xref: /sqlite-3.40.0/src/insert.c (revision 666d34c7)
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 */
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   v = sqlite3GetVdbe(pParse);
36   assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
37   sqlite3TableLock(pParse, iDb, pTab->tnum,
38                    (opcode==OP_OpenWrite)?1:0, pTab->zName);
39   if( HasRowid(pTab) ){
40     sqlite3VdbeAddOp4Int(v, opcode, iCur, pTab->tnum, iDb, pTab->nCol);
41     VdbeComment((v, "%s", pTab->zName));
42   }else{
43     Index *pPk = sqlite3PrimaryKeyIndex(pTab);
44     assert( pPk!=0 );
45     assert( pPk->tnum==pTab->tnum );
46     sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);
47     sqlite3VdbeSetP4KeyInfo(pParse, pPk);
48     VdbeComment((v, "%s", pTab->zName));
49   }
50 }
51 
52 /*
53 ** Return a pointer to the column affinity string associated with index
54 ** pIdx. A column affinity string has one character for each column in
55 ** the table, according to the affinity of the column:
56 **
57 **  Character      Column affinity
58 **  ------------------------------
59 **  'A'            BLOB
60 **  'B'            TEXT
61 **  'C'            NUMERIC
62 **  'D'            INTEGER
63 **  'F'            REAL
64 **
65 ** An extra 'D' is appended to the end of the string to cover the
66 ** rowid that appears as the last column in every index.
67 **
68 ** Memory for the buffer containing the column index affinity string
69 ** is managed along with the rest of the Index structure. It will be
70 ** released when sqlite3DeleteIndex() is called.
71 */
72 const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
73   if( !pIdx->zColAff ){
74     /* The first time a column affinity string for a particular index is
75     ** required, it is allocated and populated here. It is then stored as
76     ** a member of the Index structure for subsequent use.
77     **
78     ** The column affinity string will eventually be deleted by
79     ** sqliteDeleteIndex() when the Index structure itself is cleaned
80     ** up.
81     */
82     int n;
83     Table *pTab = pIdx->pTable;
84     pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
85     if( !pIdx->zColAff ){
86       sqlite3OomFault(db);
87       return 0;
88     }
89     for(n=0; n<pIdx->nColumn; n++){
90       i16 x = pIdx->aiColumn[n];
91       if( x>=0 ){
92         pIdx->zColAff[n] = pTab->aCol[x].affinity;
93       }else if( x==XN_ROWID ){
94         pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
95       }else{
96         char aff;
97         assert( x==XN_EXPR );
98         assert( pIdx->aColExpr!=0 );
99         aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
100         if( aff==0 ) aff = SQLITE_AFF_BLOB;
101         pIdx->zColAff[n] = aff;
102       }
103     }
104     pIdx->zColAff[n] = 0;
105   }
106 
107   return pIdx->zColAff;
108 }
109 
110 /*
111 ** Compute the affinity string for table pTab, if it has not already been
112 ** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
113 **
114 ** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and
115 ** if iReg>0 then code an OP_Affinity opcode that will set the affinities
116 ** for register iReg and following.  Or if affinities exists and iReg==0,
117 ** then just set the P4 operand of the previous opcode (which should  be
118 ** an OP_MakeRecord) to the affinity string.
119 **
120 ** A column affinity string has one character per column:
121 **
122 **  Character      Column affinity
123 **  ------------------------------
124 **  'A'            BLOB
125 **  'B'            TEXT
126 **  'C'            NUMERIC
127 **  'D'            INTEGER
128 **  'E'            REAL
129 */
130 void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
131   int i;
132   char *zColAff = pTab->zColAff;
133   if( zColAff==0 ){
134     sqlite3 *db = sqlite3VdbeDb(v);
135     zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
136     if( !zColAff ){
137       sqlite3OomFault(db);
138       return;
139     }
140 
141     for(i=0; i<pTab->nCol; i++){
142       zColAff[i] = pTab->aCol[i].affinity;
143     }
144     do{
145       zColAff[i--] = 0;
146     }while( i>=0 && zColAff[i]==SQLITE_AFF_BLOB );
147     pTab->zColAff = zColAff;
148   }
149   i = sqlite3Strlen30(zColAff);
150   if( i ){
151     if( iReg ){
152       sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);
153     }else{
154       sqlite3VdbeChangeP4(v, -1, zColAff, i);
155     }
156   }
157 }
158 
159 /*
160 ** Return non-zero if the table pTab in database iDb or any of its indices
161 ** have been opened at any point in the VDBE program. This is used to see if
162 ** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can
163 ** run without using a temporary table for the results of the SELECT.
164 */
165 static int readsTable(Parse *p, int iDb, Table *pTab){
166   Vdbe *v = sqlite3GetVdbe(p);
167   int i;
168   int iEnd = sqlite3VdbeCurrentAddr(v);
169 #ifndef SQLITE_OMIT_VIRTUALTABLE
170   VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
171 #endif
172 
173   for(i=1; i<iEnd; i++){
174     VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
175     assert( pOp!=0 );
176     if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
177       Index *pIndex;
178       int tnum = pOp->p2;
179       if( tnum==pTab->tnum ){
180         return 1;
181       }
182       for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
183         if( tnum==pIndex->tnum ){
184           return 1;
185         }
186       }
187     }
188 #ifndef SQLITE_OMIT_VIRTUALTABLE
189     if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){
190       assert( pOp->p4.pVtab!=0 );
191       assert( pOp->p4type==P4_VTAB );
192       return 1;
193     }
194 #endif
195   }
196   return 0;
197 }
198 
199 #ifndef SQLITE_OMIT_AUTOINCREMENT
200 /*
201 ** Locate or create an AutoincInfo structure associated with table pTab
202 ** which is in database iDb.  Return the register number for the register
203 ** that holds the maximum rowid.  Return zero if pTab is not an AUTOINCREMENT
204 ** table.  (Also return zero when doing a VACUUM since we do not want to
205 ** update the AUTOINCREMENT counters during a VACUUM.)
206 **
207 ** There is at most one AutoincInfo structure per table even if the
208 ** same table is autoincremented multiple times due to inserts within
209 ** triggers.  A new AutoincInfo structure is created if this is the
210 ** first use of table pTab.  On 2nd and subsequent uses, the original
211 ** AutoincInfo structure is used.
212 **
213 ** Three memory locations are allocated:
214 **
215 **   (1)  Register to hold the name of the pTab table.
216 **   (2)  Register to hold the maximum ROWID of pTab.
217 **   (3)  Register to hold the rowid in sqlite_sequence of pTab
218 **
219 ** The 2nd register is the one that is returned.  That is all the
220 ** insert routine needs to know about.
221 */
222 static int autoIncBegin(
223   Parse *pParse,      /* Parsing context */
224   int iDb,            /* Index of the database holding pTab */
225   Table *pTab         /* The table we are writing to */
226 ){
227   int memId = 0;      /* Register holding maximum rowid */
228   if( (pTab->tabFlags & TF_Autoincrement)!=0
229    && (pParse->db->flags & SQLITE_Vacuum)==0
230   ){
231     Parse *pToplevel = sqlite3ParseToplevel(pParse);
232     AutoincInfo *pInfo;
233 
234     pInfo = pToplevel->pAinc;
235     while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
236     if( pInfo==0 ){
237       pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));
238       if( pInfo==0 ) return 0;
239       pInfo->pNext = pToplevel->pAinc;
240       pToplevel->pAinc = pInfo;
241       pInfo->pTab = pTab;
242       pInfo->iDb = iDb;
243       pToplevel->nMem++;                  /* Register to hold name of table */
244       pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */
245       pToplevel->nMem++;                  /* Rowid in sqlite_sequence */
246     }
247     memId = pInfo->regCtr;
248   }
249   return memId;
250 }
251 
252 /*
253 ** This routine generates code that will initialize all of the
254 ** register used by the autoincrement tracker.
255 */
256 void sqlite3AutoincrementBegin(Parse *pParse){
257   AutoincInfo *p;            /* Information about an AUTOINCREMENT */
258   sqlite3 *db = pParse->db;  /* The database connection */
259   Db *pDb;                   /* Database only autoinc table */
260   int memId;                 /* Register holding max rowid */
261   Vdbe *v = pParse->pVdbe;   /* VDBE under construction */
262 
263   /* This routine is never called during trigger-generation.  It is
264   ** only called from the top-level */
265   assert( pParse->pTriggerTab==0 );
266   assert( sqlite3IsToplevel(pParse) );
267 
268   assert( v );   /* We failed long ago if this is not so */
269   for(p = pParse->pAinc; p; p = p->pNext){
270     static const int iLn = VDBE_OFFSET_LINENO(2);
271     static const VdbeOpList autoInc[] = {
272       /* 0  */ {OP_Null,    0,  0, 0},
273       /* 1  */ {OP_Rewind,  0,  9, 0},
274       /* 2  */ {OP_Column,  0,  0, 0},
275       /* 3  */ {OP_Ne,      0,  7, 0},
276       /* 4  */ {OP_Rowid,   0,  0, 0},
277       /* 5  */ {OP_Column,  0,  1, 0},
278       /* 6  */ {OP_Goto,    0,  9, 0},
279       /* 7  */ {OP_Next,    0,  2, 0},
280       /* 8  */ {OP_Integer, 0,  0, 0},
281       /* 9  */ {OP_Close,   0,  0, 0}
282     };
283     VdbeOp *aOp;
284     pDb = &db->aDb[p->iDb];
285     memId = p->regCtr;
286     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
287     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
288     sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
289     aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);
290     if( aOp==0 ) break;
291     aOp[0].p2 = memId;
292     aOp[0].p3 = memId+1;
293     aOp[2].p3 = memId;
294     aOp[3].p1 = memId-1;
295     aOp[3].p3 = memId;
296     aOp[3].p5 = SQLITE_JUMPIFNULL;
297     aOp[4].p2 = memId+1;
298     aOp[5].p3 = memId;
299     aOp[8].p2 = memId;
300   }
301 }
302 
303 /*
304 ** Update the maximum rowid for an autoincrement calculation.
305 **
306 ** This routine should be called when the regRowid register holds a
307 ** new rowid that is about to be inserted.  If that new rowid is
308 ** larger than the maximum rowid in the memId memory cell, then the
309 ** memory cell is updated.
310 */
311 static void autoIncStep(Parse *pParse, int memId, int regRowid){
312   if( memId>0 ){
313     sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
314   }
315 }
316 
317 /*
318 ** This routine generates the code needed to write autoincrement
319 ** maximum rowid values back into the sqlite_sequence register.
320 ** Every statement that might do an INSERT into an autoincrement
321 ** table (either directly or through triggers) needs to call this
322 ** routine just before the "exit" code.
323 */
324 static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){
325   AutoincInfo *p;
326   Vdbe *v = pParse->pVdbe;
327   sqlite3 *db = pParse->db;
328 
329   assert( v );
330   for(p = pParse->pAinc; p; p = p->pNext){
331     static const int iLn = VDBE_OFFSET_LINENO(2);
332     static const VdbeOpList autoIncEnd[] = {
333       /* 0 */ {OP_NotNull,     0, 2, 0},
334       /* 1 */ {OP_NewRowid,    0, 0, 0},
335       /* 2 */ {OP_MakeRecord,  0, 2, 0},
336       /* 3 */ {OP_Insert,      0, 0, 0},
337       /* 4 */ {OP_Close,       0, 0, 0}
338     };
339     VdbeOp *aOp;
340     Db *pDb = &db->aDb[p->iDb];
341     int iRec;
342     int memId = p->regCtr;
343 
344     iRec = sqlite3GetTempReg(pParse);
345     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
346     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
347     aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);
348     if( aOp==0 ) break;
349     aOp[0].p1 = memId+1;
350     aOp[1].p2 = memId+1;
351     aOp[2].p1 = memId-1;
352     aOp[2].p3 = iRec;
353     aOp[3].p2 = iRec;
354     aOp[3].p3 = memId+1;
355     aOp[3].p5 = OPFLAG_APPEND;
356     sqlite3ReleaseTempReg(pParse, iRec);
357   }
358 }
359 void sqlite3AutoincrementEnd(Parse *pParse){
360   if( pParse->pAinc ) autoIncrementEnd(pParse);
361 }
362 #else
363 /*
364 ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
365 ** above are all no-ops
366 */
367 # define autoIncBegin(A,B,C) (0)
368 # define autoIncStep(A,B,C)
369 #endif /* SQLITE_OMIT_AUTOINCREMENT */
370 
371 
372 /* Forward declaration */
373 static int xferOptimization(
374   Parse *pParse,        /* Parser context */
375   Table *pDest,         /* The table we are inserting into */
376   Select *pSelect,      /* A SELECT statement to use as the data source */
377   int onError,          /* How to handle constraint errors */
378   int iDbDest           /* The database of pDest */
379 );
380 
381 /*
382 ** This routine is called to handle SQL of the following forms:
383 **
384 **    insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
385 **    insert into TABLE (IDLIST) select
386 **    insert into TABLE (IDLIST) default values
387 **
388 ** The IDLIST following the table name is always optional.  If omitted,
389 ** then a list of all (non-hidden) columns for the table is substituted.
390 ** The IDLIST appears in the pColumn parameter.  pColumn is NULL if IDLIST
391 ** is omitted.
392 **
393 ** For the pSelect parameter holds the values to be inserted for the
394 ** first two forms shown above.  A VALUES clause is really just short-hand
395 ** for a SELECT statement that omits the FROM clause and everything else
396 ** that follows.  If the pSelect parameter is NULL, that means that the
397 ** DEFAULT VALUES form of the INSERT statement is intended.
398 **
399 ** The code generated follows one of four templates.  For a simple
400 ** insert with data coming from a single-row VALUES clause, the code executes
401 ** once straight down through.  Pseudo-code follows (we call this
402 ** the "1st template"):
403 **
404 **         open write cursor to <table> and its indices
405 **         put VALUES clause expressions into registers
406 **         write the resulting record into <table>
407 **         cleanup
408 **
409 ** The three remaining templates assume the statement is of the form
410 **
411 **   INSERT INTO <table> SELECT ...
412 **
413 ** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
414 ** in other words if the SELECT pulls all columns from a single table
415 ** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
416 ** if <table2> and <table1> are distinct tables but have identical
417 ** schemas, including all the same indices, then a special optimization
418 ** is invoked that copies raw records from <table2> over to <table1>.
419 ** See the xferOptimization() function for the implementation of this
420 ** template.  This is the 2nd template.
421 **
422 **         open a write cursor to <table>
423 **         open read cursor on <table2>
424 **         transfer all records in <table2> over to <table>
425 **         close cursors
426 **         foreach index on <table>
427 **           open a write cursor on the <table> index
428 **           open a read cursor on the corresponding <table2> index
429 **           transfer all records from the read to the write cursors
430 **           close cursors
431 **         end foreach
432 **
433 ** The 3rd template is for when the second template does not apply
434 ** and the SELECT clause does not read from <table> at any time.
435 ** The generated code follows this template:
436 **
437 **         X <- A
438 **         goto B
439 **      A: setup for the SELECT
440 **         loop over the rows in the SELECT
441 **           load values into registers R..R+n
442 **           yield X
443 **         end loop
444 **         cleanup after the SELECT
445 **         end-coroutine X
446 **      B: open write cursor to <table> and its indices
447 **      C: yield X, at EOF goto D
448 **         insert the select result into <table> from R..R+n
449 **         goto C
450 **      D: cleanup
451 **
452 ** The 4th template is used if the insert statement takes its
453 ** values from a SELECT but the data is being inserted into a table
454 ** that is also read as part of the SELECT.  In the third form,
455 ** we have to use an intermediate table to store the results of
456 ** the select.  The template is like this:
457 **
458 **         X <- A
459 **         goto B
460 **      A: setup for the SELECT
461 **         loop over the tables in the SELECT
462 **           load value into register R..R+n
463 **           yield X
464 **         end loop
465 **         cleanup after the SELECT
466 **         end co-routine R
467 **      B: open temp table
468 **      L: yield X, at EOF goto M
469 **         insert row from R..R+n into temp table
470 **         goto L
471 **      M: open write cursor to <table> and its indices
472 **         rewind temp table
473 **      C: loop over rows of intermediate table
474 **           transfer values form intermediate table into <table>
475 **         end loop
476 **      D: cleanup
477 */
478 void sqlite3Insert(
479   Parse *pParse,        /* Parser context */
480   SrcList *pTabList,    /* Name of table into which we are inserting */
481   Select *pSelect,      /* A SELECT statement to use as the data source */
482   IdList *pColumn,      /* Column names corresponding to IDLIST. */
483   int onError           /* How to handle constraint errors */
484 ){
485   sqlite3 *db;          /* The main database structure */
486   Table *pTab;          /* The table to insert into.  aka TABLE */
487   char *zTab;           /* Name of the table into which we are inserting */
488   int i, j;             /* Loop counters */
489   Vdbe *v;              /* Generate code into this virtual machine */
490   Index *pIdx;          /* For looping over indices of the table */
491   int nColumn;          /* Number of columns in the data */
492   int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */
493   int iDataCur = 0;     /* VDBE cursor that is the main data repository */
494   int iIdxCur = 0;      /* First index cursor */
495   int ipkColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
496   int endOfLoop;        /* Label for the end of the insertion loop */
497   int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
498   int addrInsTop = 0;   /* Jump to label "D" */
499   int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
500   SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
501   int iDb;              /* Index of database holding TABLE */
502   u8 useTempTable = 0;  /* Store SELECT results in intermediate table */
503   u8 appendFlag = 0;    /* True if the insert is likely to be an append */
504   u8 withoutRowid;      /* 0 for normal table.  1 for WITHOUT ROWID table */
505   u8 bIdListInOrder;    /* True if IDLIST is in table order */
506   ExprList *pList = 0;  /* List of VALUES() to be inserted  */
507 
508   /* Register allocations */
509   int regFromSelect = 0;/* Base register for data coming from SELECT */
510   int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
511   int regRowCount = 0;  /* Memory cell used for the row counter */
512   int regIns;           /* Block of regs holding rowid+data being inserted */
513   int regRowid;         /* registers holding insert rowid */
514   int regData;          /* register holding first column to insert */
515   int *aRegIdx = 0;     /* One register allocated to each index */
516 
517 #ifndef SQLITE_OMIT_TRIGGER
518   int isView;                 /* True if attempting to insert into a view */
519   Trigger *pTrigger;          /* List of triggers on pTab, if required */
520   int tmask;                  /* Mask of trigger times */
521 #endif
522 
523   db = pParse->db;
524   memset(&dest, 0, sizeof(dest));
525   if( pParse->nErr || db->mallocFailed ){
526     goto insert_cleanup;
527   }
528 
529   /* If the Select object is really just a simple VALUES() list with a
530   ** single row (the common case) then keep that one row of values
531   ** and discard the other (unused) parts of the pSelect object
532   */
533   if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){
534     pList = pSelect->pEList;
535     pSelect->pEList = 0;
536     sqlite3SelectDelete(db, pSelect);
537     pSelect = 0;
538   }
539 
540   /* Locate the table into which we will be inserting new information.
541   */
542   assert( pTabList->nSrc==1 );
543   zTab = pTabList->a[0].zName;
544   if( NEVER(zTab==0) ) goto insert_cleanup;
545   pTab = sqlite3SrcListLookup(pParse, pTabList);
546   if( pTab==0 ){
547     goto insert_cleanup;
548   }
549   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
550   assert( iDb<db->nDb );
551   if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0,
552                        db->aDb[iDb].zDbSName) ){
553     goto insert_cleanup;
554   }
555   withoutRowid = !HasRowid(pTab);
556 
557   /* Figure out if we have any triggers and if the table being
558   ** inserted into is a view
559   */
560 #ifndef SQLITE_OMIT_TRIGGER
561   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
562   isView = pTab->pSelect!=0;
563 #else
564 # define pTrigger 0
565 # define tmask 0
566 # define isView 0
567 #endif
568 #ifdef SQLITE_OMIT_VIEW
569 # undef isView
570 # define isView 0
571 #endif
572   assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );
573 
574   /* If pTab is really a view, make sure it has been initialized.
575   ** ViewGetColumnNames() is a no-op if pTab is not a view.
576   */
577   if( sqlite3ViewGetColumnNames(pParse, pTab) ){
578     goto insert_cleanup;
579   }
580 
581   /* Cannot insert into a read-only table.
582   */
583   if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
584     goto insert_cleanup;
585   }
586 
587   /* Allocate a VDBE
588   */
589   v = sqlite3GetVdbe(pParse);
590   if( v==0 ) goto insert_cleanup;
591   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
592   sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);
593 
594 #ifndef SQLITE_OMIT_XFER_OPT
595   /* If the statement is of the form
596   **
597   **       INSERT INTO <table1> SELECT * FROM <table2>;
598   **
599   ** Then special optimizations can be applied that make the transfer
600   ** very fast and which reduce fragmentation of indices.
601   **
602   ** This is the 2nd template.
603   */
604   if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
605     assert( !pTrigger );
606     assert( pList==0 );
607     goto insert_end;
608   }
609 #endif /* SQLITE_OMIT_XFER_OPT */
610 
611   /* If this is an AUTOINCREMENT table, look up the sequence number in the
612   ** sqlite_sequence table and store it in memory cell regAutoinc.
613   */
614   regAutoinc = autoIncBegin(pParse, iDb, pTab);
615 
616   /* Allocate registers for holding the rowid of the new row,
617   ** the content of the new row, and the assembled row record.
618   */
619   regRowid = regIns = pParse->nMem+1;
620   pParse->nMem += pTab->nCol + 1;
621   if( IsVirtual(pTab) ){
622     regRowid++;
623     pParse->nMem++;
624   }
625   regData = regRowid+1;
626 
627   /* If the INSERT statement included an IDLIST term, then make sure
628   ** all elements of the IDLIST really are columns of the table and
629   ** remember the column indices.
630   **
631   ** If the table has an INTEGER PRIMARY KEY column and that column
632   ** is named in the IDLIST, then record in the ipkColumn variable
633   ** the index into IDLIST of the primary key column.  ipkColumn is
634   ** the index of the primary key as it appears in IDLIST, not as
635   ** is appears in the original table.  (The index of the INTEGER
636   ** PRIMARY KEY in the original table is pTab->iPKey.)
637   */
638   bIdListInOrder = (pTab->tabFlags & TF_OOOHidden)==0;
639   if( pColumn ){
640     for(i=0; i<pColumn->nId; i++){
641       pColumn->a[i].idx = -1;
642     }
643     for(i=0; i<pColumn->nId; i++){
644       for(j=0; j<pTab->nCol; j++){
645         if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
646           pColumn->a[i].idx = j;
647           if( i!=j ) bIdListInOrder = 0;
648           if( j==pTab->iPKey ){
649             ipkColumn = i;  assert( !withoutRowid );
650           }
651           break;
652         }
653       }
654       if( j>=pTab->nCol ){
655         if( sqlite3IsRowid(pColumn->a[i].zName) && !withoutRowid ){
656           ipkColumn = i;
657           bIdListInOrder = 0;
658         }else{
659           sqlite3ErrorMsg(pParse, "table %S has no column named %s",
660               pTabList, 0, pColumn->a[i].zName);
661           pParse->checkSchema = 1;
662           goto insert_cleanup;
663         }
664       }
665     }
666   }
667 
668   /* Figure out how many columns of data are supplied.  If the data
669   ** is coming from a SELECT statement, then generate a co-routine that
670   ** produces a single row of the SELECT on each invocation.  The
671   ** co-routine is the common header to the 3rd and 4th templates.
672   */
673   if( pSelect ){
674     /* Data is coming from a SELECT or from a multi-row VALUES clause.
675     ** Generate a co-routine to run the SELECT. */
676     int regYield;       /* Register holding co-routine entry-point */
677     int addrTop;        /* Top of the co-routine */
678     int rc;             /* Result code */
679 
680     regYield = ++pParse->nMem;
681     addrTop = sqlite3VdbeCurrentAddr(v) + 1;
682     sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
683     sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
684     dest.iSdst = bIdListInOrder ? regData : 0;
685     dest.nSdst = pTab->nCol;
686     rc = sqlite3Select(pParse, pSelect, &dest);
687     regFromSelect = dest.iSdst;
688     if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;
689     sqlite3VdbeEndCoroutine(v, regYield);
690     sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */
691     assert( pSelect->pEList );
692     nColumn = pSelect->pEList->nExpr;
693 
694     /* Set useTempTable to TRUE if the result of the SELECT statement
695     ** should be written into a temporary table (template 4).  Set to
696     ** FALSE if each output row of the SELECT can be written directly into
697     ** the destination table (template 3).
698     **
699     ** A temp table must be used if the table being updated is also one
700     ** of the tables being read by the SELECT statement.  Also use a
701     ** temp table in the case of row triggers.
702     */
703     if( pTrigger || readsTable(pParse, iDb, pTab) ){
704       useTempTable = 1;
705     }
706 
707     if( useTempTable ){
708       /* Invoke the coroutine to extract information from the SELECT
709       ** and add it to a transient table srcTab.  The code generated
710       ** here is from the 4th template:
711       **
712       **      B: open temp table
713       **      L: yield X, goto M at EOF
714       **         insert row from R..R+n into temp table
715       **         goto L
716       **      M: ...
717       */
718       int regRec;          /* Register to hold packed record */
719       int regTempRowid;    /* Register to hold temp table ROWID */
720       int addrL;           /* Label "L" */
721 
722       srcTab = pParse->nTab++;
723       regRec = sqlite3GetTempReg(pParse);
724       regTempRowid = sqlite3GetTempReg(pParse);
725       sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
726       addrL = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); VdbeCoverage(v);
727       sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
728       sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
729       sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
730       sqlite3VdbeGoto(v, addrL);
731       sqlite3VdbeJumpHere(v, addrL);
732       sqlite3ReleaseTempReg(pParse, regRec);
733       sqlite3ReleaseTempReg(pParse, regTempRowid);
734     }
735   }else{
736     /* This is the case if the data for the INSERT is coming from a
737     ** single-row VALUES clause
738     */
739     NameContext sNC;
740     memset(&sNC, 0, sizeof(sNC));
741     sNC.pParse = pParse;
742     srcTab = -1;
743     assert( useTempTable==0 );
744     if( pList ){
745       nColumn = pList->nExpr;
746       if( sqlite3ResolveExprListNames(&sNC, pList) ){
747         goto insert_cleanup;
748       }
749     }else{
750       nColumn = 0;
751     }
752   }
753 
754   /* If there is no IDLIST term but the table has an integer primary
755   ** key, the set the ipkColumn variable to the integer primary key
756   ** column index in the original table definition.
757   */
758   if( pColumn==0 && nColumn>0 ){
759     ipkColumn = pTab->iPKey;
760   }
761 
762   /* Make sure the number of columns in the source data matches the number
763   ** of columns to be inserted into the table.
764   */
765   for(i=0; i<pTab->nCol; i++){
766     nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
767   }
768   if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
769     sqlite3ErrorMsg(pParse,
770        "table %S has %d columns but %d values were supplied",
771        pTabList, 0, pTab->nCol-nHidden, nColumn);
772     goto insert_cleanup;
773   }
774   if( pColumn!=0 && nColumn!=pColumn->nId ){
775     sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
776     goto insert_cleanup;
777   }
778 
779   /* Initialize the count of rows to be inserted
780   */
781   if( db->flags & SQLITE_CountRows ){
782     regRowCount = ++pParse->nMem;
783     sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
784   }
785 
786   /* If this is not a view, open the table and and all indices */
787   if( !isView ){
788     int nIdx;
789     nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
790                                       &iDataCur, &iIdxCur);
791     aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+1));
792     if( aRegIdx==0 ){
793       goto insert_cleanup;
794     }
795     for(i=0, pIdx=pTab->pIndex; i<nIdx; pIdx=pIdx->pNext, i++){
796       assert( pIdx );
797       aRegIdx[i] = ++pParse->nMem;
798       pParse->nMem += pIdx->nColumn;
799     }
800   }
801 
802   /* This is the top of the main insertion loop */
803   if( useTempTable ){
804     /* This block codes the top of loop only.  The complete loop is the
805     ** following pseudocode (template 4):
806     **
807     **         rewind temp table, if empty goto D
808     **      C: loop over rows of intermediate table
809     **           transfer values form intermediate table into <table>
810     **         end loop
811     **      D: ...
812     */
813     addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab); VdbeCoverage(v);
814     addrCont = sqlite3VdbeCurrentAddr(v);
815   }else if( pSelect ){
816     /* This block codes the top of loop only.  The complete loop is the
817     ** following pseudocode (template 3):
818     **
819     **      C: yield X, at EOF goto D
820     **         insert the select result into <table> from R..R+n
821     **         goto C
822     **      D: ...
823     */
824     addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
825     VdbeCoverage(v);
826   }
827 
828   /* Run the BEFORE and INSTEAD OF triggers, if there are any
829   */
830   endOfLoop = sqlite3VdbeMakeLabel(v);
831   if( tmask & TRIGGER_BEFORE ){
832     int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);
833 
834     /* build the NEW.* reference row.  Note that if there is an INTEGER
835     ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
836     ** translated into a unique ID for the row.  But on a BEFORE trigger,
837     ** we do not know what the unique ID will be (because the insert has
838     ** not happened yet) so we substitute a rowid of -1
839     */
840     if( ipkColumn<0 ){
841       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
842     }else{
843       int addr1;
844       assert( !withoutRowid );
845       if( useTempTable ){
846         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);
847       }else{
848         assert( pSelect==0 );  /* Otherwise useTempTable is true */
849         sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);
850       }
851       addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
852       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
853       sqlite3VdbeJumpHere(v, addr1);
854       sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
855     }
856 
857     /* Cannot have triggers on a virtual table. If it were possible,
858     ** this block would have to account for hidden column.
859     */
860     assert( !IsVirtual(pTab) );
861 
862     /* Create the new column data
863     */
864     for(i=j=0; i<pTab->nCol; i++){
865       if( pColumn ){
866         for(j=0; j<pColumn->nId; j++){
867           if( pColumn->a[j].idx==i ) break;
868         }
869       }
870       if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId)
871             || (pColumn==0 && IsOrdinaryHiddenColumn(&pTab->aCol[i])) ){
872         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);
873       }else if( useTempTable ){
874         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1);
875       }else{
876         assert( pSelect==0 ); /* Otherwise useTempTable is true */
877         sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);
878       }
879       if( pColumn==0 && !IsOrdinaryHiddenColumn(&pTab->aCol[i]) ) j++;
880     }
881 
882     /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
883     ** do not attempt any conversions before assembling the record.
884     ** If this is a real table, attempt conversions as required by the
885     ** table column affinities.
886     */
887     if( !isView ){
888       sqlite3TableAffinity(v, pTab, regCols+1);
889     }
890 
891     /* Fire BEFORE or INSTEAD OF triggers */
892     sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE,
893         pTab, regCols-pTab->nCol-1, onError, endOfLoop);
894 
895     sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
896   }
897 
898   /* Compute the content of the next row to insert into a range of
899   ** registers beginning at regIns.
900   */
901   if( !isView ){
902     if( IsVirtual(pTab) ){
903       /* The row that the VUpdate opcode will delete: none */
904       sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
905     }
906     if( ipkColumn>=0 ){
907       if( useTempTable ){
908         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
909       }else if( pSelect ){
910         sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
911       }else{
912         VdbeOp *pOp;
913         sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
914         pOp = sqlite3VdbeGetOp(v, -1);
915         if( ALWAYS(pOp) && pOp->opcode==OP_Null && !IsVirtual(pTab) ){
916           appendFlag = 1;
917           pOp->opcode = OP_NewRowid;
918           pOp->p1 = iDataCur;
919           pOp->p2 = regRowid;
920           pOp->p3 = regAutoinc;
921         }
922       }
923       /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
924       ** to generate a unique primary key value.
925       */
926       if( !appendFlag ){
927         int addr1;
928         if( !IsVirtual(pTab) ){
929           addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
930           sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
931           sqlite3VdbeJumpHere(v, addr1);
932         }else{
933           addr1 = sqlite3VdbeCurrentAddr(v);
934           sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);
935         }
936         sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);
937       }
938     }else if( IsVirtual(pTab) || withoutRowid ){
939       sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
940     }else{
941       sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
942       appendFlag = 1;
943     }
944     autoIncStep(pParse, regAutoinc, regRowid);
945 
946     /* Compute data for all columns of the new entry, beginning
947     ** with the first column.
948     */
949     nHidden = 0;
950     for(i=0; i<pTab->nCol; i++){
951       int iRegStore = regRowid+1+i;
952       if( i==pTab->iPKey ){
953         /* The value of the INTEGER PRIMARY KEY column is always a NULL.
954         ** Whenever this column is read, the rowid will be substituted
955         ** in its place.  Hence, fill this column with a NULL to avoid
956         ** taking up data space with information that will never be used.
957         ** As there may be shallow copies of this value, make it a soft-NULL */
958         sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
959         continue;
960       }
961       if( pColumn==0 ){
962         if( IsHiddenColumn(&pTab->aCol[i]) ){
963           j = -1;
964           nHidden++;
965         }else{
966           j = i - nHidden;
967         }
968       }else{
969         for(j=0; j<pColumn->nId; j++){
970           if( pColumn->a[j].idx==i ) break;
971         }
972       }
973       if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
974         sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
975       }else if( useTempTable ){
976         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore);
977       }else if( pSelect ){
978         if( regFromSelect!=regData ){
979           sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
980         }
981       }else{
982         sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);
983       }
984     }
985 
986     /* Generate code to check constraints and generate index keys and
987     ** do the insertion.
988     */
989 #ifndef SQLITE_OMIT_VIRTUALTABLE
990     if( IsVirtual(pTab) ){
991       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
992       sqlite3VtabMakeWritable(pParse, pTab);
993       sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
994       sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
995       sqlite3MayAbort(pParse);
996     }else
997 #endif
998     {
999       int isReplace;    /* Set to true if constraints may cause a replace */
1000       int bUseSeek;     /* True to use OPFLAG_SEEKRESULT */
1001       sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
1002           regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0
1003       );
1004       sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
1005 
1006       /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
1007       ** constraints or (b) there are no triggers and this table is not a
1008       ** parent table in a foreign key constraint. It is safe to set the
1009       ** flag in the second case as if any REPLACE constraint is hit, an
1010       ** OP_Delete or OP_IdxDelete instruction will be executed on each
1011       ** cursor that is disturbed. And these instructions both clear the
1012       ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
1013       ** functionality.  */
1014       bUseSeek = (isReplace==0 || (pTrigger==0 &&
1015           ((db->flags & SQLITE_ForeignKeys)==0 || sqlite3FkReferences(pTab)==0)
1016       ));
1017       sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
1018           regIns, aRegIdx, 0, appendFlag, bUseSeek
1019       );
1020     }
1021   }
1022 
1023   /* Update the count of rows that are inserted
1024   */
1025   if( (db->flags & SQLITE_CountRows)!=0 ){
1026     sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
1027   }
1028 
1029   if( pTrigger ){
1030     /* Code AFTER triggers */
1031     sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER,
1032         pTab, regData-2-pTab->nCol, onError, endOfLoop);
1033   }
1034 
1035   /* The bottom of the main insertion loop, if the data source
1036   ** is a SELECT statement.
1037   */
1038   sqlite3VdbeResolveLabel(v, endOfLoop);
1039   if( useTempTable ){
1040     sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont); VdbeCoverage(v);
1041     sqlite3VdbeJumpHere(v, addrInsTop);
1042     sqlite3VdbeAddOp1(v, OP_Close, srcTab);
1043   }else if( pSelect ){
1044     sqlite3VdbeGoto(v, addrCont);
1045     sqlite3VdbeJumpHere(v, addrInsTop);
1046   }
1047 
1048 insert_end:
1049   /* Update the sqlite_sequence table by storing the content of the
1050   ** maximum rowid counter values recorded while inserting into
1051   ** autoincrement tables.
1052   */
1053   if( pParse->nested==0 && pParse->pTriggerTab==0 ){
1054     sqlite3AutoincrementEnd(pParse);
1055   }
1056 
1057   /*
1058   ** Return the number of rows inserted. If this routine is
1059   ** generating code because of a call to sqlite3NestedParse(), do not
1060   ** invoke the callback function.
1061   */
1062   if( (db->flags&SQLITE_CountRows) && !pParse->nested && !pParse->pTriggerTab ){
1063     sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
1064     sqlite3VdbeSetNumCols(v, 1);
1065     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", SQLITE_STATIC);
1066   }
1067 
1068 insert_cleanup:
1069   sqlite3SrcListDelete(db, pTabList);
1070   sqlite3ExprListDelete(db, pList);
1071   sqlite3SelectDelete(db, pSelect);
1072   sqlite3IdListDelete(db, pColumn);
1073   sqlite3DbFree(db, aRegIdx);
1074 }
1075 
1076 /* Make sure "isView" and other macros defined above are undefined. Otherwise
1077 ** they may interfere with compilation of other functions in this file
1078 ** (or in another file, if this file becomes part of the amalgamation).  */
1079 #ifdef isView
1080  #undef isView
1081 #endif
1082 #ifdef pTrigger
1083  #undef pTrigger
1084 #endif
1085 #ifdef tmask
1086  #undef tmask
1087 #endif
1088 
1089 /*
1090 ** Meanings of bits in of pWalker->eCode for checkConstraintUnchanged()
1091 */
1092 #define CKCNSTRNT_COLUMN   0x01    /* CHECK constraint uses a changing column */
1093 #define CKCNSTRNT_ROWID    0x02    /* CHECK constraint references the ROWID */
1094 
1095 /* This is the Walker callback from checkConstraintUnchanged().  Set
1096 ** bit 0x01 of pWalker->eCode if
1097 ** pWalker->eCode to 0 if this expression node references any of the
1098 ** columns that are being modifed by an UPDATE statement.
1099 */
1100 static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
1101   if( pExpr->op==TK_COLUMN ){
1102     assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );
1103     if( pExpr->iColumn>=0 ){
1104       if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){
1105         pWalker->eCode |= CKCNSTRNT_COLUMN;
1106       }
1107     }else{
1108       pWalker->eCode |= CKCNSTRNT_ROWID;
1109     }
1110   }
1111   return WRC_Continue;
1112 }
1113 
1114 /*
1115 ** pExpr is a CHECK constraint on a row that is being UPDATE-ed.  The
1116 ** only columns that are modified by the UPDATE are those for which
1117 ** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
1118 **
1119 ** Return true if CHECK constraint pExpr does not use any of the
1120 ** changing columns (or the rowid if it is changing).  In other words,
1121 ** return true if this CHECK constraint can be skipped when validating
1122 ** the new row in the UPDATE statement.
1123 */
1124 static int checkConstraintUnchanged(Expr *pExpr, int *aiChng, int chngRowid){
1125   Walker w;
1126   memset(&w, 0, sizeof(w));
1127   w.eCode = 0;
1128   w.xExprCallback = checkConstraintExprNode;
1129   w.u.aiCol = aiChng;
1130   sqlite3WalkExpr(&w, pExpr);
1131   if( !chngRowid ){
1132     testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );
1133     w.eCode &= ~CKCNSTRNT_ROWID;
1134   }
1135   testcase( w.eCode==0 );
1136   testcase( w.eCode==CKCNSTRNT_COLUMN );
1137   testcase( w.eCode==CKCNSTRNT_ROWID );
1138   testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );
1139   return !w.eCode;
1140 }
1141 
1142 /*
1143 ** Generate code to do constraint checks prior to an INSERT or an UPDATE
1144 ** on table pTab.
1145 **
1146 ** The regNewData parameter is the first register in a range that contains
1147 ** the data to be inserted or the data after the update.  There will be
1148 ** pTab->nCol+1 registers in this range.  The first register (the one
1149 ** that regNewData points to) will contain the new rowid, or NULL in the
1150 ** case of a WITHOUT ROWID table.  The second register in the range will
1151 ** contain the content of the first table column.  The third register will
1152 ** contain the content of the second table column.  And so forth.
1153 **
1154 ** The regOldData parameter is similar to regNewData except that it contains
1155 ** the data prior to an UPDATE rather than afterwards.  regOldData is zero
1156 ** for an INSERT.  This routine can distinguish between UPDATE and INSERT by
1157 ** checking regOldData for zero.
1158 **
1159 ** For an UPDATE, the pkChng boolean is true if the true primary key (the
1160 ** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
1161 ** might be modified by the UPDATE.  If pkChng is false, then the key of
1162 ** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
1163 **
1164 ** For an INSERT, the pkChng boolean indicates whether or not the rowid
1165 ** was explicitly specified as part of the INSERT statement.  If pkChng
1166 ** is zero, it means that the either rowid is computed automatically or
1167 ** that the table is a WITHOUT ROWID table and has no rowid.  On an INSERT,
1168 ** pkChng will only be true if the INSERT statement provides an integer
1169 ** value for either the rowid column or its INTEGER PRIMARY KEY alias.
1170 **
1171 ** The code generated by this routine will store new index entries into
1172 ** registers identified by aRegIdx[].  No index entry is created for
1173 ** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
1174 ** the same as the order of indices on the linked list of indices
1175 ** at pTab->pIndex.
1176 **
1177 ** The caller must have already opened writeable cursors on the main
1178 ** table and all applicable indices (that is to say, all indices for which
1179 ** aRegIdx[] is not zero).  iDataCur is the cursor for the main table when
1180 ** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
1181 ** index when operating on a WITHOUT ROWID table.  iIdxCur is the cursor
1182 ** for the first index in the pTab->pIndex list.  Cursors for other indices
1183 ** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
1184 **
1185 ** This routine also generates code to check constraints.  NOT NULL,
1186 ** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
1187 ** then the appropriate action is performed.  There are five possible
1188 ** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
1189 **
1190 **  Constraint type  Action       What Happens
1191 **  ---------------  ----------   ----------------------------------------
1192 **  any              ROLLBACK     The current transaction is rolled back and
1193 **                                sqlite3_step() returns immediately with a
1194 **                                return code of SQLITE_CONSTRAINT.
1195 **
1196 **  any              ABORT        Back out changes from the current command
1197 **                                only (do not do a complete rollback) then
1198 **                                cause sqlite3_step() to return immediately
1199 **                                with SQLITE_CONSTRAINT.
1200 **
1201 **  any              FAIL         Sqlite3_step() returns immediately with a
1202 **                                return code of SQLITE_CONSTRAINT.  The
1203 **                                transaction is not rolled back and any
1204 **                                changes to prior rows are retained.
1205 **
1206 **  any              IGNORE       The attempt in insert or update the current
1207 **                                row is skipped, without throwing an error.
1208 **                                Processing continues with the next row.
1209 **                                (There is an immediate jump to ignoreDest.)
1210 **
1211 **  NOT NULL         REPLACE      The NULL value is replace by the default
1212 **                                value for that column.  If the default value
1213 **                                is NULL, the action is the same as ABORT.
1214 **
1215 **  UNIQUE           REPLACE      The other row that conflicts with the row
1216 **                                being inserted is removed.
1217 **
1218 **  CHECK            REPLACE      Illegal.  The results in an exception.
1219 **
1220 ** Which action to take is determined by the overrideError parameter.
1221 ** Or if overrideError==OE_Default, then the pParse->onError parameter
1222 ** is used.  Or if pParse->onError==OE_Default then the onError value
1223 ** for the constraint is used.
1224 */
1225 void sqlite3GenerateConstraintChecks(
1226   Parse *pParse,       /* The parser context */
1227   Table *pTab,         /* The table being inserted or updated */
1228   int *aRegIdx,        /* Use register aRegIdx[i] for index i.  0 for unused */
1229   int iDataCur,        /* Canonical data cursor (main table or PK index) */
1230   int iIdxCur,         /* First index cursor */
1231   int regNewData,      /* First register in a range holding values to insert */
1232   int regOldData,      /* Previous content.  0 for INSERTs */
1233   u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */
1234   u8 overrideError,    /* Override onError to this if not OE_Default */
1235   int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
1236   int *pbMayReplace,   /* OUT: Set to true if constraint may cause a replace */
1237   int *aiChng          /* column i is unchanged if aiChng[i]<0 */
1238 ){
1239   Vdbe *v;             /* VDBE under constrution */
1240   Index *pIdx;         /* Pointer to one of the indices */
1241   Index *pPk = 0;      /* The PRIMARY KEY index */
1242   sqlite3 *db;         /* Database connection */
1243   int i;               /* loop counter */
1244   int ix;              /* Index loop counter */
1245   int nCol;            /* Number of columns */
1246   int onError;         /* Conflict resolution strategy */
1247   int addr1;           /* Address of jump instruction */
1248   int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
1249   int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
1250   int ipkTop = 0;      /* Top of the rowid change constraint check */
1251   int ipkBottom = 0;   /* Bottom of the rowid change constraint check */
1252   u8 isUpdate;         /* True if this is an UPDATE operation */
1253   u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
1254 
1255   isUpdate = regOldData!=0;
1256   db = pParse->db;
1257   v = sqlite3GetVdbe(pParse);
1258   assert( v!=0 );
1259   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
1260   nCol = pTab->nCol;
1261 
1262   /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
1263   ** normal rowid tables.  nPkField is the number of key fields in the
1264   ** pPk index or 1 for a rowid table.  In other words, nPkField is the
1265   ** number of fields in the true primary key of the table. */
1266   if( HasRowid(pTab) ){
1267     pPk = 0;
1268     nPkField = 1;
1269   }else{
1270     pPk = sqlite3PrimaryKeyIndex(pTab);
1271     nPkField = pPk->nKeyCol;
1272   }
1273 
1274   /* Record that this module has started */
1275   VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
1276                      iDataCur, iIdxCur, regNewData, regOldData, pkChng));
1277 
1278   /* Test all NOT NULL constraints.
1279   */
1280   for(i=0; i<nCol; i++){
1281     if( i==pTab->iPKey ){
1282       continue;        /* ROWID is never NULL */
1283     }
1284     if( aiChng && aiChng[i]<0 ){
1285       /* Don't bother checking for NOT NULL on columns that do not change */
1286       continue;
1287     }
1288     onError = pTab->aCol[i].notNull;
1289     if( onError==OE_None ) continue;  /* This column is allowed to be NULL */
1290     if( overrideError!=OE_Default ){
1291       onError = overrideError;
1292     }else if( onError==OE_Default ){
1293       onError = OE_Abort;
1294     }
1295     if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
1296       onError = OE_Abort;
1297     }
1298     assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1299         || onError==OE_Ignore || onError==OE_Replace );
1300     switch( onError ){
1301       case OE_Abort:
1302         sqlite3MayAbort(pParse);
1303         /* Fall through */
1304       case OE_Rollback:
1305       case OE_Fail: {
1306         char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
1307                                     pTab->aCol[i].zName);
1308         sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL, onError,
1309                           regNewData+1+i);
1310         sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);
1311         sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
1312         VdbeCoverage(v);
1313         break;
1314       }
1315       case OE_Ignore: {
1316         sqlite3VdbeAddOp2(v, OP_IsNull, regNewData+1+i, ignoreDest);
1317         VdbeCoverage(v);
1318         break;
1319       }
1320       default: {
1321         assert( onError==OE_Replace );
1322         addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regNewData+1+i);
1323            VdbeCoverage(v);
1324         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regNewData+1+i);
1325         sqlite3VdbeJumpHere(v, addr1);
1326         break;
1327       }
1328     }
1329   }
1330 
1331   /* Test all CHECK constraints
1332   */
1333 #ifndef SQLITE_OMIT_CHECK
1334   if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
1335     ExprList *pCheck = pTab->pCheck;
1336     pParse->ckBase = regNewData+1;
1337     onError = overrideError!=OE_Default ? overrideError : OE_Abort;
1338     for(i=0; i<pCheck->nExpr; i++){
1339       int allOk;
1340       Expr *pExpr = pCheck->a[i].pExpr;
1341       if( aiChng && checkConstraintUnchanged(pExpr, aiChng, pkChng) ) continue;
1342       allOk = sqlite3VdbeMakeLabel(v);
1343       sqlite3ExprIfTrue(pParse, pExpr, allOk, SQLITE_JUMPIFNULL);
1344       if( onError==OE_Ignore ){
1345         sqlite3VdbeGoto(v, ignoreDest);
1346       }else{
1347         char *zName = pCheck->a[i].zName;
1348         if( zName==0 ) zName = pTab->zName;
1349         if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
1350         sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
1351                               onError, zName, P4_TRANSIENT,
1352                               P5_ConstraintCheck);
1353       }
1354       sqlite3VdbeResolveLabel(v, allOk);
1355     }
1356   }
1357 #endif /* !defined(SQLITE_OMIT_CHECK) */
1358 
1359   /* If rowid is changing, make sure the new rowid does not previously
1360   ** exist in the table.
1361   */
1362   if( pkChng && pPk==0 ){
1363     int addrRowidOk = sqlite3VdbeMakeLabel(v);
1364 
1365     /* Figure out what action to take in case of a rowid collision */
1366     onError = pTab->keyConf;
1367     if( overrideError!=OE_Default ){
1368       onError = overrideError;
1369     }else if( onError==OE_Default ){
1370       onError = OE_Abort;
1371     }
1372 
1373     if( isUpdate ){
1374       /* pkChng!=0 does not mean that the rowid has changed, only that
1375       ** it might have changed.  Skip the conflict logic below if the rowid
1376       ** is unchanged. */
1377       sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
1378       sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
1379       VdbeCoverage(v);
1380     }
1381 
1382     /* If the response to a rowid conflict is REPLACE but the response
1383     ** to some other UNIQUE constraint is FAIL or IGNORE, then we need
1384     ** to defer the running of the rowid conflict checking until after
1385     ** the UNIQUE constraints have run.
1386     */
1387     if( onError==OE_Replace && overrideError!=OE_Replace ){
1388       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
1389         if( pIdx->onError==OE_Ignore || pIdx->onError==OE_Fail ){
1390           ipkTop = sqlite3VdbeAddOp0(v, OP_Goto);
1391           break;
1392         }
1393       }
1394     }
1395 
1396     /* Check to see if the new rowid already exists in the table.  Skip
1397     ** the following conflict logic if it does not. */
1398     sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);
1399     VdbeCoverage(v);
1400 
1401     /* Generate code that deals with a rowid collision */
1402     switch( onError ){
1403       default: {
1404         onError = OE_Abort;
1405         /* Fall thru into the next case */
1406       }
1407       case OE_Rollback:
1408       case OE_Abort:
1409       case OE_Fail: {
1410         sqlite3RowidConstraint(pParse, onError, pTab);
1411         break;
1412       }
1413       case OE_Replace: {
1414         /* If there are DELETE triggers on this table and the
1415         ** recursive-triggers flag is set, call GenerateRowDelete() to
1416         ** remove the conflicting row from the table. This will fire
1417         ** the triggers and remove both the table and index b-tree entries.
1418         **
1419         ** Otherwise, if there are no triggers or the recursive-triggers
1420         ** flag is not set, but the table has one or more indexes, call
1421         ** GenerateRowIndexDelete(). This removes the index b-tree entries
1422         ** only. The table b-tree entry will be replaced by the new entry
1423         ** when it is inserted.
1424         **
1425         ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
1426         ** also invoke MultiWrite() to indicate that this VDBE may require
1427         ** statement rollback (if the statement is aborted after the delete
1428         ** takes place). Earlier versions called sqlite3MultiWrite() regardless,
1429         ** but being more selective here allows statements like:
1430         **
1431         **   REPLACE INTO t(rowid) VALUES($newrowid)
1432         **
1433         ** to run without a statement journal if there are no indexes on the
1434         ** table.
1435         */
1436         Trigger *pTrigger = 0;
1437         if( db->flags&SQLITE_RecTriggers ){
1438           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1439         }
1440         if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
1441           sqlite3MultiWrite(pParse);
1442           sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
1443                                    regNewData, 1, 0, OE_Replace, 1, -1);
1444         }else{
1445 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1446           if( HasRowid(pTab) ){
1447             /* This OP_Delete opcode fires the pre-update-hook only. It does
1448             ** not modify the b-tree. It is more efficient to let the coming
1449             ** OP_Insert replace the existing entry than it is to delete the
1450             ** existing entry and then insert a new one. */
1451             sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
1452             sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
1453           }
1454 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1455           if( pTab->pIndex ){
1456             sqlite3MultiWrite(pParse);
1457             sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
1458           }
1459         }
1460         seenReplace = 1;
1461         break;
1462       }
1463       case OE_Ignore: {
1464         /*assert( seenReplace==0 );*/
1465         sqlite3VdbeGoto(v, ignoreDest);
1466         break;
1467       }
1468     }
1469     sqlite3VdbeResolveLabel(v, addrRowidOk);
1470     if( ipkTop ){
1471       ipkBottom = sqlite3VdbeAddOp0(v, OP_Goto);
1472       sqlite3VdbeJumpHere(v, ipkTop);
1473     }
1474   }
1475 
1476   /* Test all UNIQUE constraints by creating entries for each UNIQUE
1477   ** index and making sure that duplicate entries do not already exist.
1478   ** Compute the revised record entries for indices as we go.
1479   **
1480   ** This loop also handles the case of the PRIMARY KEY index for a
1481   ** WITHOUT ROWID table.
1482   */
1483   for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){
1484     int regIdx;          /* Range of registers hold conent for pIdx */
1485     int regR;            /* Range of registers holding conflicting PK */
1486     int iThisCur;        /* Cursor for this UNIQUE index */
1487     int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */
1488 
1489     if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
1490     if( bAffinityDone==0 ){
1491       sqlite3TableAffinity(v, pTab, regNewData+1);
1492       bAffinityDone = 1;
1493     }
1494     iThisCur = iIdxCur+ix;
1495     addrUniqueOk = sqlite3VdbeMakeLabel(v);
1496 
1497     /* Skip partial indices for which the WHERE clause is not true */
1498     if( pIdx->pPartIdxWhere ){
1499       sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
1500       pParse->ckBase = regNewData+1;
1501       sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
1502                             SQLITE_JUMPIFNULL);
1503       pParse->ckBase = 0;
1504     }
1505 
1506     /* Create a record for this index entry as it should appear after
1507     ** the insert or update.  Store that record in the aRegIdx[ix] register
1508     */
1509     regIdx = aRegIdx[ix]+1;
1510     for(i=0; i<pIdx->nColumn; i++){
1511       int iField = pIdx->aiColumn[i];
1512       int x;
1513       if( iField==XN_EXPR ){
1514         pParse->ckBase = regNewData+1;
1515         sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
1516         pParse->ckBase = 0;
1517         VdbeComment((v, "%s column %d", pIdx->zName, i));
1518       }else{
1519         if( iField==XN_ROWID || iField==pTab->iPKey ){
1520           x = regNewData;
1521         }else{
1522           x = iField + regNewData + 1;
1523         }
1524         sqlite3VdbeAddOp2(v, iField<0 ? OP_IntCopy : OP_SCopy, x, regIdx+i);
1525         VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
1526       }
1527     }
1528     sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
1529     VdbeComment((v, "for %s", pIdx->zName));
1530 
1531     /* In an UPDATE operation, if this index is the PRIMARY KEY index
1532     ** of a WITHOUT ROWID table and there has been no change the
1533     ** primary key, then no collision is possible.  The collision detection
1534     ** logic below can all be skipped. */
1535     if( isUpdate && pPk==pIdx && pkChng==0 ){
1536       sqlite3VdbeResolveLabel(v, addrUniqueOk);
1537       continue;
1538     }
1539 
1540     /* Find out what action to take in case there is a uniqueness conflict */
1541     onError = pIdx->onError;
1542     if( onError==OE_None ){
1543       sqlite3VdbeResolveLabel(v, addrUniqueOk);
1544       continue;  /* pIdx is not a UNIQUE index */
1545     }
1546     if( overrideError!=OE_Default ){
1547       onError = overrideError;
1548     }else if( onError==OE_Default ){
1549       onError = OE_Abort;
1550     }
1551 
1552     /* Collision detection may be omitted if all of the following are true:
1553     **   (1) The conflict resolution algorithm is REPLACE
1554     **   (2) The table is a WITHOUT ROWID table
1555     **   (3) There are no secondary indexes on the table
1556     **   (4) No delete triggers need to be fired if there is a conflict
1557     **   (5) No FK constraint counters need to be updated if a conflict occurs.
1558     */
1559     if( (ix==0 && pIdx->pNext==0)                   /* Condition 3 */
1560      && pPk==pIdx                                   /* Condition 2 */
1561      && onError==OE_Replace                         /* Condition 1 */
1562      && ( 0==(db->flags&SQLITE_RecTriggers) ||      /* Condition 4 */
1563           0==sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0))
1564      && ( 0==(db->flags&SQLITE_ForeignKeys) ||      /* Condition 5 */
1565          (0==pTab->pFKey && 0==sqlite3FkReferences(pTab)))
1566     ){
1567       sqlite3VdbeResolveLabel(v, addrUniqueOk);
1568       continue;
1569     }
1570 
1571     /* Check to see if the new index entry will be unique */
1572     sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
1573                          regIdx, pIdx->nKeyCol); VdbeCoverage(v);
1574 
1575     /* Generate code to handle collisions */
1576     regR = (pIdx==pPk) ? regIdx : sqlite3GetTempRange(pParse, nPkField);
1577     if( isUpdate || onError==OE_Replace ){
1578       if( HasRowid(pTab) ){
1579         sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
1580         /* Conflict only if the rowid of the existing index entry
1581         ** is different from old-rowid */
1582         if( isUpdate ){
1583           sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);
1584           sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
1585           VdbeCoverage(v);
1586         }
1587       }else{
1588         int x;
1589         /* Extract the PRIMARY KEY from the end of the index entry and
1590         ** store it in registers regR..regR+nPk-1 */
1591         if( pIdx!=pPk ){
1592           for(i=0; i<pPk->nKeyCol; i++){
1593             assert( pPk->aiColumn[i]>=0 );
1594             x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
1595             sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
1596             VdbeComment((v, "%s.%s", pTab->zName,
1597                          pTab->aCol[pPk->aiColumn[i]].zName));
1598           }
1599         }
1600         if( isUpdate ){
1601           /* If currently processing the PRIMARY KEY of a WITHOUT ROWID
1602           ** table, only conflict if the new PRIMARY KEY values are actually
1603           ** different from the old.
1604           **
1605           ** For a UNIQUE index, only conflict if the PRIMARY KEY values
1606           ** of the matched index row are different from the original PRIMARY
1607           ** KEY values of this row before the update.  */
1608           int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
1609           int op = OP_Ne;
1610           int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
1611 
1612           for(i=0; i<pPk->nKeyCol; i++){
1613             char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
1614             x = pPk->aiColumn[i];
1615             assert( x>=0 );
1616             if( i==(pPk->nKeyCol-1) ){
1617               addrJump = addrUniqueOk;
1618               op = OP_Eq;
1619             }
1620             sqlite3VdbeAddOp4(v, op,
1621                 regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
1622             );
1623             sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
1624             VdbeCoverageIf(v, op==OP_Eq);
1625             VdbeCoverageIf(v, op==OP_Ne);
1626           }
1627         }
1628       }
1629     }
1630 
1631     /* Generate code that executes if the new index entry is not unique */
1632     assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1633         || onError==OE_Ignore || onError==OE_Replace );
1634     switch( onError ){
1635       case OE_Rollback:
1636       case OE_Abort:
1637       case OE_Fail: {
1638         sqlite3UniqueConstraint(pParse, onError, pIdx);
1639         break;
1640       }
1641       case OE_Ignore: {
1642         sqlite3VdbeGoto(v, ignoreDest);
1643         break;
1644       }
1645       default: {
1646         Trigger *pTrigger = 0;
1647         assert( onError==OE_Replace );
1648         sqlite3MultiWrite(pParse);
1649         if( db->flags&SQLITE_RecTriggers ){
1650           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1651         }
1652         sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
1653             regR, nPkField, 0, OE_Replace,
1654             (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
1655         seenReplace = 1;
1656         break;
1657       }
1658     }
1659     sqlite3VdbeResolveLabel(v, addrUniqueOk);
1660     if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);
1661   }
1662   if( ipkTop ){
1663     sqlite3VdbeGoto(v, ipkTop+1);
1664     sqlite3VdbeJumpHere(v, ipkBottom);
1665   }
1666 
1667   *pbMayReplace = seenReplace;
1668   VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));
1669 }
1670 
1671 /*
1672 ** This routine generates code to finish the INSERT or UPDATE operation
1673 ** that was started by a prior call to sqlite3GenerateConstraintChecks.
1674 ** A consecutive range of registers starting at regNewData contains the
1675 ** rowid and the content to be inserted.
1676 **
1677 ** The arguments to this routine should be the same as the first six
1678 ** arguments to sqlite3GenerateConstraintChecks.
1679 */
1680 void sqlite3CompleteInsertion(
1681   Parse *pParse,      /* The parser context */
1682   Table *pTab,        /* the table into which we are inserting */
1683   int iDataCur,       /* Cursor of the canonical data source */
1684   int iIdxCur,        /* First index cursor */
1685   int regNewData,     /* Range of content */
1686   int *aRegIdx,       /* Register used by each index.  0 for unused indices */
1687   int update_flags,   /* True for UPDATE, False for INSERT */
1688   int appendBias,     /* True if this is likely to be an append */
1689   int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
1690 ){
1691   Vdbe *v;            /* Prepared statements under construction */
1692   Index *pIdx;        /* An index being inserted or updated */
1693   u8 pik_flags;       /* flag values passed to the btree insert */
1694   int regData;        /* Content registers (after the rowid) */
1695   int regRec;         /* Register holding assembled record for the table */
1696   int i;              /* Loop counter */
1697   u8 bAffinityDone = 0; /* True if OP_Affinity has been run already */
1698 
1699   assert( update_flags==0
1700        || update_flags==OPFLAG_ISUPDATE
1701        || update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)
1702   );
1703 
1704   v = sqlite3GetVdbe(pParse);
1705   assert( v!=0 );
1706   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
1707   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
1708     if( aRegIdx[i]==0 ) continue;
1709     bAffinityDone = 1;
1710     if( pIdx->pPartIdxWhere ){
1711       sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
1712       VdbeCoverage(v);
1713     }
1714     sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i],
1715                          aRegIdx[i]+1,
1716                          pIdx->uniqNotNull ? pIdx->nKeyCol: pIdx->nColumn);
1717     pik_flags = 0;
1718     if( useSeekResult ) pik_flags = OPFLAG_USESEEKRESULT;
1719     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
1720       assert( pParse->nested==0 );
1721       pik_flags |= OPFLAG_NCHANGE;
1722       pik_flags |= (update_flags & OPFLAG_SAVEPOSITION);
1723     }
1724     sqlite3VdbeChangeP5(v, pik_flags);
1725   }
1726   if( !HasRowid(pTab) ) return;
1727   regData = regNewData + 1;
1728   regRec = sqlite3GetTempReg(pParse);
1729   sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
1730   if( !bAffinityDone ){
1731     sqlite3TableAffinity(v, pTab, 0);
1732     sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
1733   }
1734   if( pParse->nested ){
1735     pik_flags = 0;
1736   }else{
1737     pik_flags = OPFLAG_NCHANGE;
1738     pik_flags |= (update_flags?update_flags:OPFLAG_LASTROWID);
1739   }
1740   if( appendBias ){
1741     pik_flags |= OPFLAG_APPEND;
1742   }
1743   if( useSeekResult ){
1744     pik_flags |= OPFLAG_USESEEKRESULT;
1745   }
1746   sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, regRec, regNewData);
1747   if( !pParse->nested ){
1748     sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
1749   }
1750   sqlite3VdbeChangeP5(v, pik_flags);
1751 }
1752 
1753 /*
1754 ** Allocate cursors for the pTab table and all its indices and generate
1755 ** code to open and initialized those cursors.
1756 **
1757 ** The cursor for the object that contains the complete data (normally
1758 ** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
1759 ** ROWID table) is returned in *piDataCur.  The first index cursor is
1760 ** returned in *piIdxCur.  The number of indices is returned.
1761 **
1762 ** Use iBase as the first cursor (either the *piDataCur for rowid tables
1763 ** or the first index for WITHOUT ROWID tables) if it is non-negative.
1764 ** If iBase is negative, then allocate the next available cursor.
1765 **
1766 ** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
1767 ** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
1768 ** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
1769 ** pTab->pIndex list.
1770 **
1771 ** If pTab is a virtual table, then this routine is a no-op and the
1772 ** *piDataCur and *piIdxCur values are left uninitialized.
1773 */
1774 int sqlite3OpenTableAndIndices(
1775   Parse *pParse,   /* Parsing context */
1776   Table *pTab,     /* Table to be opened */
1777   int op,          /* OP_OpenRead or OP_OpenWrite */
1778   u8 p5,           /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */
1779   int iBase,       /* Use this for the table cursor, if there is one */
1780   u8 *aToOpen,     /* If not NULL: boolean for each table and index */
1781   int *piDataCur,  /* Write the database source cursor number here */
1782   int *piIdxCur    /* Write the first index cursor number here */
1783 ){
1784   int i;
1785   int iDb;
1786   int iDataCur;
1787   Index *pIdx;
1788   Vdbe *v;
1789 
1790   assert( op==OP_OpenRead || op==OP_OpenWrite );
1791   assert( op==OP_OpenWrite || p5==0 );
1792   if( IsVirtual(pTab) ){
1793     /* This routine is a no-op for virtual tables. Leave the output
1794     ** variables *piDataCur and *piIdxCur uninitialized so that valgrind
1795     ** can detect if they are used by mistake in the caller. */
1796     return 0;
1797   }
1798   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
1799   v = sqlite3GetVdbe(pParse);
1800   assert( v!=0 );
1801   if( iBase<0 ) iBase = pParse->nTab;
1802   iDataCur = iBase++;
1803   if( piDataCur ) *piDataCur = iDataCur;
1804   if( HasRowid(pTab) && (aToOpen==0 || aToOpen[0]) ){
1805     sqlite3OpenTable(pParse, iDataCur, iDb, pTab, op);
1806   }else{
1807     sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
1808   }
1809   if( piIdxCur ) *piIdxCur = iBase;
1810   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
1811     int iIdxCur = iBase++;
1812     assert( pIdx->pSchema==pTab->pSchema );
1813     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
1814       if( piDataCur ) *piDataCur = iIdxCur;
1815       p5 = 0;
1816     }
1817     if( aToOpen==0 || aToOpen[i+1] ){
1818       sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
1819       sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
1820       sqlite3VdbeChangeP5(v, p5);
1821       VdbeComment((v, "%s", pIdx->zName));
1822     }
1823   }
1824   if( iBase>pParse->nTab ) pParse->nTab = iBase;
1825   return i;
1826 }
1827 
1828 
1829 #ifdef SQLITE_TEST
1830 /*
1831 ** The following global variable is incremented whenever the
1832 ** transfer optimization is used.  This is used for testing
1833 ** purposes only - to make sure the transfer optimization really
1834 ** is happening when it is supposed to.
1835 */
1836 int sqlite3_xferopt_count;
1837 #endif /* SQLITE_TEST */
1838 
1839 
1840 #ifndef SQLITE_OMIT_XFER_OPT
1841 /*
1842 ** Check to see if index pSrc is compatible as a source of data
1843 ** for index pDest in an insert transfer optimization.  The rules
1844 ** for a compatible index:
1845 **
1846 **    *   The index is over the same set of columns
1847 **    *   The same DESC and ASC markings occurs on all columns
1848 **    *   The same onError processing (OE_Abort, OE_Ignore, etc)
1849 **    *   The same collating sequence on each column
1850 **    *   The index has the exact same WHERE clause
1851 */
1852 static int xferCompatibleIndex(Index *pDest, Index *pSrc){
1853   int i;
1854   assert( pDest && pSrc );
1855   assert( pDest->pTable!=pSrc->pTable );
1856   if( pDest->nKeyCol!=pSrc->nKeyCol ){
1857     return 0;   /* Different number of columns */
1858   }
1859   if( pDest->onError!=pSrc->onError ){
1860     return 0;   /* Different conflict resolution strategies */
1861   }
1862   for(i=0; i<pSrc->nKeyCol; i++){
1863     if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
1864       return 0;   /* Different columns indexed */
1865     }
1866     if( pSrc->aiColumn[i]==XN_EXPR ){
1867       assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
1868       if( sqlite3ExprCompare(pSrc->aColExpr->a[i].pExpr,
1869                              pDest->aColExpr->a[i].pExpr, -1)!=0 ){
1870         return 0;   /* Different expressions in the index */
1871       }
1872     }
1873     if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
1874       return 0;   /* Different sort orders */
1875     }
1876     if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){
1877       return 0;   /* Different collating sequences */
1878     }
1879   }
1880   if( sqlite3ExprCompare(pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
1881     return 0;     /* Different WHERE clauses */
1882   }
1883 
1884   /* If no test above fails then the indices must be compatible */
1885   return 1;
1886 }
1887 
1888 /*
1889 ** Attempt the transfer optimization on INSERTs of the form
1890 **
1891 **     INSERT INTO tab1 SELECT * FROM tab2;
1892 **
1893 ** The xfer optimization transfers raw records from tab2 over to tab1.
1894 ** Columns are not decoded and reassembled, which greatly improves
1895 ** performance.  Raw index records are transferred in the same way.
1896 **
1897 ** The xfer optimization is only attempted if tab1 and tab2 are compatible.
1898 ** There are lots of rules for determining compatibility - see comments
1899 ** embedded in the code for details.
1900 **
1901 ** This routine returns TRUE if the optimization is guaranteed to be used.
1902 ** Sometimes the xfer optimization will only work if the destination table
1903 ** is empty - a factor that can only be determined at run-time.  In that
1904 ** case, this routine generates code for the xfer optimization but also
1905 ** does a test to see if the destination table is empty and jumps over the
1906 ** xfer optimization code if the test fails.  In that case, this routine
1907 ** returns FALSE so that the caller will know to go ahead and generate
1908 ** an unoptimized transfer.  This routine also returns FALSE if there
1909 ** is no chance that the xfer optimization can be applied.
1910 **
1911 ** This optimization is particularly useful at making VACUUM run faster.
1912 */
1913 static int xferOptimization(
1914   Parse *pParse,        /* Parser context */
1915   Table *pDest,         /* The table we are inserting into */
1916   Select *pSelect,      /* A SELECT statement to use as the data source */
1917   int onError,          /* How to handle constraint errors */
1918   int iDbDest           /* The database of pDest */
1919 ){
1920   sqlite3 *db = pParse->db;
1921   ExprList *pEList;                /* The result set of the SELECT */
1922   Table *pSrc;                     /* The table in the FROM clause of SELECT */
1923   Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
1924   struct SrcList_item *pItem;      /* An element of pSelect->pSrc */
1925   int i;                           /* Loop counter */
1926   int iDbSrc;                      /* The database of pSrc */
1927   int iSrc, iDest;                 /* Cursors from source and destination */
1928   int addr1, addr2;                /* Loop addresses */
1929   int emptyDestTest = 0;           /* Address of test for empty pDest */
1930   int emptySrcTest = 0;            /* Address of test for empty pSrc */
1931   Vdbe *v;                         /* The VDBE we are building */
1932   int regAutoinc;                  /* Memory register used by AUTOINC */
1933   int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
1934   int regData, regRowid;           /* Registers holding data and rowid */
1935 
1936   if( pSelect==0 ){
1937     return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
1938   }
1939   if( pParse->pWith || pSelect->pWith ){
1940     /* Do not attempt to process this query if there are an WITH clauses
1941     ** attached to it. Proceeding may generate a false "no such table: xxx"
1942     ** error if pSelect reads from a CTE named "xxx".  */
1943     return 0;
1944   }
1945   if( sqlite3TriggerList(pParse, pDest) ){
1946     return 0;   /* tab1 must not have triggers */
1947   }
1948 #ifndef SQLITE_OMIT_VIRTUALTABLE
1949   if( pDest->tabFlags & TF_Virtual ){
1950     return 0;   /* tab1 must not be a virtual table */
1951   }
1952 #endif
1953   if( onError==OE_Default ){
1954     if( pDest->iPKey>=0 ) onError = pDest->keyConf;
1955     if( onError==OE_Default ) onError = OE_Abort;
1956   }
1957   assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
1958   if( pSelect->pSrc->nSrc!=1 ){
1959     return 0;   /* FROM clause must have exactly one term */
1960   }
1961   if( pSelect->pSrc->a[0].pSelect ){
1962     return 0;   /* FROM clause cannot contain a subquery */
1963   }
1964   if( pSelect->pWhere ){
1965     return 0;   /* SELECT may not have a WHERE clause */
1966   }
1967   if( pSelect->pOrderBy ){
1968     return 0;   /* SELECT may not have an ORDER BY clause */
1969   }
1970   /* Do not need to test for a HAVING clause.  If HAVING is present but
1971   ** there is no ORDER BY, we will get an error. */
1972   if( pSelect->pGroupBy ){
1973     return 0;   /* SELECT may not have a GROUP BY clause */
1974   }
1975   if( pSelect->pLimit ){
1976     return 0;   /* SELECT may not have a LIMIT clause */
1977   }
1978   assert( pSelect->pOffset==0 );  /* Must be so if pLimit==0 */
1979   if( pSelect->pPrior ){
1980     return 0;   /* SELECT may not be a compound query */
1981   }
1982   if( pSelect->selFlags & SF_Distinct ){
1983     return 0;   /* SELECT may not be DISTINCT */
1984   }
1985   pEList = pSelect->pEList;
1986   assert( pEList!=0 );
1987   if( pEList->nExpr!=1 ){
1988     return 0;   /* The result set must have exactly one column */
1989   }
1990   assert( pEList->a[0].pExpr );
1991   if( pEList->a[0].pExpr->op!=TK_ASTERISK ){
1992     return 0;   /* The result set must be the special operator "*" */
1993   }
1994 
1995   /* At this point we have established that the statement is of the
1996   ** correct syntactic form to participate in this optimization.  Now
1997   ** we have to check the semantics.
1998   */
1999   pItem = pSelect->pSrc->a;
2000   pSrc = sqlite3LocateTableItem(pParse, 0, pItem);
2001   if( pSrc==0 ){
2002     return 0;   /* FROM clause does not contain a real table */
2003   }
2004   if( pSrc==pDest ){
2005     return 0;   /* tab1 and tab2 may not be the same table */
2006   }
2007   if( HasRowid(pDest)!=HasRowid(pSrc) ){
2008     return 0;   /* source and destination must both be WITHOUT ROWID or not */
2009   }
2010 #ifndef SQLITE_OMIT_VIRTUALTABLE
2011   if( pSrc->tabFlags & TF_Virtual ){
2012     return 0;   /* tab2 must not be a virtual table */
2013   }
2014 #endif
2015   if( pSrc->pSelect ){
2016     return 0;   /* tab2 may not be a view */
2017   }
2018   if( pDest->nCol!=pSrc->nCol ){
2019     return 0;   /* Number of columns must be the same in tab1 and tab2 */
2020   }
2021   if( pDest->iPKey!=pSrc->iPKey ){
2022     return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
2023   }
2024   for(i=0; i<pDest->nCol; i++){
2025     Column *pDestCol = &pDest->aCol[i];
2026     Column *pSrcCol = &pSrc->aCol[i];
2027 #ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
2028     if( (db->flags & SQLITE_Vacuum)==0
2029      && (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN
2030     ){
2031       return 0;    /* Neither table may have __hidden__ columns */
2032     }
2033 #endif
2034     if( pDestCol->affinity!=pSrcCol->affinity ){
2035       return 0;    /* Affinity must be the same on all columns */
2036     }
2037     if( sqlite3_stricmp(pDestCol->zColl, pSrcCol->zColl)!=0 ){
2038       return 0;    /* Collating sequence must be the same on all columns */
2039     }
2040     if( pDestCol->notNull && !pSrcCol->notNull ){
2041       return 0;    /* tab2 must be NOT NULL if tab1 is */
2042     }
2043     /* Default values for second and subsequent columns need to match. */
2044     if( i>0 ){
2045       assert( pDestCol->pDflt==0 || pDestCol->pDflt->op==TK_SPAN );
2046       assert( pSrcCol->pDflt==0 || pSrcCol->pDflt->op==TK_SPAN );
2047       if( (pDestCol->pDflt==0)!=(pSrcCol->pDflt==0)
2048        || (pDestCol->pDflt && strcmp(pDestCol->pDflt->u.zToken,
2049                                        pSrcCol->pDflt->u.zToken)!=0)
2050       ){
2051         return 0;    /* Default values must be the same for all columns */
2052       }
2053     }
2054   }
2055   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
2056     if( IsUniqueIndex(pDestIdx) ){
2057       destHasUniqueIdx = 1;
2058     }
2059     for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
2060       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
2061     }
2062     if( pSrcIdx==0 ){
2063       return 0;    /* pDestIdx has no corresponding index in pSrc */
2064     }
2065   }
2066 #ifndef SQLITE_OMIT_CHECK
2067   if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){
2068     return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
2069   }
2070 #endif
2071 #ifndef SQLITE_OMIT_FOREIGN_KEY
2072   /* Disallow the transfer optimization if the destination table constains
2073   ** any foreign key constraints.  This is more restrictive than necessary.
2074   ** But the main beneficiary of the transfer optimization is the VACUUM
2075   ** command, and the VACUUM command disables foreign key constraints.  So
2076   ** the extra complication to make this rule less restrictive is probably
2077   ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
2078   */
2079   if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
2080     return 0;
2081   }
2082 #endif
2083   if( (db->flags & SQLITE_CountRows)!=0 ){
2084     return 0;  /* xfer opt does not play well with PRAGMA count_changes */
2085   }
2086 
2087   /* If we get this far, it means that the xfer optimization is at
2088   ** least a possibility, though it might only work if the destination
2089   ** table (tab1) is initially empty.
2090   */
2091 #ifdef SQLITE_TEST
2092   sqlite3_xferopt_count++;
2093 #endif
2094   iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);
2095   v = sqlite3GetVdbe(pParse);
2096   sqlite3CodeVerifySchema(pParse, iDbSrc);
2097   iSrc = pParse->nTab++;
2098   iDest = pParse->nTab++;
2099   regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
2100   regData = sqlite3GetTempReg(pParse);
2101   regRowid = sqlite3GetTempReg(pParse);
2102   sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
2103   assert( HasRowid(pDest) || destHasUniqueIdx );
2104   if( (db->flags & SQLITE_Vacuum)==0 && (
2105       (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
2106    || destHasUniqueIdx                              /* (2) */
2107    || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */
2108   )){
2109     /* In some circumstances, we are able to run the xfer optimization
2110     ** only if the destination table is initially empty. Unless the
2111     ** SQLITE_Vacuum flag is set, this block generates code to make
2112     ** that determination. If SQLITE_Vacuum is set, then the destination
2113     ** table is always empty.
2114     **
2115     ** Conditions under which the destination must be empty:
2116     **
2117     ** (1) There is no INTEGER PRIMARY KEY but there are indices.
2118     **     (If the destination is not initially empty, the rowid fields
2119     **     of index entries might need to change.)
2120     **
2121     ** (2) The destination has a unique index.  (The xfer optimization
2122     **     is unable to test uniqueness.)
2123     **
2124     ** (3) onError is something other than OE_Abort and OE_Rollback.
2125     */
2126     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);
2127     emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);
2128     sqlite3VdbeJumpHere(v, addr1);
2129   }
2130   if( HasRowid(pSrc) ){
2131     u8 insFlags;
2132     sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
2133     emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
2134     if( pDest->iPKey>=0 ){
2135       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
2136       addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
2137       VdbeCoverage(v);
2138       sqlite3RowidConstraint(pParse, onError, pDest);
2139       sqlite3VdbeJumpHere(v, addr2);
2140       autoIncStep(pParse, regAutoinc, regRowid);
2141     }else if( pDest->pIndex==0 ){
2142       addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
2143     }else{
2144       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
2145       assert( (pDest->tabFlags & TF_Autoincrement)==0 );
2146     }
2147     sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
2148     if( db->flags & SQLITE_Vacuum ){
2149       sqlite3VdbeAddOp3(v, OP_Last, iDest, 0, -1);
2150       insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|
2151                            OPFLAG_APPEND|OPFLAG_USESEEKRESULT;
2152     }else{
2153       insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;
2154     }
2155     sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
2156                       (char*)pDest, P4_TABLE);
2157     sqlite3VdbeChangeP5(v, insFlags);
2158     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
2159     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
2160     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
2161   }else{
2162     sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);
2163     sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
2164   }
2165   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
2166     u8 idxInsFlags = 0;
2167     for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
2168       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
2169     }
2170     assert( pSrcIdx );
2171     sqlite3VdbeAddOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc);
2172     sqlite3VdbeSetP4KeyInfo(pParse, pSrcIdx);
2173     VdbeComment((v, "%s", pSrcIdx->zName));
2174     sqlite3VdbeAddOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest);
2175     sqlite3VdbeSetP4KeyInfo(pParse, pDestIdx);
2176     sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
2177     VdbeComment((v, "%s", pDestIdx->zName));
2178     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
2179     sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
2180     if( db->flags & SQLITE_Vacuum ){
2181       /* This INSERT command is part of a VACUUM operation, which guarantees
2182       ** that the destination table is empty. If all indexed columns use
2183       ** collation sequence BINARY, then it can also be assumed that the
2184       ** index will be populated by inserting keys in strictly sorted
2185       ** order. In this case, instead of seeking within the b-tree as part
2186       ** of every OP_IdxInsert opcode, an OP_Last is added before the
2187       ** OP_IdxInsert to seek to the point within the b-tree where each key
2188       ** should be inserted. This is faster.
2189       **
2190       ** If any of the indexed columns use a collation sequence other than
2191       ** BINARY, this optimization is disabled. This is because the user
2192       ** might change the definition of a collation sequence and then run
2193       ** a VACUUM command. In that case keys may not be written in strictly
2194       ** sorted order.  */
2195       for(i=0; i<pSrcIdx->nColumn; i++){
2196         const char *zColl = pSrcIdx->azColl[i];
2197         assert( sqlite3_stricmp(sqlite3StrBINARY, zColl)!=0
2198                     || sqlite3StrBINARY==zColl );
2199         if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
2200       }
2201       if( i==pSrcIdx->nColumn ){
2202         idxInsFlags = OPFLAG_USESEEKRESULT;
2203         sqlite3VdbeAddOp3(v, OP_Last, iDest, 0, -1);
2204       }
2205     }
2206     if( !HasRowid(pSrc) && pDestIdx->idxType==2 ){
2207       idxInsFlags |= OPFLAG_NCHANGE;
2208     }
2209     sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
2210     sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);
2211     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
2212     sqlite3VdbeJumpHere(v, addr1);
2213     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
2214     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
2215   }
2216   if( emptySrcTest ) sqlite3VdbeJumpHere(v, emptySrcTest);
2217   sqlite3ReleaseTempReg(pParse, regRowid);
2218   sqlite3ReleaseTempReg(pParse, regData);
2219   if( emptyDestTest ){
2220     sqlite3AutoincrementEnd(pParse);
2221     sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
2222     sqlite3VdbeJumpHere(v, emptyDestTest);
2223     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
2224     return 0;
2225   }else{
2226     return 1;
2227   }
2228 }
2229 #endif /* SQLITE_OMIT_XFER_OPT */
2230