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 open a table for reading.
19*/
20void sqlite3OpenTable(
21  Parse *p,       /* Generate code into this VDBE */
22  int iCur,       /* The cursor number of the table */
23  int iDb,        /* The database index in sqlite3.aDb[] */
24  Table *pTab,    /* The table to be opened */
25  int opcode      /* OP_OpenRead or OP_OpenWrite */
26){
27  Vdbe *v;
28  if( IsVirtual(pTab) ) return;
29  v = sqlite3GetVdbe(p);
30  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
31  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite)?1:0, pTab->zName);
32  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
33  sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(pTab->nCol), P4_INT32);
34  VdbeComment((v, "%s", pTab->zName));
35}
36
37/*
38** Return a pointer to the column affinity string associated with index
39** pIdx. A column affinity string has one character for each column in
40** the table, according to the affinity of the column:
41**
42**  Character      Column affinity
43**  ------------------------------
44**  'a'            TEXT
45**  'b'            NONE
46**  'c'            NUMERIC
47**  'd'            INTEGER
48**  'e'            REAL
49**
50** An extra 'b' is appended to the end of the string to cover the
51** rowid that appears as the last column in every index.
52**
53** Memory for the buffer containing the column index affinity string
54** is managed along with the rest of the Index structure. It will be
55** released when sqlite3DeleteIndex() is called.
56*/
57const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
58  if( !pIdx->zColAff ){
59    /* The first time a column affinity string for a particular index is
60    ** required, it is allocated and populated here. It is then stored as
61    ** a member of the Index structure for subsequent use.
62    **
63    ** The column affinity string will eventually be deleted by
64    ** sqliteDeleteIndex() when the Index structure itself is cleaned
65    ** up.
66    */
67    int n;
68    Table *pTab = pIdx->pTable;
69    sqlite3 *db = sqlite3VdbeDb(v);
70    pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+2);
71    if( !pIdx->zColAff ){
72      db->mallocFailed = 1;
73      return 0;
74    }
75    for(n=0; n<pIdx->nColumn; n++){
76      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
77    }
78    pIdx->zColAff[n++] = SQLITE_AFF_NONE;
79    pIdx->zColAff[n] = 0;
80  }
81
82  return pIdx->zColAff;
83}
84
85/*
86** Set P4 of the most recently inserted opcode to a column affinity
87** string for table pTab. A column affinity string has one character
88** for each column indexed by the index, according to the affinity of the
89** column:
90**
91**  Character      Column affinity
92**  ------------------------------
93**  'a'            TEXT
94**  'b'            NONE
95**  'c'            NUMERIC
96**  'd'            INTEGER
97**  'e'            REAL
98*/
99void sqlite3TableAffinityStr(Vdbe *v, Table *pTab){
100  /* The first time a column affinity string for a particular table
101  ** is required, it is allocated and populated here. It is then
102  ** stored as a member of the Table structure for subsequent use.
103  **
104  ** The column affinity string will eventually be deleted by
105  ** sqlite3DeleteTable() when the Table structure itself is cleaned up.
106  */
107  if( !pTab->zColAff ){
108    char *zColAff;
109    int i;
110    sqlite3 *db = sqlite3VdbeDb(v);
111
112    zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
113    if( !zColAff ){
114      db->mallocFailed = 1;
115      return;
116    }
117
118    for(i=0; i<pTab->nCol; i++){
119      zColAff[i] = pTab->aCol[i].affinity;
120    }
121    zColAff[pTab->nCol] = '\0';
122
123    pTab->zColAff = zColAff;
124  }
125
126  sqlite3VdbeChangeP4(v, -1, pTab->zColAff, P4_TRANSIENT);
127}
128
129/*
130** Return non-zero if the table pTab in database iDb or any of its indices
131** have been opened at any point in the VDBE program beginning at location
132** iStartAddr throught the end of the program.  This is used to see if
133** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can
134** run without using temporary table for the results of the SELECT.
135*/
136static int readsTable(Parse *p, int iStartAddr, int iDb, Table *pTab){
137  Vdbe *v = sqlite3GetVdbe(p);
138  int i;
139  int iEnd = sqlite3VdbeCurrentAddr(v);
140#ifndef SQLITE_OMIT_VIRTUALTABLE
141  VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
142#endif
143
144  for(i=iStartAddr; i<iEnd; i++){
145    VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
146    assert( pOp!=0 );
147    if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
148      Index *pIndex;
149      int tnum = pOp->p2;
150      if( tnum==pTab->tnum ){
151        return 1;
152      }
153      for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
154        if( tnum==pIndex->tnum ){
155          return 1;
156        }
157      }
158    }
159#ifndef SQLITE_OMIT_VIRTUALTABLE
160    if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){
161      assert( pOp->p4.pVtab!=0 );
162      assert( pOp->p4type==P4_VTAB );
163      return 1;
164    }
165#endif
166  }
167  return 0;
168}
169
170#ifndef SQLITE_OMIT_AUTOINCREMENT
171/*
172** Locate or create an AutoincInfo structure associated with table pTab
173** which is in database iDb.  Return the register number for the register
174** that holds the maximum rowid.
175**
176** There is at most one AutoincInfo structure per table even if the
177** same table is autoincremented multiple times due to inserts within
178** triggers.  A new AutoincInfo structure is created if this is the
179** first use of table pTab.  On 2nd and subsequent uses, the original
180** AutoincInfo structure is used.
181**
182** Three memory locations are allocated:
183**
184**   (1)  Register to hold the name of the pTab table.
185**   (2)  Register to hold the maximum ROWID of pTab.
186**   (3)  Register to hold the rowid in sqlite_sequence of pTab
187**
188** The 2nd register is the one that is returned.  That is all the
189** insert routine needs to know about.
190*/
191static int autoIncBegin(
192  Parse *pParse,      /* Parsing context */
193  int iDb,            /* Index of the database holding pTab */
194  Table *pTab         /* The table we are writing to */
195){
196  int memId = 0;      /* Register holding maximum rowid */
197  if( pTab->tabFlags & TF_Autoincrement ){
198    Parse *pToplevel = sqlite3ParseToplevel(pParse);
199    AutoincInfo *pInfo;
200
201    pInfo = pToplevel->pAinc;
202    while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
203    if( pInfo==0 ){
204      pInfo = sqlite3DbMallocRaw(pParse->db, sizeof(*pInfo));
205      if( pInfo==0 ) return 0;
206      pInfo->pNext = pToplevel->pAinc;
207      pToplevel->pAinc = pInfo;
208      pInfo->pTab = pTab;
209      pInfo->iDb = iDb;
210      pToplevel->nMem++;                  /* Register to hold name of table */
211      pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */
212      pToplevel->nMem++;                  /* Rowid in sqlite_sequence */
213    }
214    memId = pInfo->regCtr;
215  }
216  return memId;
217}
218
219/*
220** This routine generates code that will initialize all of the
221** register used by the autoincrement tracker.
222*/
223void sqlite3AutoincrementBegin(Parse *pParse){
224  AutoincInfo *p;            /* Information about an AUTOINCREMENT */
225  sqlite3 *db = pParse->db;  /* The database connection */
226  Db *pDb;                   /* Database only autoinc table */
227  int memId;                 /* Register holding max rowid */
228  int addr;                  /* A VDBE address */
229  Vdbe *v = pParse->pVdbe;   /* VDBE under construction */
230
231  /* This routine is never called during trigger-generation.  It is
232  ** only called from the top-level */
233  assert( pParse->pTriggerTab==0 );
234  assert( pParse==sqlite3ParseToplevel(pParse) );
235
236  assert( v );   /* We failed long ago if this is not so */
237  for(p = pParse->pAinc; p; p = p->pNext){
238    pDb = &db->aDb[p->iDb];
239    memId = p->regCtr;
240    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
241    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
242    addr = sqlite3VdbeCurrentAddr(v);
243    sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, p->pTab->zName, 0);
244    sqlite3VdbeAddOp2(v, OP_Rewind, 0, addr+9);
245    sqlite3VdbeAddOp3(v, OP_Column, 0, 0, memId);
246    sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId);
247    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
248    sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
249    sqlite3VdbeAddOp3(v, OP_Column, 0, 1, memId);
250    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+9);
251    sqlite3VdbeAddOp2(v, OP_Next, 0, addr+2);
252    sqlite3VdbeAddOp2(v, OP_Integer, 0, memId);
253    sqlite3VdbeAddOp0(v, OP_Close);
254  }
255}
256
257/*
258** Update the maximum rowid for an autoincrement calculation.
259**
260** This routine should be called when the top of the stack holds a
261** new rowid that is about to be inserted.  If that new rowid is
262** larger than the maximum rowid in the memId memory cell, then the
263** memory cell is updated.  The stack is unchanged.
264*/
265static void autoIncStep(Parse *pParse, int memId, int regRowid){
266  if( memId>0 ){
267    sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
268  }
269}
270
271/*
272** This routine generates the code needed to write autoincrement
273** maximum rowid values back into the sqlite_sequence register.
274** Every statement that might do an INSERT into an autoincrement
275** table (either directly or through triggers) needs to call this
276** routine just before the "exit" code.
277*/
278void sqlite3AutoincrementEnd(Parse *pParse){
279  AutoincInfo *p;
280  Vdbe *v = pParse->pVdbe;
281  sqlite3 *db = pParse->db;
282
283  assert( v );
284  for(p = pParse->pAinc; p; p = p->pNext){
285    Db *pDb = &db->aDb[p->iDb];
286    int j1, j2, j3, j4, j5;
287    int iRec;
288    int memId = p->regCtr;
289
290    iRec = sqlite3GetTempReg(pParse);
291    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
292    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
293    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1);
294    j2 = sqlite3VdbeAddOp0(v, OP_Rewind);
295    j3 = sqlite3VdbeAddOp3(v, OP_Column, 0, 0, iRec);
296    j4 = sqlite3VdbeAddOp3(v, OP_Eq, memId-1, 0, iRec);
297    sqlite3VdbeAddOp2(v, OP_Next, 0, j3);
298    sqlite3VdbeJumpHere(v, j2);
299    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, memId+1);
300    j5 = sqlite3VdbeAddOp0(v, OP_Goto);
301    sqlite3VdbeJumpHere(v, j4);
302    sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
303    sqlite3VdbeJumpHere(v, j1);
304    sqlite3VdbeJumpHere(v, j5);
305    sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, iRec);
306    sqlite3VdbeAddOp3(v, OP_Insert, 0, iRec, memId+1);
307    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
308    sqlite3VdbeAddOp0(v, OP_Close);
309    sqlite3ReleaseTempReg(pParse, iRec);
310  }
311}
312#else
313/*
314** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
315** above are all no-ops
316*/
317# define autoIncBegin(A,B,C) (0)
318# define autoIncStep(A,B,C)
319#endif /* SQLITE_OMIT_AUTOINCREMENT */
320
321
322/* Forward declaration */
323static int xferOptimization(
324  Parse *pParse,        /* Parser context */
325  Table *pDest,         /* The table we are inserting into */
326  Select *pSelect,      /* A SELECT statement to use as the data source */
327  int onError,          /* How to handle constraint errors */
328  int iDbDest           /* The database of pDest */
329);
330
331/*
332** This routine is call to handle SQL of the following forms:
333**
334**    insert into TABLE (IDLIST) values(EXPRLIST)
335**    insert into TABLE (IDLIST) select
336**
337** The IDLIST following the table name is always optional.  If omitted,
338** then a list of all columns for the table is substituted.  The IDLIST
339** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
340**
341** The pList parameter holds EXPRLIST in the first form of the INSERT
342** statement above, and pSelect is NULL.  For the second form, pList is
343** NULL and pSelect is a pointer to the select statement used to generate
344** data for the insert.
345**
346** The code generated follows one of four templates.  For a simple
347** select with data coming from a VALUES clause, the code executes
348** once straight down through.  Pseudo-code follows (we call this
349** the "1st template"):
350**
351**         open write cursor to <table> and its indices
352**         puts VALUES clause expressions onto the stack
353**         write the resulting record into <table>
354**         cleanup
355**
356** The three remaining templates assume the statement is of the form
357**
358**   INSERT INTO <table> SELECT ...
359**
360** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
361** in other words if the SELECT pulls all columns from a single table
362** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
363** if <table2> and <table1> are distinct tables but have identical
364** schemas, including all the same indices, then a special optimization
365** is invoked that copies raw records from <table2> over to <table1>.
366** See the xferOptimization() function for the implementation of this
367** template.  This is the 2nd template.
368**
369**         open a write cursor to <table>
370**         open read cursor on <table2>
371**         transfer all records in <table2> over to <table>
372**         close cursors
373**         foreach index on <table>
374**           open a write cursor on the <table> index
375**           open a read cursor on the corresponding <table2> index
376**           transfer all records from the read to the write cursors
377**           close cursors
378**         end foreach
379**
380** The 3rd template is for when the second template does not apply
381** and the SELECT clause does not read from <table> at any time.
382** The generated code follows this template:
383**
384**         EOF <- 0
385**         X <- A
386**         goto B
387**      A: setup for the SELECT
388**         loop over the rows in the SELECT
389**           load values into registers R..R+n
390**           yield X
391**         end loop
392**         cleanup after the SELECT
393**         EOF <- 1
394**         yield X
395**         goto A
396**      B: open write cursor to <table> and its indices
397**      C: yield X
398**         if EOF goto D
399**         insert the select result into <table> from R..R+n
400**         goto C
401**      D: cleanup
402**
403** The 4th template is used if the insert statement takes its
404** values from a SELECT but the data is being inserted into a table
405** that is also read as part of the SELECT.  In the third form,
406** we have to use a intermediate table to store the results of
407** the select.  The template is like this:
408**
409**         EOF <- 0
410**         X <- A
411**         goto B
412**      A: setup for the SELECT
413**         loop over the tables in the SELECT
414**           load value into register R..R+n
415**           yield X
416**         end loop
417**         cleanup after the SELECT
418**         EOF <- 1
419**         yield X
420**         halt-error
421**      B: open temp table
422**      L: yield X
423**         if EOF goto M
424**         insert row from R..R+n into temp table
425**         goto L
426**      M: open write cursor to <table> and its indices
427**         rewind temp table
428**      C: loop over rows of intermediate table
429**           transfer values form intermediate table into <table>
430**         end loop
431**      D: cleanup
432*/
433void sqlite3Insert(
434  Parse *pParse,        /* Parser context */
435  SrcList *pTabList,    /* Name of table into which we are inserting */
436  ExprList *pList,      /* List of values to be inserted */
437  Select *pSelect,      /* A SELECT statement to use as the data source */
438  IdList *pColumn,      /* Column names corresponding to IDLIST. */
439  int onError           /* How to handle constraint errors */
440){
441  sqlite3 *db;          /* The main database structure */
442  Table *pTab;          /* The table to insert into.  aka TABLE */
443  char *zTab;           /* Name of the table into which we are inserting */
444  const char *zDb;      /* Name of the database holding this table */
445  int i, j, idx;        /* Loop counters */
446  Vdbe *v;              /* Generate code into this virtual machine */
447  Index *pIdx;          /* For looping over indices of the table */
448  int nColumn;          /* Number of columns in the data */
449  int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */
450  int baseCur = 0;      /* VDBE Cursor number for pTab */
451  int keyColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
452  int endOfLoop;        /* Label for the end of the insertion loop */
453  int useTempTable = 0; /* Store SELECT results in intermediate table */
454  int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
455  int addrInsTop = 0;   /* Jump to label "D" */
456  int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
457  int addrSelect = 0;   /* Address of coroutine that implements the SELECT */
458  SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
459  int iDb;              /* Index of database holding TABLE */
460  Db *pDb;              /* The database containing table being inserted into */
461  int appendFlag = 0;   /* True if the insert is likely to be an append */
462
463  /* Register allocations */
464  int regFromSelect = 0;/* Base register for data coming from SELECT */
465  int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
466  int regRowCount = 0;  /* Memory cell used for the row counter */
467  int regIns;           /* Block of regs holding rowid+data being inserted */
468  int regRowid;         /* registers holding insert rowid */
469  int regData;          /* register holding first column to insert */
470  int regEof = 0;       /* Register recording end of SELECT data */
471  int *aRegIdx = 0;     /* One register allocated to each index */
472
473#ifndef SQLITE_OMIT_TRIGGER
474  int isView;                 /* True if attempting to insert into a view */
475  Trigger *pTrigger;          /* List of triggers on pTab, if required */
476  int tmask;                  /* Mask of trigger times */
477#endif
478
479  db = pParse->db;
480  memset(&dest, 0, sizeof(dest));
481  if( pParse->nErr || db->mallocFailed ){
482    goto insert_cleanup;
483  }
484
485  /* Locate the table into which we will be inserting new information.
486  */
487  assert( pTabList->nSrc==1 );
488  zTab = pTabList->a[0].zName;
489  if( NEVER(zTab==0) ) goto insert_cleanup;
490  pTab = sqlite3SrcListLookup(pParse, pTabList);
491  if( pTab==0 ){
492    goto insert_cleanup;
493  }
494  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
495  assert( iDb<db->nDb );
496  pDb = &db->aDb[iDb];
497  zDb = pDb->zName;
498  if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
499    goto insert_cleanup;
500  }
501
502  /* Figure out if we have any triggers and if the table being
503  ** inserted into is a view
504  */
505#ifndef SQLITE_OMIT_TRIGGER
506  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
507  isView = pTab->pSelect!=0;
508#else
509# define pTrigger 0
510# define tmask 0
511# define isView 0
512#endif
513#ifdef SQLITE_OMIT_VIEW
514# undef isView
515# define isView 0
516#endif
517  assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );
518
519  /* If pTab is really a view, make sure it has been initialized.
520  ** ViewGetColumnNames() is a no-op if pTab is not a view (or virtual
521  ** module table).
522  */
523  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
524    goto insert_cleanup;
525  }
526
527  /* Ensure that:
528  *  (a) the table is not read-only,
529  *  (b) that if it is a view then ON INSERT triggers exist
530  */
531  if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
532    goto insert_cleanup;
533  }
534
535  /* Allocate a VDBE
536  */
537  v = sqlite3GetVdbe(pParse);
538  if( v==0 ) goto insert_cleanup;
539  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
540  sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);
541
542#ifndef SQLITE_OMIT_XFER_OPT
543  /* If the statement is of the form
544  **
545  **       INSERT INTO <table1> SELECT * FROM <table2>;
546  **
547  ** Then special optimizations can be applied that make the transfer
548  ** very fast and which reduce fragmentation of indices.
549  **
550  ** This is the 2nd template.
551  */
552  if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
553    assert( !pTrigger );
554    assert( pList==0 );
555    goto insert_end;
556  }
557#endif /* SQLITE_OMIT_XFER_OPT */
558
559  /* If this is an AUTOINCREMENT table, look up the sequence number in the
560  ** sqlite_sequence table and store it in memory cell regAutoinc.
561  */
562  regAutoinc = autoIncBegin(pParse, iDb, pTab);
563
564  /* Figure out how many columns of data are supplied.  If the data
565  ** is coming from a SELECT statement, then generate a co-routine that
566  ** produces a single row of the SELECT on each invocation.  The
567  ** co-routine is the common header to the 3rd and 4th templates.
568  */
569  if( pSelect ){
570    /* Data is coming from a SELECT.  Generate code to implement that SELECT
571    ** as a co-routine.  The code is common to both the 3rd and 4th
572    ** templates:
573    **
574    **         EOF <- 0
575    **         X <- A
576    **         goto B
577    **      A: setup for the SELECT
578    **         loop over the tables in the SELECT
579    **           load value into register R..R+n
580    **           yield X
581    **         end loop
582    **         cleanup after the SELECT
583    **         EOF <- 1
584    **         yield X
585    **         halt-error
586    **
587    ** On each invocation of the co-routine, it puts a single row of the
588    ** SELECT result into registers dest.iMem...dest.iMem+dest.nMem-1.
589    ** (These output registers are allocated by sqlite3Select().)  When
590    ** the SELECT completes, it sets the EOF flag stored in regEof.
591    */
592    int rc, j1;
593
594    regEof = ++pParse->nMem;
595    sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof);      /* EOF <- 0 */
596    VdbeComment((v, "SELECT eof flag"));
597    sqlite3SelectDestInit(&dest, SRT_Coroutine, ++pParse->nMem);
598    addrSelect = sqlite3VdbeCurrentAddr(v)+2;
599    sqlite3VdbeAddOp2(v, OP_Integer, addrSelect-1, dest.iParm);
600    j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
601    VdbeComment((v, "Jump over SELECT coroutine"));
602
603    /* Resolve the expressions in the SELECT statement and execute it. */
604    rc = sqlite3Select(pParse, pSelect, &dest);
605    assert( pParse->nErr==0 || rc );
606    if( rc || NEVER(pParse->nErr) || db->mallocFailed ){
607      goto insert_cleanup;
608    }
609    sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof);         /* EOF <- 1 */
610    sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);   /* yield X */
611    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
612    VdbeComment((v, "End of SELECT coroutine"));
613    sqlite3VdbeJumpHere(v, j1);                          /* label B: */
614
615    regFromSelect = dest.iMem;
616    assert( pSelect->pEList );
617    nColumn = pSelect->pEList->nExpr;
618    assert( dest.nMem==nColumn );
619
620    /* Set useTempTable to TRUE if the result of the SELECT statement
621    ** should be written into a temporary table (template 4).  Set to
622    ** FALSE if each* row of the SELECT can be written directly into
623    ** the destination table (template 3).
624    **
625    ** A temp table must be used if the table being updated is also one
626    ** of the tables being read by the SELECT statement.  Also use a
627    ** temp table in the case of row triggers.
628    */
629    if( pTrigger || readsTable(pParse, addrSelect, iDb, pTab) ){
630      useTempTable = 1;
631    }
632
633    if( useTempTable ){
634      /* Invoke the coroutine to extract information from the SELECT
635      ** and add it to a transient table srcTab.  The code generated
636      ** here is from the 4th template:
637      **
638      **      B: open temp table
639      **      L: yield X
640      **         if EOF goto M
641      **         insert row from R..R+n into temp table
642      **         goto L
643      **      M: ...
644      */
645      int regRec;          /* Register to hold packed record */
646      int regTempRowid;    /* Register to hold temp table ROWID */
647      int addrTop;         /* Label "L" */
648      int addrIf;          /* Address of jump to M */
649
650      srcTab = pParse->nTab++;
651      regRec = sqlite3GetTempReg(pParse);
652      regTempRowid = sqlite3GetTempReg(pParse);
653      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
654      addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
655      addrIf = sqlite3VdbeAddOp1(v, OP_If, regEof);
656      sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
657      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
658      sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
659      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
660      sqlite3VdbeJumpHere(v, addrIf);
661      sqlite3ReleaseTempReg(pParse, regRec);
662      sqlite3ReleaseTempReg(pParse, regTempRowid);
663    }
664  }else{
665    /* This is the case if the data for the INSERT is coming from a VALUES
666    ** clause
667    */
668    NameContext sNC;
669    memset(&sNC, 0, sizeof(sNC));
670    sNC.pParse = pParse;
671    srcTab = -1;
672    assert( useTempTable==0 );
673    nColumn = pList ? pList->nExpr : 0;
674    for(i=0; i<nColumn; i++){
675      if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
676        goto insert_cleanup;
677      }
678    }
679  }
680
681  /* Make sure the number of columns in the source data matches the number
682  ** of columns to be inserted into the table.
683  */
684  if( IsVirtual(pTab) ){
685    for(i=0; i<pTab->nCol; i++){
686      nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
687    }
688  }
689  if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
690    sqlite3ErrorMsg(pParse,
691       "table %S has %d columns but %d values were supplied",
692       pTabList, 0, pTab->nCol-nHidden, nColumn);
693    goto insert_cleanup;
694  }
695  if( pColumn!=0 && nColumn!=pColumn->nId ){
696    sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
697    goto insert_cleanup;
698  }
699
700  /* If the INSERT statement included an IDLIST term, then make sure
701  ** all elements of the IDLIST really are columns of the table and
702  ** remember the column indices.
703  **
704  ** If the table has an INTEGER PRIMARY KEY column and that column
705  ** is named in the IDLIST, then record in the keyColumn variable
706  ** the index into IDLIST of the primary key column.  keyColumn is
707  ** the index of the primary key as it appears in IDLIST, not as
708  ** is appears in the original table.  (The index of the primary
709  ** key in the original table is pTab->iPKey.)
710  */
711  if( pColumn ){
712    for(i=0; i<pColumn->nId; i++){
713      pColumn->a[i].idx = -1;
714    }
715    for(i=0; i<pColumn->nId; i++){
716      for(j=0; j<pTab->nCol; j++){
717        if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
718          pColumn->a[i].idx = j;
719          if( j==pTab->iPKey ){
720            keyColumn = i;
721          }
722          break;
723        }
724      }
725      if( j>=pTab->nCol ){
726        if( sqlite3IsRowid(pColumn->a[i].zName) ){
727          keyColumn = i;
728        }else{
729          sqlite3ErrorMsg(pParse, "table %S has no column named %s",
730              pTabList, 0, pColumn->a[i].zName);
731          pParse->checkSchema = 1;
732          goto insert_cleanup;
733        }
734      }
735    }
736  }
737
738  /* If there is no IDLIST term but the table has an integer primary
739  ** key, the set the keyColumn variable to the primary key column index
740  ** in the original table definition.
741  */
742  if( pColumn==0 && nColumn>0 ){
743    keyColumn = pTab->iPKey;
744  }
745
746  /* Initialize the count of rows to be inserted
747  */
748  if( db->flags & SQLITE_CountRows ){
749    regRowCount = ++pParse->nMem;
750    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
751  }
752
753  /* If this is not a view, open the table and and all indices */
754  if( !isView ){
755    int nIdx;
756
757    baseCur = pParse->nTab;
758    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, baseCur, OP_OpenWrite);
759    aRegIdx = sqlite3DbMallocRaw(db, sizeof(int)*(nIdx+1));
760    if( aRegIdx==0 ){
761      goto insert_cleanup;
762    }
763    for(i=0; i<nIdx; i++){
764      aRegIdx[i] = ++pParse->nMem;
765    }
766  }
767
768  /* This is the top of the main insertion loop */
769  if( useTempTable ){
770    /* This block codes the top of loop only.  The complete loop is the
771    ** following pseudocode (template 4):
772    **
773    **         rewind temp table
774    **      C: loop over rows of intermediate table
775    **           transfer values form intermediate table into <table>
776    **         end loop
777    **      D: ...
778    */
779    addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab);
780    addrCont = sqlite3VdbeCurrentAddr(v);
781  }else if( pSelect ){
782    /* This block codes the top of loop only.  The complete loop is the
783    ** following pseudocode (template 3):
784    **
785    **      C: yield X
786    **         if EOF goto D
787    **         insert the select result into <table> from R..R+n
788    **         goto C
789    **      D: ...
790    */
791    addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
792    addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof);
793  }
794
795  /* Allocate registers for holding the rowid of the new row,
796  ** the content of the new row, and the assemblied row record.
797  */
798  regRowid = regIns = pParse->nMem+1;
799  pParse->nMem += pTab->nCol + 1;
800  if( IsVirtual(pTab) ){
801    regRowid++;
802    pParse->nMem++;
803  }
804  regData = regRowid+1;
805
806  /* Run the BEFORE and INSTEAD OF triggers, if there are any
807  */
808  endOfLoop = sqlite3VdbeMakeLabel(v);
809  if( tmask & TRIGGER_BEFORE ){
810    int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);
811
812    /* build the NEW.* reference row.  Note that if there is an INTEGER
813    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
814    ** translated into a unique ID for the row.  But on a BEFORE trigger,
815    ** we do not know what the unique ID will be (because the insert has
816    ** not happened yet) so we substitute a rowid of -1
817    */
818    if( keyColumn<0 ){
819      sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
820    }else{
821      int j1;
822      if( useTempTable ){
823        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regCols);
824      }else{
825        assert( pSelect==0 );  /* Otherwise useTempTable is true */
826        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regCols);
827      }
828      j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols);
829      sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
830      sqlite3VdbeJumpHere(v, j1);
831      sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols);
832    }
833
834    /* Cannot have triggers on a virtual table. If it were possible,
835    ** this block would have to account for hidden column.
836    */
837    assert( !IsVirtual(pTab) );
838
839    /* Create the new column data
840    */
841    for(i=0; i<pTab->nCol; i++){
842      if( pColumn==0 ){
843        j = i;
844      }else{
845        for(j=0; j<pColumn->nId; j++){
846          if( pColumn->a[j].idx==i ) break;
847        }
848      }
849      if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId) ){
850        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);
851      }else if( useTempTable ){
852        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1);
853      }else{
854        assert( pSelect==0 ); /* Otherwise useTempTable is true */
855        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);
856      }
857    }
858
859    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
860    ** do not attempt any conversions before assembling the record.
861    ** If this is a real table, attempt conversions as required by the
862    ** table column affinities.
863    */
864    if( !isView ){
865      sqlite3VdbeAddOp2(v, OP_Affinity, regCols+1, pTab->nCol);
866      sqlite3TableAffinityStr(v, pTab);
867    }
868
869    /* Fire BEFORE or INSTEAD OF triggers */
870    sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE,
871        pTab, regCols-pTab->nCol-1, onError, endOfLoop);
872
873    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
874  }
875
876  /* Push the record number for the new entry onto the stack.  The
877  ** record number is a randomly generate integer created by NewRowid
878  ** except when the table has an INTEGER PRIMARY KEY column, in which
879  ** case the record number is the same as that column.
880  */
881  if( !isView ){
882    if( IsVirtual(pTab) ){
883      /* The row that the VUpdate opcode will delete: none */
884      sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
885    }
886    if( keyColumn>=0 ){
887      if( useTempTable ){
888        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
889      }else if( pSelect ){
890        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
891      }else{
892        VdbeOp *pOp;
893        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regRowid);
894        pOp = sqlite3VdbeGetOp(v, -1);
895        if( ALWAYS(pOp) && pOp->opcode==OP_Null && !IsVirtual(pTab) ){
896          appendFlag = 1;
897          pOp->opcode = OP_NewRowid;
898          pOp->p1 = baseCur;
899          pOp->p2 = regRowid;
900          pOp->p3 = regAutoinc;
901        }
902      }
903      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
904      ** to generate a unique primary key value.
905      */
906      if( !appendFlag ){
907        int j1;
908        if( !IsVirtual(pTab) ){
909          j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid);
910          sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
911          sqlite3VdbeJumpHere(v, j1);
912        }else{
913          j1 = sqlite3VdbeCurrentAddr(v);
914          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, j1+2);
915        }
916        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
917      }
918    }else if( IsVirtual(pTab) ){
919      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
920    }else{
921      sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
922      appendFlag = 1;
923    }
924    autoIncStep(pParse, regAutoinc, regRowid);
925
926    /* Push onto the stack, data for all columns of the new entry, beginning
927    ** with the first column.
928    */
929    nHidden = 0;
930    for(i=0; i<pTab->nCol; i++){
931      int iRegStore = regRowid+1+i;
932      if( i==pTab->iPKey ){
933        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
934        ** Whenever this column is read, the record number will be substituted
935        ** in its place.  So will fill this column with a NULL to avoid
936        ** taking up data space with information that will never be used. */
937        sqlite3VdbeAddOp2(v, OP_Null, 0, iRegStore);
938        continue;
939      }
940      if( pColumn==0 ){
941        if( IsHiddenColumn(&pTab->aCol[i]) ){
942          assert( IsVirtual(pTab) );
943          j = -1;
944          nHidden++;
945        }else{
946          j = i - nHidden;
947        }
948      }else{
949        for(j=0; j<pColumn->nId; j++){
950          if( pColumn->a[j].idx==i ) break;
951        }
952      }
953      if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
954        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, iRegStore);
955      }else if( useTempTable ){
956        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore);
957      }else if( pSelect ){
958        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
959      }else{
960        sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);
961      }
962    }
963
964    /* Generate code to check constraints and generate index keys and
965    ** do the insertion.
966    */
967#ifndef SQLITE_OMIT_VIRTUALTABLE
968    if( IsVirtual(pTab) ){
969      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
970      sqlite3VtabMakeWritable(pParse, pTab);
971      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
972      sqlite3MayAbort(pParse);
973    }else
974#endif
975    {
976      int isReplace;    /* Set to true if constraints may cause a replace */
977      sqlite3GenerateConstraintChecks(pParse, pTab, baseCur, regIns, aRegIdx,
978          keyColumn>=0, 0, onError, endOfLoop, &isReplace
979      );
980      sqlite3FkCheck(pParse, pTab, 0, regIns);
981      sqlite3CompleteInsertion(
982          pParse, pTab, baseCur, regIns, aRegIdx, 0, appendFlag, isReplace==0
983      );
984    }
985  }
986
987  /* Update the count of rows that are inserted
988  */
989  if( (db->flags & SQLITE_CountRows)!=0 ){
990    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
991  }
992
993  if( pTrigger ){
994    /* Code AFTER triggers */
995    sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER,
996        pTab, regData-2-pTab->nCol, onError, endOfLoop);
997  }
998
999  /* The bottom of the main insertion loop, if the data source
1000  ** is a SELECT statement.
1001  */
1002  sqlite3VdbeResolveLabel(v, endOfLoop);
1003  if( useTempTable ){
1004    sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont);
1005    sqlite3VdbeJumpHere(v, addrInsTop);
1006    sqlite3VdbeAddOp1(v, OP_Close, srcTab);
1007  }else if( pSelect ){
1008    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrCont);
1009    sqlite3VdbeJumpHere(v, addrInsTop);
1010  }
1011
1012  if( !IsVirtual(pTab) && !isView ){
1013    /* Close all tables opened */
1014    sqlite3VdbeAddOp1(v, OP_Close, baseCur);
1015    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
1016      sqlite3VdbeAddOp1(v, OP_Close, idx+baseCur);
1017    }
1018  }
1019
1020insert_end:
1021  /* Update the sqlite_sequence table by storing the content of the
1022  ** maximum rowid counter values recorded while inserting into
1023  ** autoincrement tables.
1024  */
1025  if( pParse->nested==0 && pParse->pTriggerTab==0 ){
1026    sqlite3AutoincrementEnd(pParse);
1027  }
1028
1029  /*
1030  ** Return the number of rows inserted. If this routine is
1031  ** generating code because of a call to sqlite3NestedParse(), do not
1032  ** invoke the callback function.
1033  */
1034  if( (db->flags&SQLITE_CountRows) && !pParse->nested && !pParse->pTriggerTab ){
1035    sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
1036    sqlite3VdbeSetNumCols(v, 1);
1037    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", SQLITE_STATIC);
1038  }
1039
1040insert_cleanup:
1041  sqlite3SrcListDelete(db, pTabList);
1042  sqlite3ExprListDelete(db, pList);
1043  sqlite3SelectDelete(db, pSelect);
1044  sqlite3IdListDelete(db, pColumn);
1045  sqlite3DbFree(db, aRegIdx);
1046}
1047
1048/* Make sure "isView" and other macros defined above are undefined. Otherwise
1049** thely may interfere with compilation of other functions in this file
1050** (or in another file, if this file becomes part of the amalgamation).  */
1051#ifdef isView
1052 #undef isView
1053#endif
1054#ifdef pTrigger
1055 #undef pTrigger
1056#endif
1057#ifdef tmask
1058 #undef tmask
1059#endif
1060
1061
1062/*
1063** Generate code to do constraint checks prior to an INSERT or an UPDATE.
1064**
1065** The input is a range of consecutive registers as follows:
1066**
1067**    1.  The rowid of the row after the update.
1068**
1069**    2.  The data in the first column of the entry after the update.
1070**
1071**    i.  Data from middle columns...
1072**
1073**    N.  The data in the last column of the entry after the update.
1074**
1075** The regRowid parameter is the index of the register containing (1).
1076**
1077** If isUpdate is true and rowidChng is non-zero, then rowidChng contains
1078** the address of a register containing the rowid before the update takes
1079** place. isUpdate is true for UPDATEs and false for INSERTs. If isUpdate
1080** is false, indicating an INSERT statement, then a non-zero rowidChng
1081** indicates that the rowid was explicitly specified as part of the
1082** INSERT statement. If rowidChng is false, it means that  the rowid is
1083** computed automatically in an insert or that the rowid value is not
1084** modified by an update.
1085**
1086** The code generated by this routine store new index entries into
1087** registers identified by aRegIdx[].  No index entry is created for
1088** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
1089** the same as the order of indices on the linked list of indices
1090** attached to the table.
1091**
1092** This routine also generates code to check constraints.  NOT NULL,
1093** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
1094** then the appropriate action is performed.  There are five possible
1095** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
1096**
1097**  Constraint type  Action       What Happens
1098**  ---------------  ----------   ----------------------------------------
1099**  any              ROLLBACK     The current transaction is rolled back and
1100**                                sqlite3_exec() returns immediately with a
1101**                                return code of SQLITE_CONSTRAINT.
1102**
1103**  any              ABORT        Back out changes from the current command
1104**                                only (do not do a complete rollback) then
1105**                                cause sqlite3_exec() to return immediately
1106**                                with SQLITE_CONSTRAINT.
1107**
1108**  any              FAIL         Sqlite_exec() returns immediately with a
1109**                                return code of SQLITE_CONSTRAINT.  The
1110**                                transaction is not rolled back and any
1111**                                prior changes are retained.
1112**
1113**  any              IGNORE       The record number and data is popped from
1114**                                the stack and there is an immediate jump
1115**                                to label ignoreDest.
1116**
1117**  NOT NULL         REPLACE      The NULL value is replace by the default
1118**                                value for that column.  If the default value
1119**                                is NULL, the action is the same as ABORT.
1120**
1121**  UNIQUE           REPLACE      The other row that conflicts with the row
1122**                                being inserted is removed.
1123**
1124**  CHECK            REPLACE      Illegal.  The results in an exception.
1125**
1126** Which action to take is determined by the overrideError parameter.
1127** Or if overrideError==OE_Default, then the pParse->onError parameter
1128** is used.  Or if pParse->onError==OE_Default then the onError value
1129** for the constraint is used.
1130**
1131** The calling routine must open a read/write cursor for pTab with
1132** cursor number "baseCur".  All indices of pTab must also have open
1133** read/write cursors with cursor number baseCur+i for the i-th cursor.
1134** Except, if there is no possibility of a REPLACE action then
1135** cursors do not need to be open for indices where aRegIdx[i]==0.
1136*/
1137void sqlite3GenerateConstraintChecks(
1138  Parse *pParse,      /* The parser context */
1139  Table *pTab,        /* the table into which we are inserting */
1140  int baseCur,        /* Index of a read/write cursor pointing at pTab */
1141  int regRowid,       /* Index of the range of input registers */
1142  int *aRegIdx,       /* Register used by each index.  0 for unused indices */
1143  int rowidChng,      /* True if the rowid might collide with existing entry */
1144  int isUpdate,       /* True for UPDATE, False for INSERT */
1145  int overrideError,  /* Override onError to this if not OE_Default */
1146  int ignoreDest,     /* Jump to this label on an OE_Ignore resolution */
1147  int *pbMayReplace   /* OUT: Set to true if constraint may cause a replace */
1148){
1149  int i;              /* loop counter */
1150  Vdbe *v;            /* VDBE under constrution */
1151  int nCol;           /* Number of columns */
1152  int onError;        /* Conflict resolution strategy */
1153  int j1;             /* Addresss of jump instruction */
1154  int j2 = 0, j3;     /* Addresses of jump instructions */
1155  int regData;        /* Register containing first data column */
1156  int iCur;           /* Table cursor number */
1157  Index *pIdx;         /* Pointer to one of the indices */
1158  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
1159  int regOldRowid = (rowidChng && isUpdate) ? rowidChng : regRowid;
1160
1161  v = sqlite3GetVdbe(pParse);
1162  assert( v!=0 );
1163  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
1164  nCol = pTab->nCol;
1165  regData = regRowid + 1;
1166
1167  /* Test all NOT NULL constraints.
1168  */
1169  for(i=0; i<nCol; i++){
1170    if( i==pTab->iPKey ){
1171      continue;
1172    }
1173    onError = pTab->aCol[i].notNull;
1174    if( onError==OE_None ) continue;
1175    if( overrideError!=OE_Default ){
1176      onError = overrideError;
1177    }else if( onError==OE_Default ){
1178      onError = OE_Abort;
1179    }
1180    if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
1181      onError = OE_Abort;
1182    }
1183    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1184        || onError==OE_Ignore || onError==OE_Replace );
1185    switch( onError ){
1186      case OE_Abort:
1187        sqlite3MayAbort(pParse);
1188      case OE_Rollback:
1189      case OE_Fail: {
1190        char *zMsg;
1191        sqlite3VdbeAddOp3(v, OP_HaltIfNull,
1192                                  SQLITE_CONSTRAINT, onError, regData+i);
1193        zMsg = sqlite3MPrintf(pParse->db, "%s.%s may not be NULL",
1194                              pTab->zName, pTab->aCol[i].zName);
1195        sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
1196        break;
1197      }
1198      case OE_Ignore: {
1199        sqlite3VdbeAddOp2(v, OP_IsNull, regData+i, ignoreDest);
1200        break;
1201      }
1202      default: {
1203        assert( onError==OE_Replace );
1204        j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regData+i);
1205        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regData+i);
1206        sqlite3VdbeJumpHere(v, j1);
1207        break;
1208      }
1209    }
1210  }
1211
1212  /* Test all CHECK constraints
1213  */
1214#ifndef SQLITE_OMIT_CHECK
1215  if( pTab->pCheck && (pParse->db->flags & SQLITE_IgnoreChecks)==0 ){
1216    int allOk = sqlite3VdbeMakeLabel(v);
1217    pParse->ckBase = regData;
1218    sqlite3ExprIfTrue(pParse, pTab->pCheck, allOk, SQLITE_JUMPIFNULL);
1219    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
1220    if( onError==OE_Ignore ){
1221      sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
1222    }else{
1223      if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
1224      sqlite3HaltConstraint(pParse, onError, 0, 0);
1225    }
1226    sqlite3VdbeResolveLabel(v, allOk);
1227  }
1228#endif /* !defined(SQLITE_OMIT_CHECK) */
1229
1230  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
1231  ** of the new record does not previously exist.  Except, if this
1232  ** is an UPDATE and the primary key is not changing, that is OK.
1233  */
1234  if( rowidChng ){
1235    onError = pTab->keyConf;
1236    if( overrideError!=OE_Default ){
1237      onError = overrideError;
1238    }else if( onError==OE_Default ){
1239      onError = OE_Abort;
1240    }
1241
1242    if( isUpdate ){
1243      j2 = sqlite3VdbeAddOp3(v, OP_Eq, regRowid, 0, rowidChng);
1244    }
1245    j3 = sqlite3VdbeAddOp3(v, OP_NotExists, baseCur, 0, regRowid);
1246    switch( onError ){
1247      default: {
1248        onError = OE_Abort;
1249        /* Fall thru into the next case */
1250      }
1251      case OE_Rollback:
1252      case OE_Abort:
1253      case OE_Fail: {
1254        sqlite3HaltConstraint(
1255          pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
1256        break;
1257      }
1258      case OE_Replace: {
1259        /* If there are DELETE triggers on this table and the
1260        ** recursive-triggers flag is set, call GenerateRowDelete() to
1261        ** remove the conflicting row from the the table. This will fire
1262        ** the triggers and remove both the table and index b-tree entries.
1263        **
1264        ** Otherwise, if there are no triggers or the recursive-triggers
1265        ** flag is not set, but the table has one or more indexes, call
1266        ** GenerateRowIndexDelete(). This removes the index b-tree entries
1267        ** only. The table b-tree entry will be replaced by the new entry
1268        ** when it is inserted.
1269        **
1270        ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
1271        ** also invoke MultiWrite() to indicate that this VDBE may require
1272        ** statement rollback (if the statement is aborted after the delete
1273        ** takes place). Earlier versions called sqlite3MultiWrite() regardless,
1274        ** but being more selective here allows statements like:
1275        **
1276        **   REPLACE INTO t(rowid) VALUES($newrowid)
1277        **
1278        ** to run without a statement journal if there are no indexes on the
1279        ** table.
1280        */
1281        Trigger *pTrigger = 0;
1282        if( pParse->db->flags&SQLITE_RecTriggers ){
1283          pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1284        }
1285        if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
1286          sqlite3MultiWrite(pParse);
1287          sqlite3GenerateRowDelete(
1288              pParse, pTab, baseCur, regRowid, 0, pTrigger, OE_Replace
1289          );
1290        }else if( pTab->pIndex ){
1291          sqlite3MultiWrite(pParse);
1292          sqlite3GenerateRowIndexDelete(pParse, pTab, baseCur, 0);
1293        }
1294        seenReplace = 1;
1295        break;
1296      }
1297      case OE_Ignore: {
1298        assert( seenReplace==0 );
1299        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
1300        break;
1301      }
1302    }
1303    sqlite3VdbeJumpHere(v, j3);
1304    if( isUpdate ){
1305      sqlite3VdbeJumpHere(v, j2);
1306    }
1307  }
1308
1309  /* Test all UNIQUE constraints by creating entries for each UNIQUE
1310  ** index and making sure that duplicate entries do not already exist.
1311  ** Add the new records to the indices as we go.
1312  */
1313  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
1314    int regIdx;
1315    int regR;
1316
1317    if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */
1318
1319    /* Create a key for accessing the index entry */
1320    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
1321    for(i=0; i<pIdx->nColumn; i++){
1322      int idx = pIdx->aiColumn[i];
1323      if( idx==pTab->iPKey ){
1324        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
1325      }else{
1326        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
1327      }
1328    }
1329    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
1330    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
1331    sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
1332    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn+1);
1333
1334    /* Find out what action to take in case there is an indexing conflict */
1335    onError = pIdx->onError;
1336    if( onError==OE_None ){
1337      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
1338      continue;  /* pIdx is not a UNIQUE index */
1339    }
1340    if( overrideError!=OE_Default ){
1341      onError = overrideError;
1342    }else if( onError==OE_Default ){
1343      onError = OE_Abort;
1344    }
1345    if( seenReplace ){
1346      if( onError==OE_Ignore ) onError = OE_Replace;
1347      else if( onError==OE_Fail ) onError = OE_Abort;
1348    }
1349
1350    /* Check to see if the new index entry will be unique */
1351    regR = sqlite3GetTempReg(pParse);
1352    sqlite3VdbeAddOp2(v, OP_SCopy, regOldRowid, regR);
1353    j3 = sqlite3VdbeAddOp4(v, OP_IsUnique, baseCur+iCur+1, 0,
1354                           regR, SQLITE_INT_TO_PTR(regIdx),
1355                           P4_INT32);
1356    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
1357
1358    /* Generate code that executes if the new index entry is not unique */
1359    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1360        || onError==OE_Ignore || onError==OE_Replace );
1361    switch( onError ){
1362      case OE_Rollback:
1363      case OE_Abort:
1364      case OE_Fail: {
1365        int j;
1366        StrAccum errMsg;
1367        const char *zSep;
1368        char *zErr;
1369
1370        sqlite3StrAccumInit(&errMsg, 0, 0, 200);
1371        errMsg.db = pParse->db;
1372        zSep = pIdx->nColumn>1 ? "columns " : "column ";
1373        for(j=0; j<pIdx->nColumn; j++){
1374          char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
1375          sqlite3StrAccumAppend(&errMsg, zSep, -1);
1376          zSep = ", ";
1377          sqlite3StrAccumAppend(&errMsg, zCol, -1);
1378        }
1379        sqlite3StrAccumAppend(&errMsg,
1380            pIdx->nColumn>1 ? " are not unique" : " is not unique", -1);
1381        zErr = sqlite3StrAccumFinish(&errMsg);
1382        sqlite3HaltConstraint(pParse, onError, zErr, 0);
1383        sqlite3DbFree(errMsg.db, zErr);
1384        break;
1385      }
1386      case OE_Ignore: {
1387        assert( seenReplace==0 );
1388        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
1389        break;
1390      }
1391      default: {
1392        Trigger *pTrigger = 0;
1393        assert( onError==OE_Replace );
1394        sqlite3MultiWrite(pParse);
1395        if( pParse->db->flags&SQLITE_RecTriggers ){
1396          pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1397        }
1398        sqlite3GenerateRowDelete(
1399            pParse, pTab, baseCur, regR, 0, pTrigger, OE_Replace
1400        );
1401        seenReplace = 1;
1402        break;
1403      }
1404    }
1405    sqlite3VdbeJumpHere(v, j3);
1406    sqlite3ReleaseTempReg(pParse, regR);
1407  }
1408
1409  if( pbMayReplace ){
1410    *pbMayReplace = seenReplace;
1411  }
1412}
1413
1414/*
1415** This routine generates code to finish the INSERT or UPDATE operation
1416** that was started by a prior call to sqlite3GenerateConstraintChecks.
1417** A consecutive range of registers starting at regRowid contains the
1418** rowid and the content to be inserted.
1419**
1420** The arguments to this routine should be the same as the first six
1421** arguments to sqlite3GenerateConstraintChecks.
1422*/
1423void sqlite3CompleteInsertion(
1424  Parse *pParse,      /* The parser context */
1425  Table *pTab,        /* the table into which we are inserting */
1426  int baseCur,        /* Index of a read/write cursor pointing at pTab */
1427  int regRowid,       /* Range of content */
1428  int *aRegIdx,       /* Register used by each index.  0 for unused indices */
1429  int isUpdate,       /* True for UPDATE, False for INSERT */
1430  int appendBias,     /* True if this is likely to be an append */
1431  int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
1432){
1433  int i;
1434  Vdbe *v;
1435  int nIdx;
1436  Index *pIdx;
1437  u8 pik_flags;
1438  int regData;
1439  int regRec;
1440
1441  v = sqlite3GetVdbe(pParse);
1442  assert( v!=0 );
1443  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
1444  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
1445  for(i=nIdx-1; i>=0; i--){
1446    if( aRegIdx[i]==0 ) continue;
1447    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
1448    if( useSeekResult ){
1449      sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
1450    }
1451  }
1452  regData = regRowid + 1;
1453  regRec = sqlite3GetTempReg(pParse);
1454  sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
1455  sqlite3TableAffinityStr(v, pTab);
1456  sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
1457  if( pParse->nested ){
1458    pik_flags = 0;
1459  }else{
1460    pik_flags = OPFLAG_NCHANGE;
1461    pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
1462  }
1463  if( appendBias ){
1464    pik_flags |= OPFLAG_APPEND;
1465  }
1466  if( useSeekResult ){
1467    pik_flags |= OPFLAG_USESEEKRESULT;
1468  }
1469  sqlite3VdbeAddOp3(v, OP_Insert, baseCur, regRec, regRowid);
1470  if( !pParse->nested ){
1471    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
1472  }
1473  sqlite3VdbeChangeP5(v, pik_flags);
1474}
1475
1476/*
1477** Generate code that will open cursors for a table and for all
1478** indices of that table.  The "baseCur" parameter is the cursor number used
1479** for the table.  Indices are opened on subsequent cursors.
1480**
1481** Return the number of indices on the table.
1482*/
1483int sqlite3OpenTableAndIndices(
1484  Parse *pParse,   /* Parsing context */
1485  Table *pTab,     /* Table to be opened */
1486  int baseCur,     /* Cursor number assigned to the table */
1487  int op           /* OP_OpenRead or OP_OpenWrite */
1488){
1489  int i;
1490  int iDb;
1491  Index *pIdx;
1492  Vdbe *v;
1493
1494  if( IsVirtual(pTab) ) return 0;
1495  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
1496  v = sqlite3GetVdbe(pParse);
1497  assert( v!=0 );
1498  sqlite3OpenTable(pParse, baseCur, iDb, pTab, op);
1499  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
1500    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
1501    assert( pIdx->pSchema==pTab->pSchema );
1502    sqlite3VdbeAddOp4(v, op, i+baseCur, pIdx->tnum, iDb,
1503                      (char*)pKey, P4_KEYINFO_HANDOFF);
1504    VdbeComment((v, "%s", pIdx->zName));
1505  }
1506  if( pParse->nTab<baseCur+i ){
1507    pParse->nTab = baseCur+i;
1508  }
1509  return i-1;
1510}
1511
1512
1513#ifdef SQLITE_TEST
1514/*
1515** The following global variable is incremented whenever the
1516** transfer optimization is used.  This is used for testing
1517** purposes only - to make sure the transfer optimization really
1518** is happening when it is suppose to.
1519*/
1520int sqlite3_xferopt_count;
1521#endif /* SQLITE_TEST */
1522
1523
1524#ifndef SQLITE_OMIT_XFER_OPT
1525/*
1526** Check to collation names to see if they are compatible.
1527*/
1528static int xferCompatibleCollation(const char *z1, const char *z2){
1529  if( z1==0 ){
1530    return z2==0;
1531  }
1532  if( z2==0 ){
1533    return 0;
1534  }
1535  return sqlite3StrICmp(z1, z2)==0;
1536}
1537
1538
1539/*
1540** Check to see if index pSrc is compatible as a source of data
1541** for index pDest in an insert transfer optimization.  The rules
1542** for a compatible index:
1543**
1544**    *   The index is over the same set of columns
1545**    *   The same DESC and ASC markings occurs on all columns
1546**    *   The same onError processing (OE_Abort, OE_Ignore, etc)
1547**    *   The same collating sequence on each column
1548*/
1549static int xferCompatibleIndex(Index *pDest, Index *pSrc){
1550  int i;
1551  assert( pDest && pSrc );
1552  assert( pDest->pTable!=pSrc->pTable );
1553  if( pDest->nColumn!=pSrc->nColumn ){
1554    return 0;   /* Different number of columns */
1555  }
1556  if( pDest->onError!=pSrc->onError ){
1557    return 0;   /* Different conflict resolution strategies */
1558  }
1559  for(i=0; i<pSrc->nColumn; i++){
1560    if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
1561      return 0;   /* Different columns indexed */
1562    }
1563    if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
1564      return 0;   /* Different sort orders */
1565    }
1566    if( !xferCompatibleCollation(pSrc->azColl[i],pDest->azColl[i]) ){
1567      return 0;   /* Different collating sequences */
1568    }
1569  }
1570
1571  /* If no test above fails then the indices must be compatible */
1572  return 1;
1573}
1574
1575/*
1576** Attempt the transfer optimization on INSERTs of the form
1577**
1578**     INSERT INTO tab1 SELECT * FROM tab2;
1579**
1580** This optimization is only attempted if
1581**
1582**    (1)  tab1 and tab2 have identical schemas including all the
1583**         same indices and constraints
1584**
1585**    (2)  tab1 and tab2 are different tables
1586**
1587**    (3)  There must be no triggers on tab1
1588**
1589**    (4)  The result set of the SELECT statement is "*"
1590**
1591**    (5)  The SELECT statement has no WHERE, HAVING, ORDER BY, GROUP BY,
1592**         or LIMIT clause.
1593**
1594**    (6)  The SELECT statement is a simple (not a compound) select that
1595**         contains only tab2 in its FROM clause
1596**
1597** This method for implementing the INSERT transfers raw records from
1598** tab2 over to tab1.  The columns are not decoded.  Raw records from
1599** the indices of tab2 are transfered to tab1 as well.  In so doing,
1600** the resulting tab1 has much less fragmentation.
1601**
1602** This routine returns TRUE if the optimization is attempted.  If any
1603** of the conditions above fail so that the optimization should not
1604** be attempted, then this routine returns FALSE.
1605*/
1606static int xferOptimization(
1607  Parse *pParse,        /* Parser context */
1608  Table *pDest,         /* The table we are inserting into */
1609  Select *pSelect,      /* A SELECT statement to use as the data source */
1610  int onError,          /* How to handle constraint errors */
1611  int iDbDest           /* The database of pDest */
1612){
1613  ExprList *pEList;                /* The result set of the SELECT */
1614  Table *pSrc;                     /* The table in the FROM clause of SELECT */
1615  Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
1616  struct SrcList_item *pItem;      /* An element of pSelect->pSrc */
1617  int i;                           /* Loop counter */
1618  int iDbSrc;                      /* The database of pSrc */
1619  int iSrc, iDest;                 /* Cursors from source and destination */
1620  int addr1, addr2;                /* Loop addresses */
1621  int emptyDestTest;               /* Address of test for empty pDest */
1622  int emptySrcTest;                /* Address of test for empty pSrc */
1623  Vdbe *v;                         /* The VDBE we are building */
1624  KeyInfo *pKey;                   /* Key information for an index */
1625  int regAutoinc;                  /* Memory register used by AUTOINC */
1626  int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
1627  int regData, regRowid;           /* Registers holding data and rowid */
1628
1629  if( pSelect==0 ){
1630    return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
1631  }
1632  if( sqlite3TriggerList(pParse, pDest) ){
1633    return 0;   /* tab1 must not have triggers */
1634  }
1635#ifndef SQLITE_OMIT_VIRTUALTABLE
1636  if( pDest->tabFlags & TF_Virtual ){
1637    return 0;   /* tab1 must not be a virtual table */
1638  }
1639#endif
1640  if( onError==OE_Default ){
1641    onError = OE_Abort;
1642  }
1643  if( onError!=OE_Abort && onError!=OE_Rollback ){
1644    return 0;   /* Cannot do OR REPLACE or OR IGNORE or OR FAIL */
1645  }
1646  assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
1647  if( pSelect->pSrc->nSrc!=1 ){
1648    return 0;   /* FROM clause must have exactly one term */
1649  }
1650  if( pSelect->pSrc->a[0].pSelect ){
1651    return 0;   /* FROM clause cannot contain a subquery */
1652  }
1653  if( pSelect->pWhere ){
1654    return 0;   /* SELECT may not have a WHERE clause */
1655  }
1656  if( pSelect->pOrderBy ){
1657    return 0;   /* SELECT may not have an ORDER BY clause */
1658  }
1659  /* Do not need to test for a HAVING clause.  If HAVING is present but
1660  ** there is no ORDER BY, we will get an error. */
1661  if( pSelect->pGroupBy ){
1662    return 0;   /* SELECT may not have a GROUP BY clause */
1663  }
1664  if( pSelect->pLimit ){
1665    return 0;   /* SELECT may not have a LIMIT clause */
1666  }
1667  assert( pSelect->pOffset==0 );  /* Must be so if pLimit==0 */
1668  if( pSelect->pPrior ){
1669    return 0;   /* SELECT may not be a compound query */
1670  }
1671  if( pSelect->selFlags & SF_Distinct ){
1672    return 0;   /* SELECT may not be DISTINCT */
1673  }
1674  pEList = pSelect->pEList;
1675  assert( pEList!=0 );
1676  if( pEList->nExpr!=1 ){
1677    return 0;   /* The result set must have exactly one column */
1678  }
1679  assert( pEList->a[0].pExpr );
1680  if( pEList->a[0].pExpr->op!=TK_ALL ){
1681    return 0;   /* The result set must be the special operator "*" */
1682  }
1683
1684  /* At this point we have established that the statement is of the
1685  ** correct syntactic form to participate in this optimization.  Now
1686  ** we have to check the semantics.
1687  */
1688  pItem = pSelect->pSrc->a;
1689  pSrc = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
1690  if( pSrc==0 ){
1691    return 0;   /* FROM clause does not contain a real table */
1692  }
1693  if( pSrc==pDest ){
1694    return 0;   /* tab1 and tab2 may not be the same table */
1695  }
1696#ifndef SQLITE_OMIT_VIRTUALTABLE
1697  if( pSrc->tabFlags & TF_Virtual ){
1698    return 0;   /* tab2 must not be a virtual table */
1699  }
1700#endif
1701  if( pSrc->pSelect ){
1702    return 0;   /* tab2 may not be a view */
1703  }
1704  if( pDest->nCol!=pSrc->nCol ){
1705    return 0;   /* Number of columns must be the same in tab1 and tab2 */
1706  }
1707  if( pDest->iPKey!=pSrc->iPKey ){
1708    return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
1709  }
1710  for(i=0; i<pDest->nCol; i++){
1711    if( pDest->aCol[i].affinity!=pSrc->aCol[i].affinity ){
1712      return 0;    /* Affinity must be the same on all columns */
1713    }
1714    if( !xferCompatibleCollation(pDest->aCol[i].zColl, pSrc->aCol[i].zColl) ){
1715      return 0;    /* Collating sequence must be the same on all columns */
1716    }
1717    if( pDest->aCol[i].notNull && !pSrc->aCol[i].notNull ){
1718      return 0;    /* tab2 must be NOT NULL if tab1 is */
1719    }
1720  }
1721  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
1722    if( pDestIdx->onError!=OE_None ){
1723      destHasUniqueIdx = 1;
1724    }
1725    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
1726      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
1727    }
1728    if( pSrcIdx==0 ){
1729      return 0;    /* pDestIdx has no corresponding index in pSrc */
1730    }
1731  }
1732#ifndef SQLITE_OMIT_CHECK
1733  if( pDest->pCheck && sqlite3ExprCompare(pSrc->pCheck, pDest->pCheck) ){
1734    return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
1735  }
1736#endif
1737
1738  /* If we get this far, it means either:
1739  **
1740  **    *   We can always do the transfer if the table contains an
1741  **        an integer primary key
1742  **
1743  **    *   We can conditionally do the transfer if the destination
1744  **        table is empty.
1745  */
1746#ifdef SQLITE_TEST
1747  sqlite3_xferopt_count++;
1748#endif
1749  iDbSrc = sqlite3SchemaToIndex(pParse->db, pSrc->pSchema);
1750  v = sqlite3GetVdbe(pParse);
1751  sqlite3CodeVerifySchema(pParse, iDbSrc);
1752  iSrc = pParse->nTab++;
1753  iDest = pParse->nTab++;
1754  regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
1755  sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
1756  if( (pDest->iPKey<0 && pDest->pIndex!=0) || destHasUniqueIdx ){
1757    /* If tables do not have an INTEGER PRIMARY KEY and there
1758    ** are indices to be copied and the destination is not empty,
1759    ** we have to disallow the transfer optimization because the
1760    ** the rowids might change which will mess up indexing.
1761    **
1762    ** Or if the destination has a UNIQUE index and is not empty,
1763    ** we also disallow the transfer optimization because we cannot
1764    ** insure that all entries in the union of DEST and SRC will be
1765    ** unique.
1766    */
1767    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0);
1768    emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
1769    sqlite3VdbeJumpHere(v, addr1);
1770  }else{
1771    emptyDestTest = 0;
1772  }
1773  sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
1774  emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
1775  regData = sqlite3GetTempReg(pParse);
1776  regRowid = sqlite3GetTempReg(pParse);
1777  if( pDest->iPKey>=0 ){
1778    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
1779    addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
1780    sqlite3HaltConstraint(
1781        pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
1782    sqlite3VdbeJumpHere(v, addr2);
1783    autoIncStep(pParse, regAutoinc, regRowid);
1784  }else if( pDest->pIndex==0 ){
1785    addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
1786  }else{
1787    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
1788    assert( (pDest->tabFlags & TF_Autoincrement)==0 );
1789  }
1790  sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
1791  sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
1792  sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
1793  sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
1794  sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1);
1795  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
1796    for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
1797      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
1798    }
1799    assert( pSrcIdx );
1800    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
1801    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
1802    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
1803    sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
1804                      (char*)pKey, P4_KEYINFO_HANDOFF);
1805    VdbeComment((v, "%s", pSrcIdx->zName));
1806    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
1807    sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
1808                      (char*)pKey, P4_KEYINFO_HANDOFF);
1809    VdbeComment((v, "%s", pDestIdx->zName));
1810    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
1811    sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
1812    sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
1813    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
1814    sqlite3VdbeJumpHere(v, addr1);
1815  }
1816  sqlite3VdbeJumpHere(v, emptySrcTest);
1817  sqlite3ReleaseTempReg(pParse, regRowid);
1818  sqlite3ReleaseTempReg(pParse, regData);
1819  sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
1820  sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
1821  if( emptyDestTest ){
1822    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
1823    sqlite3VdbeJumpHere(v, emptyDestTest);
1824    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
1825    return 0;
1826  }else{
1827    return 1;
1828  }
1829}
1830#endif /* SQLITE_OMIT_XFER_OPT */
1831