src/delete.c

   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 ** in order to generate code for DELETE FROM statements.
  14 */
  15 #include "sqliteInt.h"
  16
  17 /*
  18 ** While a SrcList can in general represent multiple tables and subqueries
  19 ** (as in the FROM clause of a SELECT statement) in this case it contains
  20 ** the name of a single table, as one might find in an INSERT, DELETE,
  21 ** or UPDATE statement.  Look up that table in the symbol table and
  22 ** return a pointer.  Set an error message and return NULL if the table
  23 ** name is not found or if any other error occurs.
  24 **
  25 ** The following fields are initialized appropriate in pSrc:
  26 **
  27 **    pSrc->a[0].pTab       Pointer to the Table object
  28 **    pSrc->a[0].pIndex     Pointer to the INDEXED BY index, if there is one
  29 **
  30 */
  31 Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
  32   SrcItem *pItem = pSrc->a;
  33   Table *pTab;
  34   assert( pItem && pSrc->nSrc>=1 );
  35   pTab = sqlite3LocateTableItem(pParse, 0, pItem);
  36   sqlite3DeleteTable(pParse->db, pItem->pTab);
  37   pItem->pTab = pTab;
  38   if( pTab ){
  39     pTab->nTabRef++;
  40     if( pItem->fg.isIndexedBy && sqlite3IndexedByLookup(pParse, pItem) ){
  41       pTab = 0;
  42     }
  43   }
  44   return pTab;
  45 }
  46
  47 /* Generate byte-code that will report the number of rows modified
  48 ** by a DELETE, INSERT, or UPDATE statement.
  49 */
  50 void sqlite3CodeChangeCount(Vdbe *v, int regCounter, const char *zColName){
  51   sqlite3VdbeAddOp0(v, OP_FkCheck);
  52   sqlite3VdbeAddOp2(v, OP_ResultRow, regCounter, 1);
  53   sqlite3VdbeSetNumCols(v, 1);
  54   sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zColName, SQLITE_STATIC);
  55 }
  56
  57 /* Return true if table pTab is read-only.
  58 **
  59 ** A table is read-only if any of the following are true:
  60 **
  61 **   1) It is a virtual table and no implementation of the xUpdate method
  62 **      has been provided
  63 **
  64 **   2) It is a system table (i.e. sqlite_schema), this call is not
  65 **      part of a nested parse and writable_schema pragma has not
  66 **      been specified
  67 **
  68 **   3) The table is a shadow table, the database connection is in
  69 **      defensive mode, and the current sqlite3_prepare()
  70 **      is for a top-level SQL statement.
  71 */
  72 static int tabIsReadOnly(Parse *pParse, Table *pTab){
  73   sqlite3 *db;
  74   if( IsVirtual(pTab) ){
  75     return sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0;
  76   }
  77   if( (pTab->tabFlags & (TF_Readonly|TF_Shadow))==0 ) return 0;
  78   db = pParse->db;
  79   if( (pTab->tabFlags & TF_Readonly)!=0 ){
  80     return sqlite3WritableSchema(db)==0 && pParse->nested==0;
  81   }
  82   assert( pTab->tabFlags & TF_Shadow );
  83   return sqlite3ReadOnlyShadowTables(db);
  84 }
  85
  86 /*
  87 ** Check to make sure the given table is writable.  If it is not
  88 ** writable, generate an error message and return 1.  If it is
  89 ** writable return 0;
  90 */
  91 int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
  92   if( tabIsReadOnly(pParse, pTab) ){
  93     sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
  94     return 1;
  95   }
  96 #ifndef SQLITE_OMIT_VIEW
  97   if( !viewOk && IsView(pTab) ){
  98     sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
  99     return 1;
 100   }
 101 #endif
 102   return 0;
 103 }
 104
 105
 106 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
 107 /*
 108 ** Evaluate a view and store its result in an ephemeral table.  The
 109 ** pWhere argument is an optional WHERE clause that restricts the
 110 ** set of rows in the view that are to be added to the ephemeral table.
 111 */
 112 void sqlite3MaterializeView(
 113   Parse *pParse,       /* Parsing context */
 114   Table *pView,        /* View definition */
 115   Expr *pWhere,        /* Optional WHERE clause to be added */
 116   ExprList *pOrderBy,  /* Optional ORDER BY clause */
 117   Expr *pLimit,        /* Optional LIMIT clause */
 118   int iCur             /* Cursor number for ephemeral table */
 119 ){
 120   SelectDest dest;
 121   Select *pSel;
 122   SrcList *pFrom;
 123   sqlite3 *db = pParse->db;
 124   int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
 125   pWhere = sqlite3ExprDup(db, pWhere, 0);
 126   pFrom = sqlite3SrcListAppend(pParse, 0, 0, 0);
 127   if( pFrom ){
 128     assert( pFrom->nSrc==1 );
 129     pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
 130     pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
 131     assert( pFrom->a[0].fg.isUsing==0 );
 132     assert( pFrom->a[0].u3.pOn==0 );
 133   }
 134   pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, pOrderBy,
 135                           SF_IncludeHidden, pLimit);
 136   sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
 137   sqlite3Select(pParse, pSel, &dest);
 138   sqlite3SelectDelete(db, pSel);
 139 }
 140 #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
 141
 142 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
 143 /*
 144 ** Generate an expression tree to implement the WHERE, ORDER BY,
 145 ** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
 146 **
 147 **     DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
 148 **                            \__________________________/
 149 **                               pLimitWhere (pInClause)
 150 */
 151 Expr *sqlite3LimitWhere(
 152   Parse *pParse,               /* The parser context */
 153   SrcList *pSrc,               /* the FROM clause -- which tables to scan */
 154   Expr *pWhere,                /* The WHERE clause.  May be null */
 155   ExprList *pOrderBy,          /* The ORDER BY clause.  May be null */
 156   Expr *pLimit,                /* The LIMIT clause.  May be null */
 157   char *zStmtType              /* Either DELETE or UPDATE.  For err msgs. */
 158 ){
 159   sqlite3 *db = pParse->db;
 160   Expr *pLhs = NULL;           /* LHS of IN(SELECT...) operator */
 161   Expr *pInClause = NULL;      /* WHERE rowid IN ( select ) */
 162   ExprList *pEList = NULL;     /* Expression list contaning only pSelectRowid */
 163   SrcList *pSelectSrc = NULL;  /* SELECT rowid FROM x ... (dup of pSrc) */
 164   Select *pSelect = NULL;      /* Complete SELECT tree */
 165   Table *pTab;
 166
 167   /* Check that there isn't an ORDER BY without a LIMIT clause.
 168   */
 169   if( pOrderBy && pLimit==0 ) {
 170     sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
 171     sqlite3ExprDelete(pParse->db, pWhere);
 172     sqlite3ExprListDelete(pParse->db, pOrderBy);
 173     return 0;
 174   }
 175
 176   /* We only need to generate a select expression if there
 177   ** is a limit/offset term to enforce.
 178   */
 179   if( pLimit == 0 ) {
 180     return pWhere;
 181   }
 182
 183   /* Generate a select expression tree to enforce the limit/offset
 184   ** term for the DELETE or UPDATE statement.  For example:
 185   **   DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
 186   ** becomes:
 187   **   DELETE FROM table_a WHERE rowid IN (
 188   **     SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
 189   **   );
 190   */
 191
 192   pTab = pSrc->a[0].pTab;
 193   if( HasRowid(pTab) ){
 194     pLhs = sqlite3PExpr(pParse, TK_ROW, 0, 0);
 195     pEList = sqlite3ExprListAppend(
 196         pParse, 0, sqlite3PExpr(pParse, TK_ROW, 0, 0)
 197     );
 198   }else{
 199     Index *pPk = sqlite3PrimaryKeyIndex(pTab);
 200     if( pPk->nKeyCol==1 ){
 201       const char *zName = pTab->aCol[pPk->aiColumn[0]].zCnName;
 202       pLhs = sqlite3Expr(db, TK_ID, zName);
 203       pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, zName));
 204     }else{
 205       int i;
 206       for(i=0; i<pPk->nKeyCol; i++){
 207         Expr *p = sqlite3Expr(db, TK_ID, pTab->aCol[pPk->aiColumn[i]].zCnName);
 208         pEList = sqlite3ExprListAppend(pParse, pEList, p);
 209       }
 210       pLhs = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);
 211       if( pLhs ){
 212         pLhs->x.pList = sqlite3ExprListDup(db, pEList, 0);
 213       }
 214     }
 215   }
 216
 217   /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
 218   ** and the SELECT subtree. */
 219   pSrc->a[0].pTab = 0;
 220   pSelectSrc = sqlite3SrcListDup(db, pSrc, 0);
 221   pSrc->a[0].pTab = pTab;
 222   if( pSrc->a[0].fg.isIndexedBy ){
 223     assert( pSrc->a[0].fg.isCte==0 );
 224     pSrc->a[0].u2.pIBIndex = 0;
 225     pSrc->a[0].fg.isIndexedBy = 0;
 226     sqlite3DbFree(db, pSrc->a[0].u1.zIndexedBy);
 227   }else if( pSrc->a[0].fg.isCte ){
 228     pSrc->a[0].u2.pCteUse->nUse++;
 229   }
 230
 231   /* generate the SELECT expression tree. */
 232   pSelect = sqlite3SelectNew(pParse, pEList, pSelectSrc, pWhere, 0 ,0,
 233       pOrderBy,0,pLimit
 234   );
 235
 236   /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
 237   pInClause = sqlite3PExpr(pParse, TK_IN, pLhs, 0);
 238   sqlite3PExprAddSelect(pParse, pInClause, pSelect);
 239   return pInClause;
 240 }
 241 #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
 242        /*      && !defined(SQLITE_OMIT_SUBQUERY) */
 243
 244 /*
 245 ** Generate code for a DELETE FROM statement.
 246 **
 247 **     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
 248 **                 \________/       \________________/
 249 **                  pTabList              pWhere
 250 */
 251 void sqlite3DeleteFrom(
 252   Parse *pParse,         /* The parser context */
 253   SrcList *pTabList,     /* The table from which we should delete things */
 254   Expr *pWhere,          /* The WHERE clause.  May be null */
 255   ExprList *pOrderBy,    /* ORDER BY clause. May be null */
 256   Expr *pLimit           /* LIMIT clause. May be null */
 257 ){
 258   Vdbe *v;               /* The virtual database engine */
 259   Table *pTab;           /* The table from which records will be deleted */
 260   int i;                 /* Loop counter */
 261   WhereInfo *pWInfo;     /* Information about the WHERE clause */
 262   Index *pIdx;           /* For looping over indices of the table */
 263   int iTabCur;           /* Cursor number for the table */
 264   int iDataCur = 0;      /* VDBE cursor for the canonical data source */
 265   int iIdxCur = 0;       /* Cursor number of the first index */
 266   int nIdx;              /* Number of indices */
 267   sqlite3 *db;           /* Main database structure */
 268   AuthContext sContext;  /* Authorization context */
 269   NameContext sNC;       /* Name context to resolve expressions in */
 270   int iDb;               /* Database number */
 271   int memCnt = 0;        /* Memory cell used for change counting */
 272   int rcauth;            /* Value returned by authorization callback */
 273   int eOnePass;          /* ONEPASS_OFF or _SINGLE or _MULTI */
 274   int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
 275   u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */
 276   Index *pPk;            /* The PRIMARY KEY index on the table */
 277   int iPk = 0;           /* First of nPk registers holding PRIMARY KEY value */
 278   i16 nPk = 1;           /* Number of columns in the PRIMARY KEY */
 279   int iKey;              /* Memory cell holding key of row to be deleted */
 280   i16 nKey;              /* Number of memory cells in the row key */
 281   int iEphCur = 0;       /* Ephemeral table holding all primary key values */
 282   int iRowSet = 0;       /* Register for rowset of rows to delete */
 283   int addrBypass = 0;    /* Address of jump over the delete logic */
 284   int addrLoop = 0;      /* Top of the delete loop */
 285   int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */
 286   int bComplex;          /* True if there are triggers or FKs or
 287                          ** subqueries in the WHERE clause */
 288
 289 #ifndef SQLITE_OMIT_TRIGGER
 290   int isView;                  /* True if attempting to delete from a view */
 291   Trigger *pTrigger;           /* List of table triggers, if required */
 292 #endif
 293
 294   memset(&sContext, 0, sizeof(sContext));
 295   db = pParse->db;
 296   assert( db->pParse==pParse );
 297   if( pParse->nErr ){
 298     goto delete_from_cleanup;
 299   }
 300   assert( db->mallocFailed==0 );
 301   assert( pTabList->nSrc==1 );
 302
 303   /* Locate the table which we want to delete.  This table has to be
 304   ** put in an SrcList structure because some of the subroutines we
 305   ** will be calling are designed to work with multiple tables and expect
 306   ** an SrcList* parameter instead of just a Table* parameter.
 307   */
 308   pTab = sqlite3SrcListLookup(pParse, pTabList);
 309   if( pTab==0 )  goto delete_from_cleanup;
 310
 311   /* Figure out if we have any triggers and if the table being
 312   ** deleted from is a view
 313   */
 314 #ifndef SQLITE_OMIT_TRIGGER
 315   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
 316   isView = IsView(pTab);
 317 #else
 318 # define pTrigger 0
 319 # define isView 0
 320 #endif
 321   bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
 322 #ifdef SQLITE_OMIT_VIEW
 323 # undef isView
 324 # define isView 0
 325 #endif
 326
 327 #if TREETRACE_ENABLED
 328   if( sqlite3TreeTrace & 0x10000 ){
 329     sqlite3TreeViewLine(0, "In sqlite3Delete() at %s:%d", __FILE__, __LINE__);
 330     sqlite3TreeViewDelete(pParse->pWith, pTabList, pWhere,
 331                           pOrderBy, pLimit, pTrigger);
 332   }
 333 #endif
 334
 335 #ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
 336   if( !isView ){
 337     pWhere = sqlite3LimitWhere(
 338         pParse, pTabList, pWhere, pOrderBy, pLimit, "DELETE"
 339     );
 340     pOrderBy = 0;
 341     pLimit = 0;
 342   }
 343 #endif
 344
 345   /* If pTab is really a view, make sure it has been initialized.
 346   */
 347   if( sqlite3ViewGetColumnNames(pParse, pTab) ){
 348     goto delete_from_cleanup;
 349   }
 350
 351   if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
 352     goto delete_from_cleanup;
 353   }
 354   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
 355   assert( iDb<db->nDb );
 356   rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0,
 357                             db->aDb[iDb].zDbSName);
 358   assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
 359   if( rcauth==SQLITE_DENY ){
 360     goto delete_from_cleanup;
 361   }
 362   assert(!isView || pTrigger);
 363
 364   /* Assign cursor numbers to the table and all its indices.
 365   */
 366   assert( pTabList->nSrc==1 );
 367   iTabCur = pTabList->a[0].iCursor = pParse->nTab++;
 368   for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
 369     pParse->nTab++;
 370   }
 371
 372   /* Start the view context
 373   */
 374   if( isView ){
 375     sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
 376   }
 377
 378   /* Begin generating code.
 379   */
 380   v = sqlite3GetVdbe(pParse);
 381   if( v==0 ){
 382     goto delete_from_cleanup;
 383   }
 384   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
 385   sqlite3BeginWriteOperation(pParse, bComplex, iDb);
 386
 387   /* If we are trying to delete from a view, realize that view into
 388   ** an ephemeral table.
 389   */
 390 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
 391   if( isView ){
 392     sqlite3MaterializeView(pParse, pTab,
 393         pWhere, pOrderBy, pLimit, iTabCur
 394     );
 395     iDataCur = iIdxCur = iTabCur;
 396     pOrderBy = 0;
 397     pLimit = 0;
 398   }
 399 #endif
 400
 401   /* Resolve the column names in the WHERE clause.
 402   */
 403   memset(&sNC, 0, sizeof(sNC));
 404   sNC.pParse = pParse;
 405   sNC.pSrcList = pTabList;
 406   if( sqlite3ResolveExprNames(&sNC, pWhere) ){
 407     goto delete_from_cleanup;
 408   }
 409
 410   /* Initialize the counter of the number of rows deleted, if
 411   ** we are counting rows.
 412   */
 413   if( (db->flags & SQLITE_CountRows)!=0
 414    && !pParse->nested
 415    && !pParse->pTriggerTab
 416    && !pParse->bReturning
 417   ){
 418     memCnt = ++pParse->nMem;
 419     sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
 420   }
 421
 422 #ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
 423   /* Special case: A DELETE without a WHERE clause deletes everything.
 424   ** It is easier just to erase the whole table. Prior to version 3.6.5,
 425   ** this optimization caused the row change count (the value returned by
 426   ** API function sqlite3_count_changes) to be set incorrectly.
 427   **
 428   ** The "rcauth==SQLITE_OK" terms is the
 429   ** IMPLEMENTATION-OF: R-17228-37124 If the action code is SQLITE_DELETE and
 430   ** the callback returns SQLITE_IGNORE then the DELETE operation proceeds but
 431   ** the truncate optimization is disabled and all rows are deleted
 432   ** individually.
 433   */
 434   if( rcauth==SQLITE_OK
 435    && pWhere==0
 436    && !bComplex
 437    && !IsVirtual(pTab)
 438 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
 439    && db->xPreUpdateCallback==0
 440 #endif
 441   ){
 442     assert( !isView );
 443     sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
 444     if( HasRowid(pTab) ){
 445       sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt ? memCnt : -1,
 446                         pTab->zName, P4_STATIC);
 447     }
 448     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
 449       assert( pIdx->pSchema==pTab->pSchema );
 450       sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
 451       if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
 452         sqlite3VdbeChangeP3(v, -1, memCnt ? memCnt : -1);
 453       }
 454     }
 455   }else
 456 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
 457   {
 458     u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
 459     if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;
 460     wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
 461     if( HasRowid(pTab) ){
 462       /* For a rowid table, initialize the RowSet to an empty set */
 463       pPk = 0;
 464       nPk = 1;
 465       iRowSet = ++pParse->nMem;
 466       sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
 467     }else{
 468       /* For a WITHOUT ROWID table, create an ephemeral table used to
 469       ** hold all primary keys for rows to be deleted. */
 470       pPk = sqlite3PrimaryKeyIndex(pTab);
 471       assert( pPk!=0 );
 472       nPk = pPk->nKeyCol;
 473       iPk = pParse->nMem+1;
 474       pParse->nMem += nPk;
 475       iEphCur = pParse->nTab++;
 476       addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
 477       sqlite3VdbeSetP4KeyInfo(pParse, pPk);
 478     }
 479
 480     /* Construct a query to find the rowid or primary key for every row
 481     ** to be deleted, based on the WHERE clause. Set variable eOnePass
 482     ** to indicate the strategy used to implement this delete:
 483     **
 484     **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
 485     **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
 486     **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
 487     */
 488     pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0,0,wcf,iTabCur+1);
 489     if( pWInfo==0 ) goto delete_from_cleanup;
 490     eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
 491     assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
 492     assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
 493     if( eOnePass!=ONEPASS_SINGLE ) sqlite3MultiWrite(pParse);
 494     if( sqlite3WhereUsesDeferredSeek(pWInfo) ){
 495       sqlite3VdbeAddOp1(v, OP_FinishSeek, iTabCur);
 496     }
 497
 498     /* Keep track of the number of rows to be deleted */
 499     if( memCnt ){
 500       sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
 501     }
 502
 503     /* Extract the rowid or primary key for the current row */
 504     if( pPk ){
 505       for(i=0; i<nPk; i++){
 506         assert( pPk->aiColumn[i]>=0 );
 507         sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
 508                                         pPk->aiColumn[i], iPk+i);
 509       }
 510       iKey = iPk;
 511     }else{
 512       iKey = ++pParse->nMem;
 513       sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, -1, iKey);
 514     }
 515
 516     if( eOnePass!=ONEPASS_OFF ){
 517       /* For ONEPASS, no need to store the rowid/primary-key. There is only
 518       ** one, so just keep it in its register(s) and fall through to the
 519       ** delete code.  */
 520       nKey = nPk; /* OP_Found will use an unpacked key */
 521       aToOpen = sqlite3DbMallocRawNN(db, nIdx+2);
 522       if( aToOpen==0 ){
 523         sqlite3WhereEnd(pWInfo);
 524         goto delete_from_cleanup;
 525       }
 526       memset(aToOpen, 1, nIdx+1);
 527       aToOpen[nIdx+1] = 0;
 528       if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
 529       if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
 530       if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
 531       addrBypass = sqlite3VdbeMakeLabel(pParse);
 532     }else{
 533       if( pPk ){
 534         /* Add the PK key for this row to the temporary table */
 535         iKey = ++pParse->nMem;
 536         nKey = 0;   /* Zero tells OP_Found to use a composite key */
 537         sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
 538             sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
 539         sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEphCur, iKey, iPk, nPk);
 540       }else{
 541         /* Add the rowid of the row to be deleted to the RowSet */
 542         nKey = 1;  /* OP_DeferredSeek always uses a single rowid */
 543         sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
 544       }
 545       sqlite3WhereEnd(pWInfo);
 546     }
 547
 548     /* Unless this is a view, open cursors for the table we are
 549     ** deleting from and all its indices. If this is a view, then the
 550     ** only effect this statement has is to fire the INSTEAD OF
 551     ** triggers.
 552     */
 553     if( !isView ){
 554       int iAddrOnce = 0;
 555       if( eOnePass==ONEPASS_MULTI ){
 556         iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
 557       }
 558       testcase( IsVirtual(pTab) );
 559       sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,
 560                                  iTabCur, aToOpen, &iDataCur, &iIdxCur);
 561       assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
 562       assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
 563       if( eOnePass==ONEPASS_MULTI ){
 564         sqlite3VdbeJumpHereOrPopInst(v, iAddrOnce);
 565       }
 566     }
 567
 568     /* Set up a loop over the rowids/primary-keys that were found in the
 569     ** where-clause loop above.
 570     */
 571     if( eOnePass!=ONEPASS_OFF ){
 572       assert( nKey==nPk );  /* OP_Found will use an unpacked key */
 573       if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
 574         assert( pPk!=0 || IsView(pTab) );
 575         sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
 576         VdbeCoverage(v);
 577       }
 578     }else if( pPk ){
 579       addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
 580       if( IsVirtual(pTab) ){
 581         sqlite3VdbeAddOp3(v, OP_Column, iEphCur, 0, iKey);
 582       }else{
 583         sqlite3VdbeAddOp2(v, OP_RowData, iEphCur, iKey);
 584       }
 585       assert( nKey==0 );  /* OP_Found will use a composite key */
 586     }else{
 587       addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);
 588       VdbeCoverage(v);
 589       assert( nKey==1 );
 590     }
 591
 592     /* Delete the row */
 593 #ifndef SQLITE_OMIT_VIRTUALTABLE
 594     if( IsVirtual(pTab) ){
 595       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
 596       sqlite3VtabMakeWritable(pParse, pTab);
 597       assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
 598       sqlite3MayAbort(pParse);
 599       if( eOnePass==ONEPASS_SINGLE ){
 600         sqlite3VdbeAddOp1(v, OP_Close, iTabCur);
 601         if( sqlite3IsToplevel(pParse) ){
 602           pParse->isMultiWrite = 0;
 603         }
 604       }
 605       sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
 606       sqlite3VdbeChangeP5(v, OE_Abort);
 607     }else
 608 #endif
 609     {
 610       int count = (pParse->nested==0);    /* True to count changes */
 611       sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
 612           iKey, nKey, count, OE_Default, eOnePass, aiCurOnePass[1]);
 613     }
 614
 615     /* End of the loop over all rowids/primary-keys. */
 616     if( eOnePass!=ONEPASS_OFF ){
 617       sqlite3VdbeResolveLabel(v, addrBypass);
 618       sqlite3WhereEnd(pWInfo);
 619     }else if( pPk ){
 620       sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
 621       sqlite3VdbeJumpHere(v, addrLoop);
 622     }else{
 623       sqlite3VdbeGoto(v, addrLoop);
 624       sqlite3VdbeJumpHere(v, addrLoop);
 625     }
 626   } /* End non-truncate path */
 627
 628   /* Update the sqlite_sequence table by storing the content of the
 629   ** maximum rowid counter values recorded while inserting into
 630   ** autoincrement tables.
 631   */
 632   if( pParse->nested==0 && pParse->pTriggerTab==0 ){
 633     sqlite3AutoincrementEnd(pParse);
 634   }
 635
 636   /* Return the number of rows that were deleted. If this routine is
 637   ** generating code because of a call to sqlite3NestedParse(), do not
 638   ** invoke the callback function.
 639   */
 640   if( memCnt ){
 641     sqlite3CodeChangeCount(v, memCnt, "rows deleted");
 642   }
 643
 644 delete_from_cleanup:
 645   sqlite3AuthContextPop(&sContext);
 646   sqlite3SrcListDelete(db, pTabList);
 647   sqlite3ExprDelete(db, pWhere);
 648 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
 649   sqlite3ExprListDelete(db, pOrderBy);
 650   sqlite3ExprDelete(db, pLimit);
 651 #endif
 652   sqlite3DbFree(db, aToOpen);
 653   return;
 654 }
 655 /* Make sure "isView" and other macros defined above are undefined. Otherwise
 656 ** they may interfere with compilation of other functions in this file
 657 ** (or in another file, if this file becomes part of the amalgamation).  */
 658 #ifdef isView
 659  #undef isView
 660 #endif
 661 #ifdef pTrigger
 662  #undef pTrigger
 663 #endif
 664
 665 /*
 666 ** This routine generates VDBE code that causes a single row of a
 667 ** single table to be deleted.  Both the original table entry and
 668 ** all indices are removed.
 669 **
 670 ** Preconditions:
 671 **
 672 **   1.  iDataCur is an open cursor on the btree that is the canonical data
 673 **       store for the table.  (This will be either the table itself,
 674 **       in the case of a rowid table, or the PRIMARY KEY index in the case
 675 **       of a WITHOUT ROWID table.)
 676 **
 677 **   2.  Read/write cursors for all indices of pTab must be open as
 678 **       cursor number iIdxCur+i for the i-th index.
 679 **
 680 **   3.  The primary key for the row to be deleted must be stored in a
 681 **       sequence of nPk memory cells starting at iPk.  If nPk==0 that means
 682 **       that a search record formed from OP_MakeRecord is contained in the
 683 **       single memory location iPk.
 684 **
 685 ** eMode:
 686 **   Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or
 687 **   ONEPASS_MULTI.  If eMode is not ONEPASS_OFF, then the cursor
 688 **   iDataCur already points to the row to delete. If eMode is ONEPASS_OFF
 689 **   then this function must seek iDataCur to the entry identified by iPk
 690 **   and nPk before reading from it.
 691 **
 692 **   If eMode is ONEPASS_MULTI, then this call is being made as part
 693 **   of a ONEPASS delete that affects multiple rows. In this case, if
 694 **   iIdxNoSeek is a valid cursor number (>=0) and is not the same as
 695 **   iDataCur, then its position should be preserved following the delete
 696 **   operation. Or, if iIdxNoSeek is not a valid cursor number, the
 697 **   position of iDataCur should be preserved instead.
 698 **
 699 ** iIdxNoSeek:
 700 **   If iIdxNoSeek is a valid cursor number (>=0) not equal to iDataCur,
 701 **   then it identifies an index cursor (from within array of cursors
 702 **   starting at iIdxCur) that already points to the index entry to be deleted.
 703 **   Except, this optimization is disabled if there are BEFORE triggers since
 704 **   the trigger body might have moved the cursor.
 705 */
 706 void sqlite3GenerateRowDelete(
 707   Parse *pParse,     /* Parsing context */
 708   Table *pTab,       /* Table containing the row to be deleted */
 709   Trigger *pTrigger, /* List of triggers to (potentially) fire */
 710   int iDataCur,      /* Cursor from which column data is extracted */
 711   int iIdxCur,       /* First index cursor */
 712   int iPk,           /* First memory cell containing the PRIMARY KEY */
 713   i16 nPk,           /* Number of PRIMARY KEY memory cells */
 714   u8 count,          /* If non-zero, increment the row change counter */
 715   u8 onconf,         /* Default ON CONFLICT policy for triggers */
 716   u8 eMode,          /* ONEPASS_OFF, _SINGLE, or _MULTI.  See above */
 717   int iIdxNoSeek     /* Cursor number of cursor that does not need seeking */
 718 ){
 719   Vdbe *v = pParse->pVdbe;        /* Vdbe */
 720   int iOld = 0;                   /* First register in OLD.* array */
 721   int iLabel;                     /* Label resolved to end of generated code */
 722   u8 opSeek;                      /* Seek opcode */
 723
 724   /* Vdbe is guaranteed to have been allocated by this stage. */
 725   assert( v );
 726   VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",
 727                          iDataCur, iIdxCur, iPk, (int)nPk));
 728
 729   /* Seek cursor iCur to the row to delete. If this row no longer exists
 730   ** (this can happen if a trigger program has already deleted it), do
 731   ** not attempt to delete it or fire any DELETE triggers.  */
 732   iLabel = sqlite3VdbeMakeLabel(pParse);
 733   opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
 734   if( eMode==ONEPASS_OFF ){
 735     sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
 736     VdbeCoverageIf(v, opSeek==OP_NotExists);
 737     VdbeCoverageIf(v, opSeek==OP_NotFound);
 738   }
 739
 740   /* If there are any triggers to fire, allocate a range of registers to
 741   ** use for the old.* references in the triggers.  */
 742   if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){
 743     u32 mask;                     /* Mask of OLD.* columns in use */
 744     int iCol;                     /* Iterator used while populating OLD.* */
 745     int addrStart;                /* Start of BEFORE trigger programs */
 746
 747     /* TODO: Could use temporary registers here. Also could attempt to
 748     ** avoid copying the contents of the rowid register.  */
 749     mask = sqlite3TriggerColmask(
 750         pParse, pTrigger, 0, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onconf
 751     );
 752     mask |= sqlite3FkOldmask(pParse, pTab);
 753     iOld = pParse->nMem+1;
 754     pParse->nMem += (1 + pTab->nCol);
 755
 756     /* Populate the OLD.* pseudo-table register array. These values will be
 757     ** used by any BEFORE and AFTER triggers that exist.  */
 758     sqlite3VdbeAddOp2(v, OP_Copy, iPk, iOld);
 759     for(iCol=0; iCol<pTab->nCol; iCol++){
 760       testcase( mask!=0xffffffff && iCol==31 );
 761       testcase( mask!=0xffffffff && iCol==32 );
 762       if( mask==0xffffffff || (iCol<=31 && (mask & MASKBIT32(iCol))!=0) ){
 763         int kk = sqlite3TableColumnToStorage(pTab, iCol);
 764         sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+kk+1);
 765       }
 766     }
 767
 768     /* Invoke BEFORE DELETE trigger programs. */
 769     addrStart = sqlite3VdbeCurrentAddr(v);
 770     sqlite3CodeRowTrigger(pParse, pTrigger,
 771         TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel
 772     );
 773
 774     /* If any BEFORE triggers were coded, then seek the cursor to the
 775     ** row to be deleted again. It may be that the BEFORE triggers moved
 776     ** the cursor or already deleted the row that the cursor was
 777     ** pointing to.
 778     **
 779     ** Also disable the iIdxNoSeek optimization since the BEFORE trigger
 780     ** may have moved that cursor.
 781     */
 782     if( addrStart<sqlite3VdbeCurrentAddr(v) ){
 783       sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
 784       VdbeCoverageIf(v, opSeek==OP_NotExists);
 785       VdbeCoverageIf(v, opSeek==OP_NotFound);
 786       testcase( iIdxNoSeek>=0 );
 787       iIdxNoSeek = -1;
 788     }
 789
 790     /* Do FK processing. This call checks that any FK constraints that
 791     ** refer to this table (i.e. constraints attached to other tables)
 792     ** are not violated by deleting this row.  */
 793     sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
 794   }
 795
 796   /* Delete the index and table entries. Skip this step if pTab is really
 797   ** a view (in which case the only effect of the DELETE statement is to
 798   ** fire the INSTEAD OF triggers).
 799   **
 800   ** If variable 'count' is non-zero, then this OP_Delete instruction should
 801   ** invoke the update-hook. The pre-update-hook, on the other hand should
 802   ** be invoked unless table pTab is a system table. The difference is that
 803   ** the update-hook is not invoked for rows removed by REPLACE, but the
 804   ** pre-update-hook is.
 805   */
 806   if( !IsView(pTab) ){
 807     u8 p5 = 0;
 808     sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
 809     sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
 810     if( pParse->nested==0 || 0==sqlite3_stricmp(pTab->zName, "sqlite_stat1") ){
 811       sqlite3VdbeAppendP4(v, (char*)pTab, P4_TABLE);
 812     }
 813     if( eMode!=ONEPASS_OFF ){
 814       sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE);
 815     }
 816     if( iIdxNoSeek>=0 && iIdxNoSeek!=iDataCur ){
 817       sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
 818     }
 819     if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION;
 820     sqlite3VdbeChangeP5(v, p5);
 821   }
 822
 823   /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
 824   ** handle rows (possibly in other tables) that refer via a foreign key
 825   ** to the row just deleted. */
 826   sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);
 827
 828   /* Invoke AFTER DELETE trigger programs. */
 829   sqlite3CodeRowTrigger(pParse, pTrigger,
 830       TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel
 831   );
 832
 833   /* Jump here if the row had already been deleted before any BEFORE
 834   ** trigger programs were invoked. Or if a trigger program throws a
 835   ** RAISE(IGNORE) exception.  */
 836   sqlite3VdbeResolveLabel(v, iLabel);
 837   VdbeModuleComment((v, "END: GenRowDel()"));
 838 }
 839
 840 /*
 841 ** This routine generates VDBE code that causes the deletion of all
 842 ** index entries associated with a single row of a single table, pTab
 843 **
 844 ** Preconditions:
 845 **
 846 **   1.  A read/write cursor "iDataCur" must be open on the canonical storage
 847 **       btree for the table pTab.  (This will be either the table itself
 848 **       for rowid tables or to the primary key index for WITHOUT ROWID
 849 **       tables.)
 850 **
 851 **   2.  Read/write cursors for all indices of pTab must be open as
 852 **       cursor number iIdxCur+i for the i-th index.  (The pTab->pIndex
 853 **       index is the 0-th index.)
 854 **
 855 **   3.  The "iDataCur" cursor must be already be positioned on the row
 856 **       that is to be deleted.
 857 */
 858 void sqlite3GenerateRowIndexDelete(
 859   Parse *pParse,     /* Parsing and code generating context */
 860   Table *pTab,       /* Table containing the row to be deleted */
 861   int iDataCur,      /* Cursor of table holding data. */
 862   int iIdxCur,       /* First index cursor */
 863   int *aRegIdx,      /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
 864   int iIdxNoSeek     /* Do not delete from this cursor */
 865 ){
 866   int i;             /* Index loop counter */
 867   int r1 = -1;       /* Register holding an index key */
 868   int iPartIdxLabel; /* Jump destination for skipping partial index entries */
 869   Index *pIdx;       /* Current index */
 870   Index *pPrior = 0; /* Prior index */
 871   Vdbe *v;           /* The prepared statement under construction */
 872   Index *pPk;        /* PRIMARY KEY index, or NULL for rowid tables */
 873
 874   v = pParse->pVdbe;
 875   pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
 876   for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
 877     assert( iIdxCur+i!=iDataCur || pPk==pIdx );
 878     if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
 879     if( pIdx==pPk ) continue;
 880     if( iIdxCur+i==iIdxNoSeek ) continue;
 881     VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
 882     r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
 883         &iPartIdxLabel, pPrior, r1);
 884     sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
 885         pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
 886     sqlite3VdbeChangeP5(v, 1);  /* Cause IdxDelete to error if no entry found */
 887     sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
 888     pPrior = pIdx;
 889   }
 890 }
 891
 892 /*
 893 ** Generate code that will assemble an index key and stores it in register
 894 ** regOut.  The key with be for index pIdx which is an index on pTab.
 895 ** iCur is the index of a cursor open on the pTab table and pointing to
 896 ** the entry that needs indexing.  If pTab is a WITHOUT ROWID table, then
 897 ** iCur must be the cursor of the PRIMARY KEY index.
 898 **
 899 ** Return a register number which is the first in a block of
 900 ** registers that holds the elements of the index key.  The
 901 ** block of registers has already been deallocated by the time
 902 ** this routine returns.
 903 **
 904 ** If *piPartIdxLabel is not NULL, fill it in with a label and jump
 905 ** to that label if pIdx is a partial index that should be skipped.
 906 ** The label should be resolved using sqlite3ResolvePartIdxLabel().
 907 ** A partial index should be skipped if its WHERE clause evaluates
 908 ** to false or null.  If pIdx is not a partial index, *piPartIdxLabel
 909 ** will be set to zero which is an empty label that is ignored by
 910 ** sqlite3ResolvePartIdxLabel().
 911 **
 912 ** The pPrior and regPrior parameters are used to implement a cache to
 913 ** avoid unnecessary register loads.  If pPrior is not NULL, then it is
 914 ** a pointer to a different index for which an index key has just been
 915 ** computed into register regPrior.  If the current pIdx index is generating
 916 ** its key into the same sequence of registers and if pPrior and pIdx share
 917 ** a column in common, then the register corresponding to that column already
 918 ** holds the correct value and the loading of that register is skipped.
 919 ** This optimization is helpful when doing a DELETE or an INTEGRITY_CHECK
 920 ** on a table with multiple indices, and especially with the ROWID or
 921 ** PRIMARY KEY columns of the index.
 922 */
 923 int sqlite3GenerateIndexKey(
 924   Parse *pParse,       /* Parsing context */
 925   Index *pIdx,         /* The index for which to generate a key */
 926   int iDataCur,        /* Cursor number from which to take column data */
 927   int regOut,          /* Put the new key into this register if not 0 */
 928   int prefixOnly,      /* Compute only a unique prefix of the key */
 929   int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */
 930   Index *pPrior,       /* Previously generated index key */
 931   int regPrior         /* Register holding previous generated key */
 932 ){
 933   Vdbe *v = pParse->pVdbe;
 934   int j;
 935   int regBase;
 936   int nCol;
 937
 938   if( piPartIdxLabel ){
 939     if( pIdx->pPartIdxWhere ){
 940       *piPartIdxLabel = sqlite3VdbeMakeLabel(pParse);
 941       pParse->iSelfTab = iDataCur + 1;
 942       sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel,
 943                             SQLITE_JUMPIFNULL);
 944       pParse->iSelfTab = 0;
 945       pPrior = 0; /* Ticket a9efb42811fa41ee 2019-11-02;
 946                   ** pPartIdxWhere may have corrupted regPrior registers */
 947     }else{
 948       *piPartIdxLabel = 0;
 949     }
 950   }
 951   nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
 952   regBase = sqlite3GetTempRange(pParse, nCol);
 953   if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
 954   for(j=0; j<nCol; j++){
 955     if( pPrior
 956      && pPrior->aiColumn[j]==pIdx->aiColumn[j]
 957      && pPrior->aiColumn[j]!=XN_EXPR
 958     ){
 959       /* This column was already computed by the previous index */
 960       continue;
 961     }
 962     sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
 963     if( pIdx->aiColumn[j]>=0 ){
 964       /* If the column affinity is REAL but the number is an integer, then it
 965       ** might be stored in the table as an integer (using a compact
 966       ** representation) then converted to REAL by an OP_RealAffinity opcode.
 967       ** But we are getting ready to store this value back into an index, where
 968       ** it should be converted by to INTEGER again.  So omit the
 969       ** OP_RealAffinity opcode if it is present */
 970       sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity);
 971     }
 972   }
 973   if( regOut ){
 974     sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);
 975   }
 976   sqlite3ReleaseTempRange(pParse, regBase, nCol);
 977   return regBase;
 978 }
 979
 980 /*
 981 ** If a prior call to sqlite3GenerateIndexKey() generated a jump-over label
 982 ** because it was a partial index, then this routine should be called to
 983 ** resolve that label.
 984 */
 985 void sqlite3ResolvePartIdxLabel(Parse *pParse, int iLabel){
 986   if( iLabel ){
 987     sqlite3VdbeResolveLabel(pParse->pVdbe, iLabel);
 988   }
 989 }