJumpHere(v, addrInsTop);
1282     sqlite3VdbeAddOp1(v, OP_Close, srcTab);
1283   }else if( pSelect ){
1284     sqlite3VdbeGoto(v, addrCont);
1285 #ifdef SQLITE_DEBUG
1286     /* If we are jumping back to an OP_Yield that is preceded by an
1287     ** OP_ReleaseReg, set the p5 flag on the OP_Goto so that the
1288     ** OP_ReleaseReg will be included in the loop. */
1289     if( sqlite3VdbeGetOp(v, addrCont-1)->opcode==OP_ReleaseReg ){
1290       assert( sqlite3VdbeGetOp(v, addrCont)->opcode==OP_Yield );
1291       sqlite3VdbeChangeP5(v, 1);
1292     }
1293 #endif
1294     sqlite3VdbeJumpHere(v, addrInsTop);
1295   }
1296 
1297 insert_end:
1298   /* Update the sqlite_sequence table by storing the content of the
1299   ** maximum rowid counter values recorded while inserting into
1300   ** autoincrement tables.
1301   */
1302   if( pParse->nested==0 && pParse->pTriggerTab==0 ){
1303     sqlite3AutoincrementEnd(pParse);
1304   }
1305 
1306   /*
1307   ** Return the number of rows inserted. If this routine is
1308   ** generating code because of a call to sqlite3NestedParse(), do not
1309   ** invoke the callback function.
1310   */
1311   if( regRowCount ){
1312     sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
1313     sqlite3VdbeSetNumCols(v, 1);
1314     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", SQLITE_STATIC);
1315   }
1316 
1317 insert_cleanup:
1318   sqlite3SrcListDelete(db, pTabList);
1319   sqlite3ExprListDelete(db, pList);
1320   sqlite3UpsertDelete(db, pUpsert);
1321   sqlite3SelectDelete(db, pSelect);
1322   sqlite3IdListDelete(db, pColumn);
1323   sqlite3DbFree(db, aRegIdx);
1324 }
1325 
1326 /* Make sure "isView" and other macros defined above are undefined. Otherwise
1327 ** they may interfere with compilation of other functions in this file
1328 ** (or in another file, if this file becomes part of the amalgamation).  */
1329 #ifdef isView
1330  #undef isView
1331 #endif
1332 #ifdef pTrigger
1333  #undef pTrigger
1334 #endif
1335 #ifdef tmask
1336  #undef tmask
1337 #endif
1338 
1339 /*
1340 ** Meanings of bits in of pWalker->eCode for
1341 ** sqlite3ExprReferencesUpdatedColumn()
1342 */
1343 #define CKCNSTRNT_COLUMN   0x01    /* CHECK constraint uses a changing column */
1344 #define CKCNSTRNT_ROWID    0x02    /* CHECK constraint references the ROWID */
1345 
1346 /* This is the Walker callback from sqlite3ExprReferencesUpdatedColumn().
1347 *  Set bit 0x01 of pWalker->eCode if pWalker->eCode to 0 and if this
1348 ** expression node references any of the
1349 ** columns that are being modifed by an UPDATE statement.
1350 */
checkConstraintExprNode(Walker * pWalker,Expr * pExpr)1351 static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
1352   if( pExpr->op==TK_COLUMN ){
1353     assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );
1354     if( pExpr->iColumn>=0 ){
1355       if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){
1356         pWalker->eCode |= CKCNSTRNT_COLUMN;
1357       }
1358     }else{
1359       pWalker->eCode |= CKCNSTRNT_ROWID;
1360     }
1361   }
1362   return WRC_Continue;
1363 }
1364 
1365 /*
1366 ** pExpr is a CHECK constraint on a row that is being UPDATE-ed.  The
1367 ** only columns that are modified by the UPDATE are those for which
1368 ** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
1369 **
1370 ** Return true if CHECK constraint pExpr uses any of the
1371 ** changing columns (or the rowid if it is changing).  In other words,
1372 ** return true if this CHECK constraint must be validated for
1373 ** the new row in the UPDATE statement.
1374 **
1375 ** 2018-09-15: pExpr might also be an expression for an index-on-expressions.
1376 ** The operation of this routine is the same - return true if an only if
1377 ** the expression uses one or more of columns identified by the second and
1378 ** third arguments.
1379 */
sqlite3ExprReferencesUpdatedColumn(Expr * pExpr,int * aiChng,int chngRowid)1380 int sqlite3ExprReferencesUpdatedColumn(
1381   Expr *pExpr,    /* The expression to be checked */
1382   int *aiChng,    /* aiChng[x]>=0 if column x changed by the UPDATE */
1383   int chngRowid   /* True if UPDATE changes the rowid */
1384 ){
1385   Walker w;
1386   memset(&w, 0, sizeof(w));
1387   w.eCode = 0;
1388   w.xExprCallback = checkConstraintExprNode;
1389   w.u.aiCol = aiChng;
1390   sqlite3WalkExpr(&w, pExpr);
1391   if( !chngRowid ){
1392     testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );
1393     w.eCode &= ~CKCNSTRNT_ROWID;
1394   }
1395   testcase( w.eCode==0 );
1396   testcase( w.eCode==CKCNSTRNT_COLUMN );
1397   testcase( w.eCode==CKCNSTRNT_ROWID );
1398   testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );
1399   return w.eCode!=0;
1400 }
1401 
1402 /*
1403 ** Generate code to do constraint checks prior to an INSERT or an UPDATE
1404 ** on table pTab.
1405 **
1406 ** The regNewData parameter is the first register in a range that contains
1407 ** the data to be inserted or the data after the update.  There will be
1408 ** pTab->nCol+1 registers in this range.  The first register (the one
1409 ** that regNewData points to) will contain the new rowid, or NULL in the
1410 ** case of a WITHOUT ROWID table.  The second register in the range will
1411 ** contain the content of the first table column.  The third register will
1412 ** contain the content of the second table column.  And so forth.
1413 **
1414 ** The regOldData parameter is similar to regNewData except that it contains
1415 ** the data prior to an UPDATE rather than afterwards.  regOldData is zero
1416 ** for an INSERT.  This routine can distinguish between UPDATE and INSERT by
1417 ** checking regOldData for zero.
1418 **
1419 ** For an UPDATE, the pkChng boolean is true if the true primary key (the
1420 ** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
1421 ** might be modified by the UPDATE.  If pkChng is false, then the key of
1422 ** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
1423 **
1424 ** For an INSERT, the pkChng boolean indicates whether or not the rowid
1425 ** was explicitly specified as part of the INSERT statement.  If pkChng
1426 ** is zero, it means that the either rowid is computed automatically or
1427 ** that the table is a WITHOUT ROWID table and has no rowid.  On an INSERT,
1428 ** pkChng will only be true if the INSERT statement provides an integer
1429 ** value for either the rowid column or its INTEGER PRIMARY KEY alias.
1430 **
1431 ** The code generated by this routine will store new index entries into
1432 ** registers identified by aRegIdx[].  No index entry is created for
1433 ** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
1434 ** the same as the order of indices on the linked list of indices
1435 ** at pTab->pIndex.
1436 **
1437 ** (2019-05-07) The generated code also creates a new record for the
1438 ** main table, if pTab is a rowid table, and stores that record in the
1439 ** register identified by aRegIdx[nIdx] - in other words in the first
1440 ** entry of aRegIdx[] past the last index.  It is important that the
1441 ** record be generated during constraint checks to avoid affinity changes
1442 ** to the register content that occur after constraint checks but before
1443 ** the new record is inserted.
1444 **
1445 ** The caller must have already opened writeable cursors on the main
1446 ** table and all applicable indices (that is to say, all indices for which
1447 ** aRegIdx[] is not zero).  iDataCur is the cursor for the main table when
1448 ** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
1449 ** index when operating on a WITHOUT ROWID table.  iIdxCur is the cursor
1450 ** for the first index in the pTab->pIndex list.  Cursors for other indices
1451 ** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
1452 **
1453 ** This routine also generates code to check constraints.  NOT NULL,
1454 ** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
1455 ** then the appropriate action is performed.  There are five possible
1456 ** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
1457 **
1458 **  Constraint type  Action       What Happens
1459 **  ---------------  ----------   ----------------------------------------
1460 **  any              ROLLBACK     The current transaction is rolled back and
1461 **                                sqlite3_step() returns immediately with a
1462 **                                return code of SQLITE_CONSTRAINT.
1463 **
1464 **  any              ABORT        Back out changes from the current command
1465 **                                only (do not do a complete rollback) then
1466 **                                cause sqlite3_step() to return immediately
1467 **                                with SQLITE_CONSTRAINT.
1468 **
1469 **  any              FAIL         Sqlite3_step() returns immediately with a
1470 **                                return code of SQLITE_CONSTRAINT.  The
1471 **                                transaction is not rolled back and any
1472 **                                changes to prior rows are retained.
1473 **
1474 **  any              IGNORE       The attempt in insert or update the current
1475 **                                row is skipped, without throwing an error.
1476 **                                Processing continues with the next row.
1477 **                                (There is an immediate jump to ignoreDest.)
1478 **
1479 **  NOT NULL         REPLACE      The NULL value is replace by the default
1480 **                                value for that column.  If the default value
1481 **                                is NULL, the action is the same as ABORT.
1482 **
1483 **  UNIQUE           REPLACE      The other row that conflicts with the row
1484 **                                being inserted is removed.
1485 **
1486 **  CHECK            REPLACE      Illegal.  The results in an exception.
1487 **
1488 ** Which action to take is determined by the overrideError parameter.
1489 ** Or if overrideError==OE_Default, then the pParse->onError parameter
1490 ** is used.  Or if pParse->onError==OE_Default then the onError value
1491 ** for the constraint is used.
1492 */
sqlite3GenerateConstraintChecks(Parse * pParse,Table * pTab,int * aRegIdx,int iDataCur,int iIdxCur,int regNewData,int regOldData,u8 pkChng,u8 overrideError,int ignoreDest,int * pbMayReplace,int * aiChng,Upsert * pUpsert)1493 void sqlite3GenerateConstraintChecks(
1494   Parse *pParse,       /* The parser context */
1495   Table *pTab,         /* The table being inserted or updated */
1496   int *aRegIdx,        /* Use register aRegIdx[i] for index i.  0 for unused */
1497   int iDataCur,        /* Canonical data cursor (main table or PK index) */
1498   int iIdxCur,         /* First index cursor */
1499   int regNewData,      /* First register in a range holding values to insert */
1500   int regOldData,      /* Previous content.  0 for INSERTs */
1501   u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */
1502   u8 overrideError,    /* Override onError to this if not OE_Default */
1503   int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
1504   int *pbMayReplace,   /* OUT: Set to true if constraint may cause a replace */
1505   int *aiChng,         /* column i is unchanged if aiChng[i]<0 */
1506   Upsert *pUpsert      /* ON CONFLICT clauses, if any.  NULL otherwise */
1507 ){
1508   Vdbe *v;             /* VDBE under constrution */
1509   Index *pIdx;         /* Pointer to one of the indices */
1510   Index *pPk = 0;      /* The PRIMARY KEY index */
1511   sqlite3 *db;         /* Database connection */
1512   int i;               /* loop counter */
1513   int ix;              /* Index loop counter */
1514   int nCol;            /* Number of columns */
1515   int onError;         /* Conflict resolution strategy */
1516   int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
1517   int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
1518   Index *pUpIdx = 0;   /* Index to which to apply the upsert */
1519   u8 isUpdate;         /* True if this is an UPDATE operation */
1520   u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
1521   int upsertBypass = 0;  /* Address of Goto to bypass upsert subroutine */
1522   int upsertJump = 0;    /* Address of Goto that jumps into upsert subroutine */
1523   int ipkTop = 0;        /* Top of the IPK uniqueness check */
1524   int ipkBottom = 0;     /* OP_Goto at the end of the IPK uniqueness check */
1525   /* Variables associated with retesting uniqueness constraints after
1526   ** replace triggers fire have run */
1527   int regTrigCnt;       /* Register used to count replace trigger invocations */
1528   int addrRecheck = 0;  /* Jump here to recheck all uniqueness constraints */
1529   int lblRecheckOk = 0; /* Each recheck jumps to this label if it passes */
1530   Trigger *pTrigger;    /* List of DELETE triggers on the table pTab */
1531   int nReplaceTrig = 0; /* Number of replace triggers coded */
1532 
1533   isUpdate = regOldData!=0;
1534   db = pParse->db;
1535   v = pParse->pVdbe;
1536   assert( v!=0 );
1537   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
1538   nCol = pTab->nCol;
1539 
1540   /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
1541   ** normal rowid tables.  nPkField is the number of key fields in the
1542   ** pPk index or 1 for a rowid table.  In other words, nPkField is the
1543   ** number of fields in the true primary key of the table. */
1544   if( HasRowid(pTab) ){
1545     pPk = 0;
1546     nPkField = 1;
1547   }else{
1548     pPk = sqlite3PrimaryKeyIndex(pTab);
1549     nPkField = pPk->nKeyCol;
1550   }
1551 
1552   /* Record that this module has started */
1553   VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
1554                      iDataCur, iIdxCur, regNewData, regOldData, pkChng));
1555 
1556   /* Test all NOT NULL constraints.
1557   */
1558   if( pTab->tabFlags & TF_HasNotNull ){
1559     int b2ndPass = 0;         /* True if currently running 2nd pass */
1560     int nSeenReplace = 0;     /* Number of ON CONFLICT REPLACE operations */
1561     int nGenerated = 0;       /* Number of generated columns with NOT NULL */
1562     while(1){  /* Make 2 passes over columns. Exit loop via "break" */
1563       for(i=0; i<nCol; i++){
1564         int iReg;                        /* Register holding column value */
1565         Column *pCol = &pTab->aCol[i];   /* The column to check for NOT NULL */
1566         int isGenerated;                 /* non-zero if column is generated */
1567         onError = pCol->notNull;
1568         if( onError==OE_None ) continue; /* No NOT NULL on this column */
1569         if( i==pTab->iPKey ){
1570           continue;        /* ROWID is never NULL */
1571         }
1572         isGenerated = pCol->colFlags & COLFLAG_GENERATED;
1573         if( isGenerated && !b2ndPass ){
1574           nGenerated++;
1575           continue;        /* Generated columns processed on 2nd pass */
1576         }
1577         if( aiChng && aiChng[i]<0 && !isGenerated ){
1578           /* Do not check NOT NULL on columns that do not change */
1579           continue;
1580         }
1581         if( overrideError!=OE_Default ){
1582           onError = overrideError;
1583         }else if( onError==OE_Default ){
1584           onError = OE_Abort;
1585         }
1586         if( onError==OE_Replace ){
1587           if( b2ndPass        /* REPLACE becomes ABORT on the 2nd pass */
1588            || pCol->pDflt==0  /* REPLACE is ABORT if no DEFAULT value */
1589           ){
1590             testcase( pCol->colFlags & COLFLAG_VIRTUAL );
1591             testcase( pCol->colFlags & COLFLAG_STORED );
1592             testcase( pCol->colFlags & COLFLAG_GENERATED );
1593             onError = OE_Abort;
1594           }else{
1595             assert( !isGenerated );
1596           }
1597         }else if( b2ndPass && !isGenerated ){
1598           continue;
1599         }
1600         assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1601             || onError==OE_Ignore || onError==OE_Replace );
1602         testcase( i!=sqlite3TableColumnToStorage(pTab, i) );
1603         iReg = sqlite3TableColumnToStorage(pTab, i) + regNewData + 1;
1604         switch( onError ){
1605           case OE_Replace: {
1606             int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, iReg);
1607             VdbeCoverage(v);
1608             assert( (pCol->colFlags & COLFLAG_GENERATED)==0 );
1609             nSeenReplace++;
1610             sqlite3ExprCodeCopy(pParse, pCol->pDflt, iReg);
1611             sqlite3VdbeJumpHere(v, addr1);
1612             break;
1613           }
1614           case OE_Abort:
1615             sqlite3MayAbort(pParse);
1616             /* no break */ deliberate_fall_through
1617           case OE_Rollback:
1618           case OE_Fail: {
1619             char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
1620                                         pCol->zName);
1621             sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL,
1622                               onError, iReg);
1623             sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);
1624             sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
1625             VdbeCoverage(v);
1626             break;
1627           }
1628           default: {
1629             assert( onError==OE_Ignore );
1630             sqlite3VdbeAddOp2(v, OP_IsNull, iReg, ignoreDest);
1631             VdbeCoverage(v);
1632             break;
1633           }
1634         } /* end switch(onError) */
1635       } /* end loop i over columns */
1636       if( nGenerated==0 && nSeenReplace==0 ){
1637         /* If there are no generated columns with NOT NULL constraints
1638         ** and no NOT NULL ON CONFLICT REPLACE constraints, then a single
1639         ** pass is sufficient */
1640         break;
1641       }
1642       if( b2ndPass ) break;  /* Never need more than 2 passes */
1643       b2ndPass = 1;
1644 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
1645       if( nSeenReplace>0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
1646         /* If any NOT NULL ON CONFLICT REPLACE constraints fired on the
1647         ** first pass, recomputed values for all generated columns, as
1648         ** those values might depend on columns affected by the REPLACE.
1649         */
1650         sqlite3ComputeGeneratedColumns(pParse, regNewData+1, pTab);
1651       }
1652 #endif
1653     } /* end of 2-pass loop */
1654   } /* end if( has-not-null-constraints ) */
1655 
1656   /* Test all CHECK constraints
1657   */
1658 #ifndef SQLITE_OMIT_CHECK
1659   if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
1660     ExprList *pCheck = pTab->pCheck;
1661     pParse->iSelfTab = -(regNewData+1);
1662     onError = overrideError!=OE_Default ? overrideError : OE_Abort;
1663     for(i=0; i<pCheck->nExpr; i++){
1664       int allOk;
1665       Expr *pCopy;
1666       Expr *pExpr = pCheck->a[i].pExpr;
1667       if( aiChng
1668        && !sqlite3ExprReferencesUpdatedColumn(pExpr, aiChng, pkChng)
1669       ){
1670         /* The check constraints do not reference any of the columns being
1671         ** updated so there is no point it verifying the check constraint */
1672         continue;
1673       }
1674       if( bAffinityDone==0 ){
1675         sqlite3TableAffinity(v, pTab, regNewData+1);
1676         bAffinityDone = 1;
1677       }
1678       allOk = sqlite3VdbeMakeLabel(pParse);
1679       sqlite3VdbeVerifyAbortable(v, onError);
1680       pCopy = sqlite3ExprDup(db, pExpr, 0);
1681       if( !db->mallocFailed ){
1682         sqlite3ExprIfTrue(pParse, pCopy, allOk, SQLITE_JUMPIFNULL);
1683       }
1684       sqlite3ExprDelete(db, pCopy);
1685       if( onError==OE_Ignore ){
1686         sqlite3VdbeGoto(v, ignoreDest);
1687       }else{
1688         char *zName = pCheck->a[i].zEName;
1689         assert( zName!=0 || pParse->db->mallocFailed );
1690         if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */
1691         sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
1692                               onError, zName, P4_TRANSIENT,
1693                               P5_ConstraintCheck);
1694       }
1695       sqlite3VdbeResolveLabel(v, allOk);
1696     }
1697     pParse->iSelfTab = 0;
1698   }
1699 #endif /* !defined(SQLITE_OMIT_CHECK) */
1700 
1701   /* UNIQUE and PRIMARY KEY constraints should be handled in the following
1702   ** order:
1703   **
1704   **   (1)  OE_Update
1705   **   (2)  OE_Abort, OE_Fail, OE_Rollback, OE_Ignore
1706   **   (3)  OE_Replace
1707   **
1708   ** OE_Fail and OE_Ignore must happen before any changes are made.
1709   ** OE_Update guarantees that only a single row will change, so it
1710   ** must happen before OE_Replace.  Technically, OE_Abort and OE_Rollback
1711   ** could happen in any order, but they are grouped up front for
1712   ** convenience.
1713   **
1714   ** 2018-08-14: Ticket https://www.sqlite.org/src/info/908f001483982c43
1715   ** The order of constraints used to have OE_Update as (2) and OE_Abort
1716   ** and so forth as (1). But apparently PostgreSQL checks the OE_Update
1717   ** constraint before any others, so it had to be moved.
1718   **
1719   ** Constraint checking code is generated in this order:
1720   **   (A)  The rowid constraint
1721   **   (B)  Unique index constraints that do not have OE_Replace as their
1722   **        default conflict resolution strategy
1723   **   (C)  Unique index that do use OE_Replace by default.
1724   **
1725   ** The ordering of (2) and (3) is accomplished by making sure the linked
1726   ** list of indexes attached to a table puts all OE_Replace indexes last
1727   ** in the list.  See sqlite3CreateIndex() for where that happens.
1728   */
1729 
1730   if( pUpsert ){
1731     if( pUpsert->pUpsertTarget==0 ){
1732       /* An ON CONFLICT DO NOTHING clause, without a constraint-target.
1733       ** Make all unique constraint resolution be OE_Ignore */
1734       assert( pUpsert->pUpsertSet==0 );
1735       overrideError = OE_Ignore;
1736       pUpsert = 0;
1737     }else if( (pUpIdx = pUpsert->pUpsertIdx)!=0 ){
1738       /* If the constraint-target uniqueness check must be run first.
1739       ** Jump to that uniqueness check now */
1740       upsertJump = sqlite3VdbeAddOp0(v, OP_Goto);
1741       VdbeComment((v, "UPSERT constraint goes first"));
1742     }
1743   }
1744 
1745   /* Determine if it is possible that triggers (either explicitly coded
1746   ** triggers or FK resolution actions) might run as a result of deletes
1747   ** that happen when OE_Replace conflict resolution occurs. (Call these
1748   ** "replace triggers".)  If any replace triggers run, we will need to
1749   ** recheck all of the uniqueness constraints after they have all run.
1750   ** But on the recheck, the resolution is OE_Abort instead of OE_Replace.
1751   **
1752   ** If replace triggers are a possibility, then
1753   **
1754   **   (1) Allocate register regTrigCnt and initialize it to zero.
1755   **       That register will count the number of replace triggers that
1756   **       fire.  Constraint recheck only occurs if the number is positive.
1757   **   (2) Initialize pTrigger to the list of all DELETE triggers on pTab.
1758   **   (3) Initialize addrRecheck and lblRecheckOk
1759   **
1760   ** The uniqueness rechecking code will create a series of tests to run
1761   ** in a second pass.  The addrRecheck and lblRecheckOk variables are
1762   ** used to link together these tests which are separated from each other
1763   ** in the generate bytecode.
1764   */
1765   if( (db->flags & (SQLITE_RecTriggers|SQLITE_ForeignKeys))==0 ){
1766     /* There are not DELETE triggers nor FK constraints.  No constraint
1767     ** rechecks are needed. */
1768     pTrigger = 0;
1769     regTrigCnt = 0;
1770   }else{
1771     if( db->flags&SQLITE_RecTriggers ){
1772       pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1773       regTrigCnt = pTrigger!=0 || sqlite3FkRequired(pParse, pTab, 0, 0);
1774     }else{
1775       pTrigger = 0;
1776       regTrigCnt = sqlite3FkRequired(pParse, pTab, 0, 0);
1777     }
1778     if( regTrigCnt ){
1779       /* Replace triggers might exist.  Allocate the counter and
1780       ** initialize it to zero. */
1781       regTrigCnt = ++pParse->nMem;
1782       sqlite3VdbeAddOp2(v, OP_Integer, 0, regTrigCnt);
1783       VdbeComment((v, "trigger count"));
1784       lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
1785       addrRecheck = lblRecheckOk;
1786     }
1787   }
1788 
1789   /* If rowid is changing, make sure the new rowid does not previously
1790   ** exist in the table.
1791   */
1792   if( pkChng && pPk==0 ){
1793     int addrRowidOk = sqlite3VdbeMakeLabel(pParse);
1794 
1795     /* Figure out what action to take in case of a rowid collision */
1796     onError = pTab->keyConf;
1797     if( overrideError!=OE_Default ){
1798       onError = overrideError;
1799     }else if( onError==OE_Default ){
1800       onError = OE_Abort;
1801     }
1802 
1803     /* figure out whether or not upsert applies in this case */
1804     if( pUpsert && pUpsert->pUpsertIdx==0 ){
1805       if( pUpsert->pUpsertSet==0 ){
1806         onError = OE_Ignore;  /* DO NOTHING is the same as INSERT OR IGNORE */
1807       }else{
1808         onError = OE_Update;  /* DO UPDATE */
1809       }
1810     }
1811 
1812     /* If the response to a rowid conflict is REPLACE but the response
1813     ** to some other UNIQUE constraint is FAIL or IGNORE, then we need
1814     ** to defer the running of the rowid conflict checking until after
1815     ** the UNIQUE constraints have run.
1816     */
1817     if( onError==OE_Replace      /* IPK rule is REPLACE */
1818      && onError!=overrideError   /* Rules for other contraints are different */
1819      && pTab->pIndex             /* There exist other constraints */
1820     ){
1821       ipkTop = sqlite3VdbeAddOp0(v, OP_Goto)+1;
1822       VdbeComment((v, "defer IPK REPLACE until last"));
1823     }
1824 
1825     if( isUpdate ){
1826       /* pkChng!=0 does not mean that the rowid has changed, only that
1827       ** it might have changed.  Skip the conflict logic below if the rowid
1828       ** is unchanged. */
1829       sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
1830       sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
1831       VdbeCoverage(v);
1832     }
1833 
1834     /* Check to see if the new rowid already exists in the table.  Skip
1835     ** the following conflict logic if it does not. */
1836     VdbeNoopComment((v, "uniqueness check for ROWID"));
1837     sqlite3VdbeVerifyAbortable(v, onError);
1838     sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);
1839     VdbeCoverage(v);
1840 
1841     switch( onError ){
1842       default: {
1843         onError = OE_Abort;
1844         /* no break */ deliberate_fall_through
1845       }
1846       case OE_Rollback:
1847       case OE_Abort:
1848       case OE_Fail: {
1849         testcase( onError==OE_Rollback );
1850         testcase( onError==OE_Abort );
1851         testcase( onError==OE_Fail );
1852         sqlite3RowidConstraint(pParse, onError, pTab);
1853         break;
1854       }
1855       case OE_Replace: {
1856         /* If there are DELETE triggers on this table and the
1857         ** recursive-triggers flag is set, call GenerateRowDelete() to
1858         ** remove the conflicting row from the table. This will fire
1859         ** the triggers and remove both the table and index b-tree entries.
1860         **
1861         ** Otherwise, if there are no triggers or the recursive-triggers
1862         ** flag is not set, but the table has one or more indexes, call
1863         ** GenerateRowIndexDelete(). This removes the index b-tree entries
1864         ** only. The table b-tree entry will be replaced by the new entry
1865         ** when it is inserted.
1866         **
1867         ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
1868         ** also invoke MultiWrite() to indicate that this VDBE may require
1869         ** statement rollback (if the statement is aborted after the delete
1870         ** takes place). Earlier versions called sqlite3MultiWrite() regardless,
1871         ** but being more selective here allows statements like:
1872         **
1873         **   REPLACE INTO t(rowid) VALUES($newrowid)
1874         **
1875         ** to run without a statement journal if there are no indexes on the
1876         ** table.
1877         */
1878         if( regTrigCnt ){
1879           sqlite3MultiWrite(pParse);
1880           sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
1881                                    regNewData, 1, 0, OE_Replace, 1, -1);
1882           sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
1883           nReplaceTrig++;
1884         }else{
1885 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1886           assert( HasRowid(pTab) );
1887           /* This OP_Delete opcode fires the pre-update-hook only. It does
1888           ** not modify the b-tree. It is more efficient to let the coming
1889           ** OP_Insert replace the existing entry than it is to delete the
1890           ** existing entry and then insert a new one. */
1891           sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
1892           sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
1893 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1894           if( pTab->pIndex ){
1895             sqlite3MultiWrite(pParse);
1896             sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
1897           }
1898         }
1899         seenReplace = 1;
1900         break;
1901       }
1902 #ifndef SQLITE_OMIT_UPSERT
1903       case OE_Update: {
1904         sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, 0, iDataCur);
1905         /* no break */ deliberate_fall_through
1906       }
1907 #endif
1908       case OE_Ignore: {
1909         testcase( onError==OE_Ignore );
1910         sqlite3VdbeGoto(v, ignoreDest);
1911         break;
1912       }
1913     }
1914     sqlite3VdbeResolveLabel(v, addrRowidOk);
1915     if( ipkTop ){
1916       ipkBottom = sqlite3VdbeAddOp0(v, OP_Goto);
1917       sqlite3VdbeJumpHere(v, ipkTop-1);
1918     }
1919   }
1920 
1921   /* Test all UNIQUE constraints by creating entries for each UNIQUE
1922   ** index and making sure that duplicate entries do not already exist.
1923   ** Compute the revised record entries for indices as we go.
1924   **
1925   ** This loop also handles the case of the PRIMARY KEY index for a
1926   ** WITHOUT ROWID table.
1927   */
1928   for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){
1929     int regIdx;          /* Range of registers hold conent for pIdx */
1930     int regR;            /* Range of registers holding conflicting PK */
1931     int iThisCur;        /* Cursor for this UNIQUE index */
1932     int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */
1933     int addrConflictCk;  /* First opcode in the conflict check logic */
1934 
1935     if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
1936     if( pUpIdx==pIdx ){
1937       addrUniqueOk = upsertJump+1;
1938       upsertBypass = sqlite3VdbeGoto(v, 0);
1939       VdbeComment((v, "Skip upsert subroutine"));
1940       sqlite3VdbeJumpHere(v, upsertJump);
1941     }else{
1942       addrUniqueOk = sqlite3VdbeMakeLabel(pParse);
1943     }
1944     if( bAffinityDone==0 && (pUpIdx==0 || pUpIdx==pIdx) ){
1945       sqlite3TableAffinity(v, pTab, regNewData+1);
1946       bAffinityDone = 1;
1947     }
1948     VdbeNoopComment((v, "prep index %s", pIdx->zName));
1949     iThisCur = iIdxCur+ix;
1950 
1951 
1952     /* Skip partial indices for which the WHERE clause is not true */
1953     if( pIdx->pPartIdxWhere ){
1954       sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
1955       pParse->iSelfTab = -(regNewData+1);
1956       sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
1957                             SQLITE_JUMPIFNULL);
1958       pParse->iSelfTab = 0;
1959     }
1960 
1961     /* Create a record for this index entry as it should appear after
1962     ** the insert or update.  Store that record in the aRegIdx[ix] register
1963     */
1964     regIdx = aRegIdx[ix]+1;
1965     for(i=0; i<pIdx->nColumn; i++){
1966       int iField = pIdx->aiColumn[i];
1967       int x;
1968       if( iField==XN_EXPR ){
1969         pParse->iSelfTab = -(regNewData+1);
1970         sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
1971         pParse->iSelfTab = 0;
1972         VdbeComment((v, "%s column %d", pIdx->zName, i));
1973       }else if( iField==XN_ROWID || iField==pTab->iPKey ){
1974         x = regNewData;
1975         sqlite3VdbeAddOp2(v, OP_IntCopy, x, regIdx+i);
1976         VdbeComment((v, "rowid"));
1977       }else{
1978         testcase( sqlite3TableColumnToStorage(pTab, iField)!=iField );
1979         x = sqlite3TableColumnToStorage(pTab, iField) + regNewData + 1;
1980         sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
1981         VdbeComment((v, "%s", pTab->aCol[iField].zName));
1982       }
1983     }
1984     sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
1985     VdbeComment((v, "for %s", pIdx->zName));
1986 #ifdef SQLITE_ENABLE_NULL_TRIM
1987     if( pIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
1988       sqlite3SetMakeRecordP5(v, pIdx->pTable);
1989     }
1990 #endif
1991     sqlite3VdbeReleaseRegisters(pParse, regIdx, pIdx->nColumn, 0, 0);
1992 
1993     /* In an UPDATE operation, if this index is the PRIMARY KEY index
1994     ** of a WITHOUT ROWID table and there has been no change the
1995     ** primary key, then no collision is possible.  The collision detection
1996     ** logic below can all be skipped. */
1997     if( isUpdate && pPk==pIdx && pkChng==0 ){
1998       sqlite3VdbeResolveLabel(v, addrUniqueOk);
1999       continue;
2000     }
2001 
2002     /* Find out what action to take in case there is a uniqueness conflict */
2003     onError = pIdx->onError;
2004     if( onError==OE_None ){
2005       sqlite3VdbeResolveLabel(v, addrUniqueOk);
2006       continue;  /* pIdx is not a UNIQUE index */
2007     }
2008     if( overrideError!=OE_Default ){
2009       onError = overrideError;
2010     }else if( onError==OE_Default ){
2011       onError = OE_Abort;
2012     }
2013 
2014     /* Figure out if the upsert clause applies to this index */
2015     if( pUpIdx==pIdx ){
2016       if( pUpsert->pUpsertSet==0 ){
2017         onError = OE_Ignore;  /* DO NOTHING is the same as INSERT OR IGNORE */
2018       }else{
2019         onError = OE_Update;  /* DO UPDATE */
2020       }
2021     }
2022 
2023     /* Collision detection may be omitted if all of the following are true:
2024     **   (1) The conflict resolution algorithm is REPLACE
2025     **   (2) The table is a WITHOUT ROWID table
2026     **   (3) There are no secondary indexes on the table
2027     **   (4) No delete triggers need to be fired if there is a conflict
2028     **   (5) No FK constraint counters need to be updated if a conflict occurs.
2029     **
2030     ** This is not possible for ENABLE_PREUPDATE_HOOK builds, as the row
2031     ** must be explicitly deleted in order to ensure any pre-update hook
2032     ** is invoked.  */
2033 #ifndef SQLITE_ENABLE_PREUPDATE_HOOK
2034     if( (ix==0 && pIdx->pNext==0)                   /* Condition 3 */
2035      && pPk==pIdx                                   /* Condition 2 */
2036      && onError==OE_Replace                         /* Condition 1 */
2037      && ( 0==(db->flags&SQLITE_RecTriggers) ||      /* Condition 4 */
2038           0==sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0))
2039      && ( 0==(db->flags&SQLITE_ForeignKeys) ||      /* Condition 5 */
2040          (0==pTab->pFKey && 0==sqlite3FkReferences(pTab)))
2041     ){
2042       sqlite3VdbeResolveLabel(v, addrUniqueOk);
2043       continue;
2044     }
2045 #endif /* ifndef SQLITE_ENABLE_PREUPDATE_HOOK */
2046 
2047     /* Check to see if the new index entry will be unique */
2048     sqlite3VdbeVerifyAbortable(v, onError);
2049     addrConflictCk =
2050       sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
2051                            regIdx, pIdx->nKeyCol); VdbeCoverage(v);
2052 
2053     /* Generate code to handle collisions */
2054     regR = (pIdx==pPk) ? regIdx : sqlite3GetTempRange(pParse, nPkField);
2055     if( isUpdate || onError==OE_Replace ){
2056       if( HasRowid(pTab) ){
2057         sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
2058         /* Conflict only if the rowid of the existing index entry
2059         ** is different from old-rowid */
2060         if( isUpdate ){
2061           sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);
2062           sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
2063           VdbeCoverage(v);
2064         }
2065       }else{
2066         int x;
2067         /* Extract the PRIMARY KEY from the end of the index entry and
2068         ** store it in registers regR..regR+nPk-1 */
2069         if( pIdx!=pPk ){
2070           for(i=0; i<pPk->nKeyCol; i++){
2071             assert( pPk->aiColumn[i]>=0 );
2072             x = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
2073             sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
2074             VdbeComment((v, "%s.%s", pTab->zName,
2075                          pTab->aCol[pPk->aiColumn[i]].zName));
2076           }
2077         }
2078         if( isUpdate ){
2079           /* If currently processing the PRIMARY KEY of a WITHOUT ROWID
2080           ** table, only conflict if the new PRIMARY KEY values are actually
2081           ** different from the old.
2082           **
2083           ** For a UNIQUE index, only conflict if the PRIMARY KEY values
2084           ** of the matched index row are different from the original PRIMARY
2085           ** KEY values of this row before the update.  */
2086           int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
2087           int op = OP_Ne;
2088           int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
2089 
2090           for(i=0; i<pPk->nKeyCol; i++){
2091             char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
2092             x = pPk->aiColumn[i];
2093             assert( x>=0 );
2094             if( i==(pPk->nKeyCol-1) ){
2095               addrJump = addrUniqueOk;
2096               op = OP_Eq;
2097             }
2098             x = sqlite3TableColumnToStorage(pTab, x);
2099             sqlite3VdbeAddOp4(v, op,
2100                 regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
2101             );
2102             sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
2103             VdbeCoverageIf(v, op==OP_Eq);
2104             VdbeCoverageIf(v, op==OP_Ne);
2105           }
2106         }
2107       }
2108     }
2109 
2110     /* Generate code that executes if the new index entry is not unique */
2111     assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
2112         || onError==OE_Ignore || onError==OE_Replace || onError==OE_Update );
2113     switch( onError ){
2114       case OE_Rollback:
2115       case OE_Abort:
2116       case OE_Fail: {
2117         testcase( onError==OE_Rollback );
2118         testcase( onError==OE_Abort );
2119         testcase( onError==OE_Fail );
2120         sqlite3UniqueConstraint(pParse, onError, pIdx);
2121         break;
2122       }
2123 #ifndef SQLITE_OMIT_UPSERT
2124       case OE_Update: {
2125         sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, pIdx, iIdxCur+ix);
2126         /* no break */ deliberate_fall_through
2127       }
2128 #endif
2129       case OE_Ignore: {
2130         testcase( onError==OE_Ignore );
2131         sqlite3VdbeGoto(v, ignoreDest);
2132         break;
2133       }
2134       default: {
2135         int nConflictCk;   /* Number of opcodes in conflict check logic */
2136 
2137         assert( onError==OE_Replace );
2138         nConflictCk = sqlite3VdbeCurrentAddr(v) - addrConflictCk;
2139         assert( nConflictCk>0 );
2140         testcase( nConflictCk>1 );
2141         if( regTrigCnt ){
2142           sqlite3MultiWrite(pParse);
2143           nReplaceTrig++;
2144         }
2145         if( pTrigger && isUpdate ){
2146           sqlite3VdbeAddOp1(v, OP_CursorLock, iDataCur);
2147         }
2148         sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
2149             regR, nPkField, 0, OE_Replace,
2150             (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
2151         if( pTrigger && isUpdate ){
2152           sqlite3VdbeAddOp1(v, OP_CursorUnlock, iDataCur);
2153         }
2154         if( regTrigCnt ){
2155           int addrBypass;  /* Jump destination to bypass recheck logic */
2156 
2157           sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
2158           addrBypass = sqlite3VdbeAddOp0(v, OP_Goto);  /* Bypass recheck */
2159           VdbeComment((v, "bypass recheck"));
2160 
2161           /* Here we insert code that will be invoked after all constraint
2162           ** checks have run, if and only if one or more replace triggers
2163           ** fired. */
2164           sqlite3VdbeResolveLabel(v, lblRecheckOk);
2165           lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
2166           if( pIdx->pPartIdxWhere ){
2167             /* Bypass the recheck if this partial index is not defined
2168             ** for the current row */
2169             sqlite3VdbeAddOp2(v, OP_IsNull, regIdx-1, lblRecheckOk);
2170             VdbeCoverage(v);
2171           }
2172           /* Copy the constraint check code from above, except change
2173           ** the constraint-ok jump destination to be the address of
2174           ** the next retest block */
2175           while( nConflictCk>0 ){
2176             VdbeOp x;    /* Conflict check opcode to copy */
2177             /* The sqlite3VdbeAddOp4() call might reallocate the opcode array.
2178             ** Hence, make a complete copy of the opcode, rather than using
2179             ** a pointer to the opcode. */
2180             x = *sqlite3VdbeGetOp(v, addrConflictCk);
2181             if( x.opcode!=OP_IdxRowid ){
2182               int p2;      /* New P2 value for copied conflict check opcode */
2183               const char *zP4;
2184               if( sqlite3OpcodeProperty[x.opcode]&OPFLG_JUMP ){
2185                 p2 = lblRecheckOk;
2186               }else{
2187                 p2 = x.p2;
2188               }
2189               zP4 = x.p4type==P4_INT32 ? SQLITE_INT_TO_PTR(x.p4.i) : x.p4.z;
2190               sqlite3VdbeAddOp4(v, x.opcode, x.p1, p2, x.p3, zP4, x.p4type);
2191               sqlite3VdbeChangeP5(v, x.p5);
2192               VdbeCoverageIf(v, p2!=x.p2);
2193             }
2194             nConflictCk--;
2195             addrConflictCk++;
2196           }
2197           /* If the retest fails, issue an abort */
2198           sqlite3UniqueConstraint(pParse, OE_Abort, pIdx);
2199 
2200           sqlite3VdbeJumpHere(v, addrBypass); /* Terminate the recheck bypass */
2201         }
2202         seenReplace = 1;
2203         break;
2204       }
2205     }
2206     if( pUpIdx==pIdx ){
2207       sqlite3VdbeGoto(v, upsertJump+1);
2208       sqlite3VdbeJumpHere(v, upsertBypass);
2209     }else{
2210       sqlite3VdbeResolveLabel(v, addrUniqueOk);
2211     }
2212     if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);
2213   }
2214 
2215   /* If the IPK constraint is a REPLACE, run it last */
2216   if( ipkTop ){
2217     sqlite3VdbeGoto(v, ipkTop);
2218     VdbeComment((v, "Do IPK REPLACE"));
2219     sqlite3VdbeJumpHere(v, ipkBottom);
2220   }
2221 
2222   /* Recheck all uniqueness constraints after replace triggers have run */
2223   testcase( regTrigCnt!=0 && nReplaceTrig==0 );
2224   assert( regTrigCnt!=0 || nReplaceTrig==0 );
2225   if( nReplaceTrig ){
2226     sqlite3VdbeAddOp2(v, OP_IfNot, regTrigCnt, lblRecheckOk);VdbeCoverage(v);
2227     if( !pPk ){
2228       if( isUpdate ){
2229         sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRecheck, regOldData);
2230         sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
2231         VdbeCoverage(v);
2232       }
2233       sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRecheck, regNewData);
2234       VdbeCoverage(v);
2235       sqlite3RowidConstraint(pParse, OE_Abort, pTab);
2236     }else{
2237       sqlite3VdbeGoto(v, addrRecheck);
2238     }
2239     sqlite3VdbeResolveLabel(v, lblRecheckOk);
2240   }
2241 
2242   /* Generate the table record */
2243   if( HasRowid(pTab) ){
2244     int regRec = aRegIdx[ix];
2245     sqlite3VdbeAddOp3(v, OP_MakeRecord, regNewData+1, pTab->nNVCol, regRec);
2246     sqlite3SetMakeRecordP5(v, pTab);
2247     if( !bAffinityDone ){
2248       sqlite3TableAffinity(v, pTab, 0);
2249     }
2250   }
2251 
2252   *pbMayReplace = seenReplace;
2253   VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));
2254 }
2255 
2256 #ifdef SQLITE_ENABLE_NULL_TRIM
2257 /*
2258 ** Change the P5 operand on the last opcode (which should be an OP_MakeRecord)
2259 ** to be the number of columns in table pTab that must not be NULL-trimmed.
2260 **
2261 ** Or if no columns of pTab may be NULL-trimmed, leave P5 at zero.
2262 */
sqlite3SetMakeRecordP5(Vdbe * v,Table * pTab)2263 void sqlite3SetMakeRecordP5(Vdbe *v, Table *pTab){
2264   u16 i;
2265 
2266   /* Records with omitted columns are only allowed for schema format
2267   ** version 2 and later (SQLite version 3.1.4, 2005-02-20). */
2268   if( pTab->pSchema->file_format<2 ) return;
2269 
2270   for(i=pTab->nCol-1; i>0; i--){
2271     if( pTab->aCol[i].pDflt!=0 ) break;
2272     if( pTab->aCol[i].colFlags & COLFLAG_PRIMKEY ) break;
2273   }
2274   sqlite3VdbeChangeP5(v, i+1);
2275 }
2276 #endif
2277 
2278 /*
2279 ** This routine generates code to finish the INSERT or UPDATE operation
2280 ** that was started by a prior call to sqlite3GenerateConstraintChecks.
2281 ** A consecutive range of registers starting at regNewData contains the
2282 ** rowid and the content to be inserted.
2283 **
2284 ** The arguments to this routine should be the same as the first six
2285 ** arguments to sqlite3GenerateConstraintChecks.
2286 */
sqlite3CompleteInsertion(Parse * pParse,Table * pTab,int iDataCur,int iIdxCur,int regNewData,int * aRegIdx,int update_flags,int appendBias,int useSeekResult)2287 void sqlite3CompleteInsertion(
2288   Parse *pParse,      /* The parser context */
2289   Table *pTab,        /* the table into which we are inserting */
2290   int iDataCur,       /* Cursor of the canonical data source */
2291   int iIdxCur,        /* First index cursor */
2292   int regNewData,     /* Range of content */
2293   int *aRegIdx,       /* Register used by each index.  0 for unused indices */
2294   int update_flags,   /* True for UPDATE, False for INSERT */
2295   int appendBias,     /* True if this is likely to be an append */
2296   int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
2297 ){
2298   Vdbe *v;            /* Prepared statements under construction */
2299   Index *pIdx;        /* An index being inserted or updated */
2300   u8 pik_flags;       /* flag values passed to the btree insert */
2301   int i;              /* Loop counter */
2302 
2303   assert( update_flags==0
2304        || update_flags==OPFLAG_ISUPDATE
2305        || update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)
2306   );
2307 
2308   v = pParse->pVdbe;
2309   assert( v!=0 );
2310   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
2311   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
2312     /* All REPLACE indexes are at the end of the list */
2313     assert( pIdx->onError!=OE_Replace
2314          || pIdx->pNext==0
2315          || pIdx->pNext->onError==OE_Replace );
2316     if( aRegIdx[i]==0 ) continue;
2317     if( pIdx->pPartIdxWhere ){
2318       sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
2319       VdbeCoverage(v);
2320     }
2321     pik_flags = (useSeekResult ? OPFLAG_USESEEKRESULT : 0);
2322     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
2323       assert( pParse->nested==0 );
2324       pik_flags |= OPFLAG_NCHANGE;
2325       pik_flags |= (update_flags & OPFLAG_SAVEPOSITION);
2326 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2327       if( update_flags==0 ){
2328         int r = sqlite3GetTempReg(pParse);
2329         sqlite3VdbeAddOp2(v, OP_Integer, 0, r);
2330         sqlite3VdbeAddOp4(v, OP_Insert,
2331             iIdxCur+i, aRegIdx[i], r, (char*)pTab, P4_TABLE
2332         );
2333         sqlite3VdbeChangeP5(v, OPFLAG_ISNOOP);
2334         sqlite3ReleaseTempReg(pParse, r);
2335       }
2336 #endif
2337     }
2338     sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i],
2339                          aRegIdx[i]+1,
2340                          pIdx->uniqNotNull ? pIdx->nKeyCol: pIdx->nColumn);
2341     sqlite3VdbeChangeP5(v, pik_flags);
2342   }
2343   if( !HasRowid(pTab) ) return;
2344   if( pParse->nested ){
2345     pik_flags = 0;
2346   }else{
2347     pik_flags = OPFLAG_NCHANGE;
2348     pik_flags |= (update_flags?update_flags:OPFLAG_LASTROWID);
2349   }
2350   if( appendBias ){
2351     pik_flags |= OPFLAG_APPEND;
2352   }
2353   if( useSeekResult ){
2354     pik_flags |= OPFLAG_USESEEKRESULT;
2355   }
2356   sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, aRegIdx[i], regNewData);
2357   if( !pParse->nested ){
2358     sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
2359   }
2360   sqlite3VdbeChangeP5(v, pik_flags);
2361 }
2362 
2363 /*
2364 ** Allocate cursors for the pTab table and all its indices and generate
2365 ** code to open and initialized those cursors.
2366 **
2367 ** The cursor for the object that contains the complete data (normally
2368 ** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
2369 ** ROWID table) is returned in *piDataCur.  The first index cursor is
2370 ** returned in *piIdxCur.  The number of indices is returned.
2371 **
2372 ** Use iBase as the first cursor (either the *piDataCur for rowid tables
2373 ** or the first index for WITHOUT ROWID tables) if it is non-negative.
2374 ** If iBase is negative, then allocate the next available cursor.
2375 **
2376 ** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
2377 ** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
2378 ** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
2379 ** pTab->pIndex list.
2380 **
2381 ** If pTab is a virtual table, then this routine is a no-op and the
2382 ** *piDataCur and *piIdxCur values are left uninitialized.
2383 */
sqlite3OpenTableAndIndices(Parse * pParse,Table * pTab,int op,u8 p5,int iBase,u8 * aToOpen,int * piDataCur,int * piIdxCur)2384 int sqlite3OpenTableAndIndices(
2385   Parse *pParse,   /* Parsing context */
2386   Table *pTab,     /* Table to be opened */
2387   int op,          /* OP_OpenRead or OP_OpenWrite */
2388   u8 p5,           /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */
2389   int iBase,       /* Use this for the table cursor, if there is one */
2390   u8 *aToOpen,     /* If not NULL: boolean for each table and index */
2391   int *piDataCur,  /* Write the database source cursor number here */
2392   int *piIdxCur    /* Write the first index cursor number here */
2393 ){
2394   int i;
2395   int iDb;
2396   int iDataCur;
2397   Index *pIdx;
2398   Vdbe *v;
2399 
2400   assert( op==OP_OpenRead || op==OP_OpenWrite );
2401   assert( op==OP_OpenWrite || p5==0 );
2402   if( IsVirtual(pTab) ){
2403     /* This routine is a no-op for virtual tables. Leave the output
2404     ** variables *piDataCur and *piIdxCur uninitialized so that valgrind
2405     ** can detect if they are used by mistake in the caller. */
2406     return 0;
2407   }
2408   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
2409   v = pParse->pVdbe;
2410   assert( v!=0 );
2411   if( iBase<0 ) iBase = pParse->nTab;
2412   iDataCur = iBase++;
2413   if( piDataCur ) *piDataCur = iDataCur;
2414   if( HasRowid(pTab) && (aToOpen==0 || aToOpen[0]) ){
2415     sqlite3OpenTable(pParse, iDataCur, iDb, pTab, op);
2416   }else{
2417     sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
2418   }
2419   if( piIdxCur ) *piIdxCur = iBase;
2420   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
2421     int iIdxCur = iBase++;
2422     assert( pIdx->pSchema==pTab->pSchema );
2423     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
2424       if( piDataCur ) *piDataCur = iIdxCur;
2425       p5 = 0;
2426     }
2427     if( aToOpen==0 || aToOpen[i+1] ){
2428       sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
2429       sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
2430       sqlite3VdbeChangeP5(v, p5);
2431       VdbeComment((v, "%s", pIdx->zName));
2432     }
2433   }
2434   if( iBase>pParse->nTab ) pParse->nTab = iBase;
2435   return i;
2436 }
2437 
2438 
2439 #ifdef SQLITE_TEST
2440 /*
2441 ** The following global variable is incremented whenever the
2442 ** transfer optimization is used.  This is used for testing
2443 ** purposes only - to make sure the transfer optimization really
2444 ** is happening when it is supposed to.
2445 */
2446 int sqlite3_xferopt_count;
2447 #endif /* SQLITE_TEST */
2448 
2449 
2450 #ifndef SQLITE_OMIT_XFER_OPT
2451 /*
2452 ** Check to see if index pSrc is compatible as a source of data
2453 ** for index pDest in an insert transfer optimization.  The rules
2454 ** for a compatible index:
2455 **
2456 **    *   The index is over the same set of columns
2457 **    *   The same DESC and ASC markings occurs on all columns
2458 **    *   The same onError processing (OE_Abort, OE_Ignore, etc)
2459 **    *   The same collating sequence on each column
2460 **    *   The index has the exact same WHERE clause
2461 */
xferCompatibleIndex(Index * pDest,Index * pSrc)2462 static int xferCompatibleIndex(Index *pDest, Index *pSrc){
2463   int i;
2464   assert( pDest && pSrc );
2465   assert( pDest->pTable!=pSrc->pTable );
2466   if( pDest->nKeyCol!=pSrc->nKeyCol || pDest->nColumn!=pSrc->nColumn ){
2467     return 0;   /* Different number of columns */
2468   }
2469   if( pDest->onError!=pSrc->onError ){
2470     return 0;   /* Different conflict resolution strategies */
2471   }
2472   for(i=0; i<pSrc->nKeyCol; i++){
2473     if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
2474       return 0;   /* Different columns indexed */
2475     }
2476     if( pSrc->aiColumn[i]==XN_EXPR ){
2477       assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
2478       if( sqlite3ExprCompare(0, pSrc->aColExpr->a[i].pExpr,
2479                              pDest->aColExpr->a[i].pExpr, -1)!=0 ){
2480         return 0;   /* Different expressions in the index */
2481       }
2482     }
2483     if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
2484       return 0;   /* Different sort orders */
2485     }
2486     if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){
2487       return 0;   /* Different collating sequences */
2488     }
2489   }
2490   if( sqlite3ExprCompare(0, pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
2491     return 0;     /* Different WHERE clauses */
2492   }
2493 
2494   /* If no test above fails then the indices must be compatible */
2495   return 1;
2496 }
2497 
2498 /*
2499 ** Attempt the transfer optimization on INSERTs of the form
2500 **
2501 **     INSERT INTO tab1 SELECT * FROM tab2;
2502 **
2503 ** The xfer optimization transfers raw records from tab2 over to tab1.
2504 ** Columns are not decoded and reassembled, which greatly improves
2505 ** performance.  Raw index records are transferred in the same way.
2506 **
2507 ** The xfer optimization is only attempted if tab1 and tab2 are compatible.
2508 ** There are lots of rules for determining compatibility - see comments
2509 ** embedded in the code for details.
2510 **
2511 ** This routine returns TRUE if the optimization is guaranteed to be used.
2512 ** Sometimes the xfer optimization will only work if the destination table
2513 ** is empty - a factor that can only be determined at run-time.  In that
2514 ** case, this routine generates code for the xfer optimization but also
2515 ** does a test to see if the destination table is empty and jumps over the
2516 ** xfer optimization code if the test fails.  In that case, this routine
2517 ** returns FALSE so that the caller will know to go ahead and generate
2518 ** an unoptimized transfer.  This routine also returns FALSE if there
2519 ** is no chance that the xfer optimization can be applied.
2520 **
2521 ** This optimization is particularly useful at making VACUUM run faster.
2522 */
xferOptimization(Parse * pParse,Table * pDest,Select * pSelect,int onError,int iDbDest)2523 static int xferOptimization(
2524   Parse *pParse,        /* Parser context */
2525   Table *pDest,         /* The table we are inserting into */
2526   Select *pSelect,      /* A SELECT statement to use as the data source */
2527   int onError,          /* How to handle constraint errors */
2528   int iDbDest           /* The database of pDest */
2529 ){
2530   sqlite3 *db = pParse->db;
2531   ExprList *pEList;                /* The result set of the SELECT */
2532   Table *pSrc;                     /* The table in the FROM clause of SELECT */
2533   Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
2534   struct SrcList_item *pItem;      /* An element of pSelect->pSrc */
2535   int i;                           /* Loop counter */
2536   int iDbSrc;                      /* The database of pSrc */
2537   int iSrc, iDest;                 /* Cursors from source and destination */
2538   int addr1, addr2;                /* Loop addresses */
2539   int emptyDestTest = 0;           /* Address of test for empty pDest */
2540   int emptySrcTest = 0;            /* Address of test for empty pSrc */
2541   Vdbe *v;                         /* The VDBE we are building */
2542   int regAutoinc;                  /* Memory register used by AUTOINC */
2543   int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
2544   int regData, regRowid;           /* Registers holding data and rowid */
2545 
2546   if( pSelect==0 ){
2547     return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
2548   }
2549   if( pParse->pWith || pSelect->pWith ){
2550     /* Do not attempt to process this query if there are an WITH clauses
2551     ** attached to it. Proceeding may generate a false "no such table: xxx"
2552     ** error if pSelect reads from a CTE named "xxx".  */
2553     return 0;
2554   }
2555   if( sqlite3TriggerList(pParse, pDest) ){
2556     return 0;   /* tab1 must not have triggers */
2557   }
2558 #ifndef SQLITE_OMIT_VIRTUALTABLE
2559   if( IsVirtual(pDest) ){
2560     return 0;   /* tab1 must not be a virtual table */
2561   }
2562 #endif
2563   if( onError==OE_Default ){
2564     if( pDest->iPKey>=0 ) onError = pDest->keyConf;
2565     if( onError==OE_Default ) onError = OE_Abort;
2566   }
2567   assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
2568   if( pSelect->pSrc->nSrc!=1 ){
2569     return 0;   /* FROM clause must have exactly one term */
2570   }
2571   if( pSelect->pSrc->a[0].pSelect ){
2572     return 0;   /* FROM clause cannot contain a subquery */
2573   }
2574   if( pSelect->pWhere ){
2575     return 0;   /* SELECT may not have a WHERE clause */
2576   }
2577   if( pSelect->pOrderBy ){
2578     return 0;   /* SELECT may not have an ORDER BY clause */
2579   }
2580   /* Do not need to test for a HAVING clause.  If HAVING is present but
2581   ** there is no ORDER BY, we will get an error. */
2582   if( pSelect->pGroupBy ){
2583     return 0;   /* SELECT may not have a GROUP BY clause */
2584   }
2585   if( pSelect->pLimit ){
2586     return 0;   /* SELECT may not have a LIMIT clause */
2587   }
2588   if( pSelect->pPrior ){
2589     return 0;   /* SELECT may not be a compound query */
2590   }
2591   if( pSelect->selFlags & SF_Distinct ){
2592     return 0;   /* SELECT may not be DISTINCT */
2593   }
2594   pEList = pSelect->pEList;
2595   assert( pEList!=0 );
2596   if( pEList->nExpr!=1 ){
2597     return 0;   /* The result set must have exactly one column */
2598   }
2599   assert( pEList->a[0].pExpr );
2600   if( pEList->a[0].pExpr->op!=TK_ASTERISK ){
2601     return 0;   /* The result set must be the special operator "*" */
2602   }
2603 
2604   /* At this point we have established that the statement is of the
2605   ** correct syntactic form to participate in this optimization.  Now
2606   ** we have to check the semantics.
2607   */
2608   pItem = pSelect->pSrc->a;
2609   pSrc = sqlite3LocateTableItem(pParse, 0, pItem);
2610   if( pSrc==0 ){
2611     return 0;   /* FROM clause does not contain a real table */
2612   }
2613   if( pSrc->tnum==pDest->tnum && pSrc->pSchema==pDest->pSchema ){
2614     testcase( pSrc!=pDest ); /* Possible due to bad sqlite_schema.rootpage */
2615     return 0;   /* tab1 and tab2 may not be the same table */
2616   }
2617   if( HasRowid(pDest)!=HasRowid(pSrc) ){
2618     return 0;   /* source and destination must both be WITHOUT ROWID or not */
2619   }
2620 #ifndef SQLITE_OMIT_VIRTUALTABLE
2621   if( IsVirtual(pSrc) ){
2622     return 0;   /* tab2 must not be a virtual table */
2623   }
2624 #endif
2625   if( pSrc->pSelect ){
2626     return 0;   /* tab2 may not be a view */
2627   }
2628   if( pDest->nCol!=pSrc->nCol ){
2629     return 0;   /* Number of columns must be the same in tab1 and tab2 */
2630   }
2631   if( pDest->iPKey!=pSrc->iPKey ){
2632     return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
2633   }
2634   for(i=0; i<pDest->nCol; i++){
2635     Column *pDestCol = &pDest->aCol[i];
2636     Column *pSrcCol = &pSrc->aCol[i];
2637 #ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
2638     if( (db->mDbFlags & DBFLAG_Vacuum)==0
2639      && (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN
2640     ){
2641       return 0;    /* Neither table may have __hidden__ columns */
2642     }
2643 #endif
2644 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
2645     /* Even if tables t1 and t2 have identical schemas, if they contain
2646     ** generated columns, then this statement is semantically incorrect:
2647     **
2648     **     INSERT INTO t2 SELECT * FROM t1;
2649     **
2650     ** The reason is that generated column values are returned by the
2651     ** the SELECT statement on the right but the INSERT statement on the
2652     ** left wants them to be omitted.
2653     **
2654     ** Nevertheless, this is a useful notational shorthand to tell SQLite
2655     ** to do a bulk transfer all of the content from t1 over to t2.
2656     **
2657     ** We could, in theory, disable this (except for internal use by the
2658     ** VACUUM command where it is actually needed).  But why do that?  It
2659     ** seems harmless enough, and provides a useful service.
2660     */
2661     if( (pDestCol->colFlags & COLFLAG_GENERATED) !=
2662         (pSrcCol->colFlags & COLFLAG_GENERATED) ){
2663       return 0;    /* Both columns have the same generated-column type */
2664     }
2665     /* But the transfer is only allowed if both the source and destination
2666     ** tables have the exact same expressions for generated columns.
2667     ** This requirement could be relaxed for VIRTUAL columns, I suppose.
2668     */
2669     if( (pDestCol->colFlags & COLFLAG_GENERATED)!=0 ){
2670       if( sqlite3ExprCompare(0, pSrcCol->pDflt, pDestCol->pDflt, -1)!=0 ){
2671         testcase( pDestCol->colFlags & COLFLAG_VIRTUAL );
2672         testcase( pDestCol->colFlags & COLFLAG_STORED );
2673         return 0;  /* Different generator expressions */
2674       }
2675     }
2676 #endif
2677     if( pDestCol->affinity!=pSrcCol->affinity ){
2678       return 0;    /* Affinity must be the same on all columns */
2679     }
2680     if( sqlite3_stricmp(pDestCol->zColl, pSrcCol->zColl)!=0 ){
2681       return 0;    /* Collating sequence must be the same on all columns */
2682     }
2683     if( pDestCol->notNull && !pSrcCol->notNull ){
2684       return 0;    /* tab2 must be NOT NULL if tab1 is */
2685     }
2686     /* Default values for second and subsequent columns need to match. */
2687     if( (pDestCol->colFlags & COLFLAG_GENERATED)==0 && i>0 ){
2688       assert( pDestCol->pDflt==0 || pDestCol->pDflt->op==TK_SPAN );
2689       assert( pSrcCol->pDflt==0 || pSrcCol->pDflt->op==TK_SPAN );
2690       if( (pDestCol->pDflt==0)!=(pSrcCol->pDflt==0)
2691        || (pDestCol->pDflt && strcmp(pDestCol->pDflt->u.zToken,
2692                                        pSrcCol->pDflt->u.zToken)!=0)
2693       ){
2694         return 0;    /* Default values must be the same for all columns */
2695       }
2696     }
2697   }
2698   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
2699     if( IsUniqueIndex(pDestIdx) ){
2700       destHasUniqueIdx = 1;
2701     }
2702     for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
2703       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
2704     }
2705     if( pSrcIdx==0 ){
2706       return 0;    /* pDestIdx has no corresponding index in pSrc */
2707     }
2708     if( pSrcIdx->tnum==pDestIdx->tnum && pSrc->pSchema==pDest->pSchema
2709          && sqlite3FaultSim(411)==SQLITE_OK ){
2710       /* The sqlite3FaultSim() call allows this corruption test to be
2711       ** bypassed during testing, in order to exercise other corruption tests
2712       ** further downstream. */
2713       return 0;   /* Corrupt schema - two indexes on the same btree */
2714     }
2715   }
2716 #ifndef SQLITE_OMIT_CHECK
2717   if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){
2718     return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
2719   }
2720 #endif
2721 #ifndef SQLITE_OMIT_FOREIGN_KEY
2722   /* Disallow the transfer optimization if the destination table constains
2723   ** any foreign key constraints.  This is more restrictive than necessary.
2724   ** But the main beneficiary of the transfer optimization is the VACUUM
2725   ** command, and the VACUUM command disables foreign key constraints.  So
2726   ** the extra complication to make this rule less restrictive is probably
2727   ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
2728   */
2729   if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
2730     return 0;
2731   }
2732 #endif
2733   if( (db->flags & SQLITE_CountRows)!=0 ){
2734     return 0;  /* xfer opt does not play well with PRAGMA count_changes */
2735   }
2736 
2737   /* If we get this far, it means that the xfer optimization is at
2738   ** least a possibility, though it might only work if the destination
2739   ** table (tab1) is initially empty.
2740   */
2741 #ifdef SQLITE_TEST
2742   sqlite3_xferopt_count++;
2743 #endif
2744   iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);
2745   v = sqlite3GetVdbe(pParse);
2746   sqlite3CodeVerifySchema(pParse, iDbSrc);
2747   iSrc = pParse->nTab++;
2748   iDest = pParse->nTab++;
2749   regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
2750   regData = sqlite3GetTempReg(pParse);
2751   regRowid = sqlite3GetTempReg(pParse);
2752   sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
2753   assert( HasRowid(pDest) || destHasUniqueIdx );
2754   if( (db->mDbFlags & DBFLAG_Vacuum)==0 && (
2755       (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
2756    || destHasUniqueIdx                              /* (2) */
2757    || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */
2758   )){
2759     /* In some circumstances, we are able to run the xfer optimization
2760     ** only if the destination table is initially empty. Unless the
2761     ** DBFLAG_Vacuum flag is set, this block generates code to make
2762     ** that determination. If DBFLAG_Vacuum is set, then the destination
2763     ** table is always empty.
2764     **
2765     ** Conditions under which the destination must be empty:
2766     **
2767     ** (1) There is no INTEGER PRIMARY KEY but there are indices.
2768     **     (If the destination is not initially empty, the rowid fields
2769     **     of index entries might need to change.)
2770     **
2771     ** (2) The destination has a unique index.  (The xfer optimization
2772     **     is unable to test uniqueness.)
2773     **
2774     ** (3) onError is something other than OE_Abort and OE_Rollback.
2775     */
2776     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);
2777     emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);
2778     sqlite3VdbeJumpHere(v, addr1);
2779   }
2780   if( HasRowid(pSrc) ){
2781     u8 insFlags;
2782     sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
2783     emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
2784     if( pDest->iPKey>=0 ){
2785       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
2786       sqlite3VdbeVerifyAbortable(v, onError);
2787       addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
2788       VdbeCoverage(v);
2789       sqlite3RowidConstraint(pParse, onError, pDest);
2790       sqlite3VdbeJumpHere(v, addr2);
2791       autoIncStep(pParse, regAutoinc, regRowid);
2792     }else if( pDest->pIndex==0 && !(db->mDbFlags & DBFLAG_VacuumInto) ){
2793       addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
2794     }else{
2795       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
2796       assert( (pDest->tabFlags & TF_Autoincrement)==0 );
2797     }
2798     if( db->mDbFlags & DBFLAG_Vacuum ){
2799       sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
2800       insFlags = OPFLAG_APPEND|OPFLAG_USESEEKRESULT;
2801     }else{
2802       insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;
2803     }
2804     sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
2805     sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
2806                       (char*)pDest, P4_TABLE);
2807     sqlite3VdbeChangeP5(v, insFlags);
2808     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
2809     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
2810     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
2811   }else{
2812     sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);
2813     sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
2814   }
2815   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
2816     u8 idxInsFlags = 0;
2817     for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
2818       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
2819     }
2820     assert( pSrcIdx );
2821     sqlite3VdbeAddOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc);
2822     sqlite3VdbeSetP4KeyInfo(pParse, pSrcIdx);
2823     VdbeComment((v, "%s", pSrcIdx->zName));
2824     sqlite3VdbeAddOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest);
2825     sqlite3VdbeSetP4KeyInfo(pParse, pDestIdx);
2826     sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
2827     VdbeComment((v, "%s", pDestIdx->zName));
2828     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
2829     if( db->mDbFlags & DBFLAG_Vacuum ){
2830       /* This INSERT command is part of a VACUUM operation, which guarantees
2831       ** that the destination table is empty. If all indexed columns use
2832       ** collation sequence BINARY, then it can also be assumed that the
2833       ** index will be populated by inserting keys in strictly sorted
2834       ** order. In this case, instead of seeking within the b-tree as part
2835       ** of every OP_IdxInsert opcode, an OP_SeekEnd is added before the
2836       ** OP_IdxInsert to seek to the point within the b-tree where each key
2837       ** should be inserted. This is faster.
2838       **
2839       ** If any of the indexed columns use a collation sequence other than
2840       ** BINARY, this optimization is disabled. This is because the user
2841       ** might change the definition of a collation sequence and then run
2842       ** a VACUUM command. In that case keys may not be written in strictly
2843       ** sorted order.  */
2844       for(i=0; i<pSrcIdx->nColumn; i++){
2845         const char *zColl = pSrcIdx->azColl[i];
2846         if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
2847       }
2848       if( i==pSrcIdx->nColumn ){
2849         idxInsFlags = OPFLAG_USESEEKRESULT;
2850         sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
2851       }
2852     }else if( !HasRowid(pSrc) && pDestIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
2853       idxInsFlags |= OPFLAG_NCHANGE;
2854     }
2855     sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
2856     sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
2857     sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);
2858     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
2859     sqlite3VdbeJumpHere(v, addr1);
2860     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
2861     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
2862   }
2863   if( emptySrcTest ) sqlite3VdbeJumpHere(v, emptySrcTest);
2864   sqlite3ReleaseTempReg(pParse, regRowid);
2865   sqlite3ReleaseTempReg(pParse, regData);
2866   if( emptyDestTest ){
2867     sqlite3AutoincrementEnd(pParse);
2868     sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
2869     sqlite3VdbeJumpHere(v, emptyDestTest);
2870     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
2871     return 0;
2872   }else{
2873     return 1;
2874   }
2875 }
2876 #endif /* SQLITE_OMIT_XFER_OPT */
2877