1 /* 2 ** 2008 August 18 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 ** 13 ** This file contains routines used for walking the parser tree and 14 ** resolve all identifiers by associating them with a particular 15 ** table and column. 16 */ 17 #include "sqliteInt.h" 18 19 /* 20 ** Magic table number to mean the EXCLUDED table in an UPSERT statement. 21 */ 22 #define EXCLUDED_TABLE_NUMBER 2 23 24 /* 25 ** Walk the expression tree pExpr and increase the aggregate function 26 ** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node. 27 ** This needs to occur when copying a TK_AGG_FUNCTION node from an 28 ** outer query into an inner subquery. 29 ** 30 ** incrAggFunctionDepth(pExpr,n) is the main routine. incrAggDepth(..) 31 ** is a helper function - a callback for the tree walker. 32 ** 33 ** See also the sqlite3WindowExtraAggFuncDepth() routine in window.c 34 */ 35 static int incrAggDepth(Walker *pWalker, Expr *pExpr){ 36 if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n; 37 return WRC_Continue; 38 } 39 static void incrAggFunctionDepth(Expr *pExpr, int N){ 40 if( N>0 ){ 41 Walker w; 42 memset(&w, 0, sizeof(w)); 43 w.xExprCallback = incrAggDepth; 44 w.u.n = N; 45 sqlite3WalkExpr(&w, pExpr); 46 } 47 } 48 49 /* 50 ** Turn the pExpr expression into an alias for the iCol-th column of the 51 ** result set in pEList. 52 ** 53 ** If the reference is followed by a COLLATE operator, then make sure 54 ** the COLLATE operator is preserved. For example: 55 ** 56 ** SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase; 57 ** 58 ** Should be transformed into: 59 ** 60 ** SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase; 61 ** 62 ** The nSubquery parameter specifies how many levels of subquery the 63 ** alias is removed from the original expression. The usual value is 64 ** zero but it might be more if the alias is contained within a subquery 65 ** of the original expression. The Expr.op2 field of TK_AGG_FUNCTION 66 ** structures must be increased by the nSubquery amount. 67 */ 68 static void resolveAlias( 69 Parse *pParse, /* Parsing context */ 70 ExprList *pEList, /* A result set */ 71 int iCol, /* A column in the result set. 0..pEList->nExpr-1 */ 72 Expr *pExpr, /* Transform this into an alias to the result set */ 73 int nSubquery /* Number of subqueries that the label is moving */ 74 ){ 75 Expr *pOrig; /* The iCol-th column of the result set */ 76 Expr *pDup; /* Copy of pOrig */ 77 sqlite3 *db; /* The database connection */ 78 79 assert( iCol>=0 && iCol<pEList->nExpr ); 80 pOrig = pEList->a[iCol].pExpr; 81 assert( pOrig!=0 ); 82 db = pParse->db; 83 pDup = sqlite3ExprDup(db, pOrig, 0); 84 if( db->mallocFailed ){ 85 sqlite3ExprDelete(db, pDup); 86 pDup = 0; 87 }else{ 88 incrAggFunctionDepth(pDup, nSubquery); 89 if( pExpr->op==TK_COLLATE ){ 90 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 91 pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken); 92 } 93 94 /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 95 ** prevents ExprDelete() from deleting the Expr structure itself, 96 ** allowing it to be repopulated by the memcpy() on the following line. 97 ** The pExpr->u.zToken might point into memory that will be freed by the 98 ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to 99 ** make a copy of the token before doing the sqlite3DbFree(). 100 */ 101 ExprSetProperty(pExpr, EP_Static); 102 sqlite3ExprDelete(db, pExpr); 103 memcpy(pExpr, pDup, sizeof(*pExpr)); 104 if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){ 105 assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 ); 106 pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken); 107 pExpr->flags |= EP_MemToken; 108 } 109 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 110 if( ALWAYS(pExpr->y.pWin!=0) ){ 111 pExpr->y.pWin->pOwner = pExpr; 112 } 113 } 114 sqlite3DbFree(db, pDup); 115 } 116 } 117 118 119 /* 120 ** Return TRUE if the name zCol occurs anywhere in the USING clause. 121 ** 122 ** Return FALSE if the USING clause is NULL or if it does not contain 123 ** zCol. 124 */ 125 static int nameInUsingClause(IdList *pUsing, const char *zCol){ 126 if( pUsing ){ 127 int k; 128 for(k=0; k<pUsing->nId; k++){ 129 if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ) return 1; 130 } 131 } 132 return 0; 133 } 134 135 /* 136 ** Subqueries stores the original database, table and column names for their 137 ** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN". 138 ** Check to see if the zSpan given to this routine matches the zDb, zTab, 139 ** and zCol. If any of zDb, zTab, and zCol are NULL then those fields will 140 ** match anything. 141 */ 142 int sqlite3MatchEName( 143 const struct ExprList_item *pItem, 144 const char *zCol, 145 const char *zTab, 146 const char *zDb 147 ){ 148 int n; 149 const char *zSpan; 150 if( pItem->eEName!=ENAME_TAB ) return 0; 151 zSpan = pItem->zEName; 152 for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} 153 if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){ 154 return 0; 155 } 156 zSpan += n+1; 157 for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} 158 if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){ 159 return 0; 160 } 161 zSpan += n+1; 162 if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){ 163 return 0; 164 } 165 return 1; 166 } 167 168 /* 169 ** Return TRUE if the double-quoted string mis-feature should be supported. 170 */ 171 static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){ 172 if( db->init.busy ) return 1; /* Always support for legacy schemas */ 173 if( pTopNC->ncFlags & NC_IsDDL ){ 174 /* Currently parsing a DDL statement */ 175 if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){ 176 return 1; 177 } 178 return (db->flags & SQLITE_DqsDDL)!=0; 179 }else{ 180 /* Currently parsing a DML statement */ 181 return (db->flags & SQLITE_DqsDML)!=0; 182 } 183 } 184 185 /* 186 ** The argument is guaranteed to be a non-NULL Expr node of type TK_COLUMN. 187 ** return the appropriate colUsed mask. 188 */ 189 Bitmask sqlite3ExprColUsed(Expr *pExpr){ 190 int n; 191 Table *pExTab; 192 193 n = pExpr->iColumn; 194 assert( ExprUseYTab(pExpr) ); 195 pExTab = pExpr->y.pTab; 196 assert( pExTab!=0 ); 197 if( (pExTab->tabFlags & TF_HasGenerated)!=0 198 && (pExTab->aCol[n].colFlags & COLFLAG_GENERATED)!=0 199 ){ 200 testcase( pExTab->nCol==BMS-1 ); 201 testcase( pExTab->nCol==BMS ); 202 return pExTab->nCol>=BMS ? ALLBITS : MASKBIT(pExTab->nCol)-1; 203 }else{ 204 testcase( n==BMS-1 ); 205 testcase( n==BMS ); 206 if( n>=BMS ) n = BMS-1; 207 return ((Bitmask)1)<<n; 208 } 209 } 210 211 /* 212 ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up 213 ** that name in the set of source tables in pSrcList and make the pExpr 214 ** expression node refer back to that source column. The following changes 215 ** are made to pExpr: 216 ** 217 ** pExpr->iDb Set the index in db->aDb[] of the database X 218 ** (even if X is implied). 219 ** pExpr->iTable Set to the cursor number for the table obtained 220 ** from pSrcList. 221 ** pExpr->y.pTab Points to the Table structure of X.Y (even if 222 ** X and/or Y are implied.) 223 ** pExpr->iColumn Set to the column number within the table. 224 ** pExpr->op Set to TK_COLUMN. 225 ** pExpr->pLeft Any expression this points to is deleted 226 ** pExpr->pRight Any expression this points to is deleted. 227 ** 228 ** The zDb variable is the name of the database (the "X"). This value may be 229 ** NULL meaning that name is of the form Y.Z or Z. Any available database 230 ** can be used. The zTable variable is the name of the table (the "Y"). This 231 ** value can be NULL if zDb is also NULL. If zTable is NULL it 232 ** means that the form of the name is Z and that columns from any table 233 ** can be used. 234 ** 235 ** If the name cannot be resolved unambiguously, leave an error message 236 ** in pParse and return WRC_Abort. Return WRC_Prune on success. 237 */ 238 static int lookupName( 239 Parse *pParse, /* The parsing context */ 240 const char *zDb, /* Name of the database containing table, or NULL */ 241 const char *zTab, /* Name of table containing column, or NULL */ 242 const char *zCol, /* Name of the column. */ 243 NameContext *pNC, /* The name context used to resolve the name */ 244 Expr *pExpr /* Make this EXPR node point to the selected column */ 245 ){ 246 int i, j; /* Loop counters */ 247 int cnt = 0; /* Number of matching column names */ 248 int cntTab = 0; /* Number of matching table names */ 249 int nSubquery = 0; /* How many levels of subquery */ 250 sqlite3 *db = pParse->db; /* The database connection */ 251 SrcItem *pItem; /* Use for looping over pSrcList items */ 252 SrcItem *pMatch = 0; /* The matching pSrcList item */ 253 NameContext *pTopNC = pNC; /* First namecontext in the list */ 254 Schema *pSchema = 0; /* Schema of the expression */ 255 int eNewExprOp = TK_COLUMN; /* New value for pExpr->op on success */ 256 Table *pTab = 0; /* Table hold the row */ 257 Column *pCol; /* A column of pTab */ 258 259 assert( pNC ); /* the name context cannot be NULL. */ 260 assert( zCol ); /* The Z in X.Y.Z cannot be NULL */ 261 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) ); 262 263 /* Initialize the node to no-match */ 264 pExpr->iTable = -1; 265 ExprSetVVAProperty(pExpr, EP_NoReduce); 266 267 /* Translate the schema name in zDb into a pointer to the corresponding 268 ** schema. If not found, pSchema will remain NULL and nothing will match 269 ** resulting in an appropriate error message toward the end of this routine 270 */ 271 if( zDb ){ 272 testcase( pNC->ncFlags & NC_PartIdx ); 273 testcase( pNC->ncFlags & NC_IsCheck ); 274 if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){ 275 /* Silently ignore database qualifiers inside CHECK constraints and 276 ** partial indices. Do not raise errors because that might break 277 ** legacy and because it does not hurt anything to just ignore the 278 ** database name. */ 279 zDb = 0; 280 }else{ 281 for(i=0; i<db->nDb; i++){ 282 assert( db->aDb[i].zDbSName ); 283 if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){ 284 pSchema = db->aDb[i].pSchema; 285 break; 286 } 287 } 288 if( i==db->nDb && sqlite3StrICmp("main", zDb)==0 ){ 289 /* This branch is taken when the main database has been renamed 290 ** using SQLITE_DBCONFIG_MAINDBNAME. */ 291 pSchema = db->aDb[0].pSchema; 292 zDb = db->aDb[0].zDbSName; 293 } 294 } 295 } 296 297 /* Start at the inner-most context and move outward until a match is found */ 298 assert( pNC && cnt==0 ); 299 do{ 300 ExprList *pEList; 301 SrcList *pSrcList = pNC->pSrcList; 302 303 if( pSrcList ){ 304 for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ 305 u8 hCol; 306 pTab = pItem->pTab; 307 assert( pTab!=0 && pTab->zName!=0 ); 308 assert( pTab->nCol>0 || pParse->nErr ); 309 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){ 310 int hit = 0; 311 pEList = pItem->pSelect->pEList; 312 for(j=0; j<pEList->nExpr; j++){ 313 if( sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){ 314 cnt++; 315 cntTab = 2; 316 pMatch = pItem; 317 pExpr->iColumn = j; 318 hit = 1; 319 } 320 } 321 if( hit || zTab==0 ) continue; 322 } 323 if( zDb ){ 324 if( pTab->pSchema!=pSchema ) continue; 325 if( pSchema==0 && strcmp(zDb,"*")!=0 ) continue; 326 } 327 if( zTab ){ 328 const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName; 329 assert( zTabName!=0 ); 330 if( sqlite3StrICmp(zTabName, zTab)!=0 ){ 331 continue; 332 } 333 assert( ExprUseYTab(pExpr) ); 334 if( IN_RENAME_OBJECT && pItem->zAlias ){ 335 sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab); 336 } 337 } 338 hCol = sqlite3StrIHash(zCol); 339 for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ 340 if( pCol->hName==hCol 341 && sqlite3StrICmp(pCol->zCnName, zCol)==0 342 ){ 343 /* If there has been exactly one prior match and this match 344 ** is for the right-hand table of a NATURAL JOIN or is in a 345 ** USING clause, then skip this match. 346 */ 347 if( cnt==1 ){ 348 if( pItem->fg.jointype & JT_NATURAL ) continue; 349 if( nameInUsingClause(pItem->pUsing, zCol) ) continue; 350 } 351 cnt++; 352 pMatch = pItem; 353 /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ 354 pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j; 355 break; 356 } 357 } 358 if( 0==cnt && VisibleRowid(pTab) ){ 359 cntTab++; 360 pMatch = pItem; 361 } 362 } 363 if( pMatch ){ 364 pExpr->iTable = pMatch->iCursor; 365 assert( ExprUseYTab(pExpr) ); 366 pExpr->y.pTab = pMatch->pTab; 367 /* RIGHT JOIN not (yet) supported */ 368 assert( (pMatch->fg.jointype & JT_RIGHT)==0 ); 369 if( (pMatch->fg.jointype & JT_LEFT)!=0 ){ 370 ExprSetProperty(pExpr, EP_CanBeNull); 371 } 372 pSchema = pExpr->y.pTab->pSchema; 373 } 374 } /* if( pSrcList ) */ 375 376 #if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) 377 /* If we have not already resolved the name, then maybe 378 ** it is a new.* or old.* trigger argument reference. Or 379 ** maybe it is an excluded.* from an upsert. Or maybe it is 380 ** a reference in the RETURNING clause to a table being modified. 381 */ 382 if( cnt==0 && zDb==0 ){ 383 pTab = 0; 384 #ifndef SQLITE_OMIT_TRIGGER 385 if( pParse->pTriggerTab!=0 ){ 386 int op = pParse->eTriggerOp; 387 assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT ); 388 if( pParse->bReturning ){ 389 if( (pNC->ncFlags & NC_UBaseReg)!=0 390 && (zTab==0 || sqlite3StrICmp(zTab,pParse->pTriggerTab->zName)==0) 391 ){ 392 pExpr->iTable = op!=TK_DELETE; 393 pTab = pParse->pTriggerTab; 394 } 395 }else if( op!=TK_DELETE && zTab && sqlite3StrICmp("new",zTab) == 0 ){ 396 pExpr->iTable = 1; 397 pTab = pParse->pTriggerTab; 398 }else if( op!=TK_INSERT && zTab && sqlite3StrICmp("old",zTab)==0 ){ 399 pExpr->iTable = 0; 400 pTab = pParse->pTriggerTab; 401 } 402 } 403 #endif /* SQLITE_OMIT_TRIGGER */ 404 #ifndef SQLITE_OMIT_UPSERT 405 if( (pNC->ncFlags & NC_UUpsert)!=0 && zTab!=0 ){ 406 Upsert *pUpsert = pNC->uNC.pUpsert; 407 if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){ 408 pTab = pUpsert->pUpsertSrc->a[0].pTab; 409 pExpr->iTable = EXCLUDED_TABLE_NUMBER; 410 } 411 } 412 #endif /* SQLITE_OMIT_UPSERT */ 413 414 if( pTab ){ 415 int iCol; 416 u8 hCol = sqlite3StrIHash(zCol); 417 pSchema = pTab->pSchema; 418 cntTab++; 419 for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){ 420 if( pCol->hName==hCol 421 && sqlite3StrICmp(pCol->zCnName, zCol)==0 422 ){ 423 if( iCol==pTab->iPKey ){ 424 iCol = -1; 425 } 426 break; 427 } 428 } 429 if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){ 430 /* IMP: R-51414-32910 */ 431 iCol = -1; 432 } 433 if( iCol<pTab->nCol ){ 434 cnt++; 435 pMatch = 0; 436 #ifndef SQLITE_OMIT_UPSERT 437 if( pExpr->iTable==EXCLUDED_TABLE_NUMBER ){ 438 testcase( iCol==(-1) ); 439 assert( ExprUseYTab(pExpr) ); 440 if( IN_RENAME_OBJECT ){ 441 pExpr->iColumn = iCol; 442 pExpr->y.pTab = pTab; 443 eNewExprOp = TK_COLUMN; 444 }else{ 445 pExpr->iTable = pNC->uNC.pUpsert->regData + 446 sqlite3TableColumnToStorage(pTab, iCol); 447 eNewExprOp = TK_REGISTER; 448 } 449 }else 450 #endif /* SQLITE_OMIT_UPSERT */ 451 { 452 assert( ExprUseYTab(pExpr) ); 453 pExpr->y.pTab = pTab; 454 if( pParse->bReturning ){ 455 eNewExprOp = TK_REGISTER; 456 pExpr->op2 = TK_COLUMN; 457 pExpr->iTable = pNC->uNC.iBaseReg + (pTab->nCol+1)*pExpr->iTable + 458 sqlite3TableColumnToStorage(pTab, iCol) + 1; 459 }else{ 460 pExpr->iColumn = (i16)iCol; 461 eNewExprOp = TK_TRIGGER; 462 #ifndef SQLITE_OMIT_TRIGGER 463 if( iCol<0 ){ 464 pExpr->affExpr = SQLITE_AFF_INTEGER; 465 }else if( pExpr->iTable==0 ){ 466 testcase( iCol==31 ); 467 testcase( iCol==32 ); 468 pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 469 }else{ 470 testcase( iCol==31 ); 471 testcase( iCol==32 ); 472 pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 473 } 474 #endif /* SQLITE_OMIT_TRIGGER */ 475 } 476 } 477 } 478 } 479 } 480 #endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */ 481 482 /* 483 ** Perhaps the name is a reference to the ROWID 484 */ 485 if( cnt==0 486 && cntTab==1 487 && pMatch 488 && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0 489 && sqlite3IsRowid(zCol) 490 && ALWAYS(VisibleRowid(pMatch->pTab)) 491 ){ 492 cnt = 1; 493 pExpr->iColumn = -1; 494 pExpr->affExpr = SQLITE_AFF_INTEGER; 495 } 496 497 /* 498 ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z 499 ** might refer to an result-set alias. This happens, for example, when 500 ** we are resolving names in the WHERE clause of the following command: 501 ** 502 ** SELECT a+b AS x FROM table WHERE x<10; 503 ** 504 ** In cases like this, replace pExpr with a copy of the expression that 505 ** forms the result set entry ("a+b" in the example) and return immediately. 506 ** Note that the expression in the result set should have already been 507 ** resolved by the time the WHERE clause is resolved. 508 ** 509 ** The ability to use an output result-set column in the WHERE, GROUP BY, 510 ** or HAVING clauses, or as part of a larger expression in the ORDER BY 511 ** clause is not standard SQL. This is a (goofy) SQLite extension, that 512 ** is supported for backwards compatibility only. Hence, we issue a warning 513 ** on sqlite3_log() whenever the capability is used. 514 */ 515 if( cnt==0 516 && (pNC->ncFlags & NC_UEList)!=0 517 && zTab==0 518 ){ 519 pEList = pNC->uNC.pEList; 520 assert( pEList!=0 ); 521 for(j=0; j<pEList->nExpr; j++){ 522 char *zAs = pEList->a[j].zEName; 523 if( pEList->a[j].eEName==ENAME_NAME 524 && sqlite3_stricmp(zAs, zCol)==0 525 ){ 526 Expr *pOrig; 527 assert( pExpr->pLeft==0 && pExpr->pRight==0 ); 528 assert( ExprUseXList(pExpr)==0 || pExpr->x.pList==0 ); 529 assert( ExprUseXSelect(pExpr)==0 || pExpr->x.pSelect==0 ); 530 pOrig = pEList->a[j].pExpr; 531 if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){ 532 sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs); 533 return WRC_Abort; 534 } 535 if( ExprHasProperty(pOrig, EP_Win) 536 && ((pNC->ncFlags&NC_AllowWin)==0 || pNC!=pTopNC ) 537 ){ 538 sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs); 539 return WRC_Abort; 540 } 541 if( sqlite3ExprVectorSize(pOrig)!=1 ){ 542 sqlite3ErrorMsg(pParse, "row value misused"); 543 return WRC_Abort; 544 } 545 resolveAlias(pParse, pEList, j, pExpr, nSubquery); 546 cnt = 1; 547 pMatch = 0; 548 assert( zTab==0 && zDb==0 ); 549 if( IN_RENAME_OBJECT ){ 550 sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr); 551 } 552 goto lookupname_end; 553 } 554 } 555 } 556 557 /* Advance to the next name context. The loop will exit when either 558 ** we have a match (cnt>0) or when we run out of name contexts. 559 */ 560 if( cnt ) break; 561 pNC = pNC->pNext; 562 nSubquery++; 563 }while( pNC ); 564 565 566 /* 567 ** If X and Y are NULL (in other words if only the column name Z is 568 ** supplied) and the value of Z is enclosed in double-quotes, then 569 ** Z is a string literal if it doesn't match any column names. In that 570 ** case, we need to return right away and not make any changes to 571 ** pExpr. 572 ** 573 ** Because no reference was made to outer contexts, the pNC->nRef 574 ** fields are not changed in any context. 575 */ 576 if( cnt==0 && zTab==0 ){ 577 assert( pExpr->op==TK_ID ); 578 if( ExprHasProperty(pExpr,EP_DblQuoted) 579 && areDoubleQuotedStringsEnabled(db, pTopNC) 580 ){ 581 /* If a double-quoted identifier does not match any known column name, 582 ** then treat it as a string. 583 ** 584 ** This hack was added in the early days of SQLite in a misguided attempt 585 ** to be compatible with MySQL 3.x, which used double-quotes for strings. 586 ** I now sorely regret putting in this hack. The effect of this hack is 587 ** that misspelled identifier names are silently converted into strings 588 ** rather than causing an error, to the frustration of countless 589 ** programmers. To all those frustrated programmers, my apologies. 590 ** 591 ** Someday, I hope to get rid of this hack. Unfortunately there is 592 ** a huge amount of legacy SQL that uses it. So for now, we just 593 ** issue a warning. 594 */ 595 sqlite3_log(SQLITE_WARNING, 596 "double-quoted string literal: \"%w\"", zCol); 597 #ifdef SQLITE_ENABLE_NORMALIZE 598 sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol); 599 #endif 600 pExpr->op = TK_STRING; 601 memset(&pExpr->y, 0, sizeof(pExpr->y)); 602 return WRC_Prune; 603 } 604 if( sqlite3ExprIdToTrueFalse(pExpr) ){ 605 return WRC_Prune; 606 } 607 } 608 609 /* 610 ** cnt==0 means there was not match. cnt>1 means there were two or 611 ** more matches. Either way, we have an error. 612 */ 613 if( cnt!=1 ){ 614 const char *zErr; 615 zErr = cnt==0 ? "no such column" : "ambiguous column name"; 616 if( zDb ){ 617 sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol); 618 }else if( zTab ){ 619 sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol); 620 }else{ 621 sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol); 622 } 623 pParse->checkSchema = 1; 624 pTopNC->nNcErr++; 625 } 626 627 /* If a column from a table in pSrcList is referenced, then record 628 ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes 629 ** bit 0 to be set. Column 1 sets bit 1. And so forth. Bit 63 is 630 ** set if the 63rd or any subsequent column is used. 631 ** 632 ** The colUsed mask is an optimization used to help determine if an 633 ** index is a covering index. The correct answer is still obtained 634 ** if the mask contains extra set bits. However, it is important to 635 ** avoid setting bits beyond the maximum column number of the table. 636 ** (See ticket [b92e5e8ec2cdbaa1]). 637 ** 638 ** If a generated column is referenced, set bits for every column 639 ** of the table. 640 */ 641 if( pExpr->iColumn>=0 && pMatch!=0 ){ 642 pMatch->colUsed |= sqlite3ExprColUsed(pExpr); 643 } 644 645 /* Clean up and return 646 */ 647 if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){ 648 sqlite3ExprDelete(db, pExpr->pLeft); 649 pExpr->pLeft = 0; 650 sqlite3ExprDelete(db, pExpr->pRight); 651 pExpr->pRight = 0; 652 } 653 pExpr->op = eNewExprOp; 654 ExprSetProperty(pExpr, EP_Leaf); 655 lookupname_end: 656 if( cnt==1 ){ 657 assert( pNC!=0 ); 658 #ifndef SQLITE_OMIT_AUTHORIZATION 659 if( pParse->db->xAuth 660 && (pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER) 661 ){ 662 sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); 663 } 664 #endif 665 /* Increment the nRef value on all name contexts from TopNC up to 666 ** the point where the name matched. */ 667 for(;;){ 668 assert( pTopNC!=0 ); 669 pTopNC->nRef++; 670 if( pTopNC==pNC ) break; 671 pTopNC = pTopNC->pNext; 672 } 673 return WRC_Prune; 674 } else { 675 return WRC_Abort; 676 } 677 } 678 679 /* 680 ** Allocate and return a pointer to an expression to load the column iCol 681 ** from datasource iSrc in SrcList pSrc. 682 */ 683 Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){ 684 Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0); 685 if( p ){ 686 SrcItem *pItem = &pSrc->a[iSrc]; 687 Table *pTab; 688 assert( ExprUseYTab(p) ); 689 pTab = p->y.pTab = pItem->pTab; 690 p->iTable = pItem->iCursor; 691 if( p->y.pTab->iPKey==iCol ){ 692 p->iColumn = -1; 693 }else{ 694 p->iColumn = (ynVar)iCol; 695 if( (pTab->tabFlags & TF_HasGenerated)!=0 696 && (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0 697 ){ 698 testcase( pTab->nCol==63 ); 699 testcase( pTab->nCol==64 ); 700 pItem->colUsed = pTab->nCol>=64 ? ALLBITS : MASKBIT(pTab->nCol)-1; 701 }else{ 702 testcase( iCol==BMS ); 703 testcase( iCol==BMS-1 ); 704 pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol); 705 } 706 } 707 } 708 return p; 709 } 710 711 /* 712 ** Report an error that an expression is not valid for some set of 713 ** pNC->ncFlags values determined by validMask. 714 ** 715 ** static void notValid( 716 ** Parse *pParse, // Leave error message here 717 ** NameContext *pNC, // The name context 718 ** const char *zMsg, // Type of error 719 ** int validMask, // Set of contexts for which prohibited 720 ** Expr *pExpr // Invalidate this expression on error 721 ** ){...} 722 ** 723 ** As an optimization, since the conditional is almost always false 724 ** (because errors are rare), the conditional is moved outside of the 725 ** function call using a macro. 726 */ 727 static void notValidImpl( 728 Parse *pParse, /* Leave error message here */ 729 NameContext *pNC, /* The name context */ 730 const char *zMsg, /* Type of error */ 731 Expr *pExpr /* Invalidate this expression on error */ 732 ){ 733 const char *zIn = "partial index WHERE clauses"; 734 if( pNC->ncFlags & NC_IdxExpr ) zIn = "index expressions"; 735 #ifndef SQLITE_OMIT_CHECK 736 else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints"; 737 #endif 738 #ifndef SQLITE_OMIT_GENERATED_COLUMNS 739 else if( pNC->ncFlags & NC_GenCol ) zIn = "generated columns"; 740 #endif 741 sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn); 742 if( pExpr ) pExpr->op = TK_NULL; 743 } 744 #define sqlite3ResolveNotValid(P,N,M,X,E) \ 745 assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \ 746 if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E); 747 748 /* 749 ** Expression p should encode a floating point value between 1.0 and 0.0. 750 ** Return 1024 times this value. Or return -1 if p is not a floating point 751 ** value between 1.0 and 0.0. 752 */ 753 static int exprProbability(Expr *p){ 754 double r = -1.0; 755 if( p->op!=TK_FLOAT ) return -1; 756 assert( !ExprHasProperty(p, EP_IntValue) ); 757 sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8); 758 assert( r>=0.0 ); 759 if( r>1.0 ) return -1; 760 return (int)(r*134217728.0); 761 } 762 763 /* 764 ** This routine is callback for sqlite3WalkExpr(). 765 ** 766 ** Resolve symbolic names into TK_COLUMN operators for the current 767 ** node in the expression tree. Return 0 to continue the search down 768 ** the tree or 2 to abort the tree walk. 769 ** 770 ** This routine also does error checking and name resolution for 771 ** function names. The operator for aggregate functions is changed 772 ** to TK_AGG_FUNCTION. 773 */ 774 static int resolveExprStep(Walker *pWalker, Expr *pExpr){ 775 NameContext *pNC; 776 Parse *pParse; 777 778 pNC = pWalker->u.pNC; 779 assert( pNC!=0 ); 780 pParse = pNC->pParse; 781 assert( pParse==pWalker->pParse ); 782 783 #ifndef NDEBUG 784 if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ 785 SrcList *pSrcList = pNC->pSrcList; 786 int i; 787 for(i=0; i<pNC->pSrcList->nSrc; i++){ 788 assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); 789 } 790 } 791 #endif 792 switch( pExpr->op ){ 793 794 /* The special operator TK_ROW means use the rowid for the first 795 ** column in the FROM clause. This is used by the LIMIT and ORDER BY 796 ** clause processing on UPDATE and DELETE statements, and by 797 ** UPDATE ... FROM statement processing. 798 */ 799 case TK_ROW: { 800 SrcList *pSrcList = pNC->pSrcList; 801 SrcItem *pItem; 802 assert( pSrcList && pSrcList->nSrc>=1 ); 803 pItem = pSrcList->a; 804 pExpr->op = TK_COLUMN; 805 assert( ExprUseYTab(pExpr) ); 806 pExpr->y.pTab = pItem->pTab; 807 pExpr->iTable = pItem->iCursor; 808 pExpr->iColumn--; 809 pExpr->affExpr = SQLITE_AFF_INTEGER; 810 break; 811 } 812 813 /* An optimization: Attempt to convert 814 ** 815 ** "expr IS NOT NULL" --> "TRUE" 816 ** "expr IS NULL" --> "FALSE" 817 ** 818 ** if we can prove that "expr" is never NULL. Call this the 819 ** "NOT NULL strength reduction optimization". 820 ** 821 ** If this optimization occurs, also restore the NameContext ref-counts 822 ** to the state they where in before the "column" LHS expression was 823 ** resolved. This prevents "column" from being counted as having been 824 ** referenced, which might prevent a SELECT from being erroneously 825 ** marked as correlated. 826 */ 827 case TK_NOTNULL: 828 case TK_ISNULL: { 829 int anRef[8]; 830 NameContext *p; 831 int i; 832 for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ 833 anRef[i] = p->nRef; 834 } 835 sqlite3WalkExpr(pWalker, pExpr->pLeft); 836 if( 0==sqlite3ExprCanBeNull(pExpr->pLeft) && !IN_RENAME_OBJECT ){ 837 testcase( ExprHasProperty(pExpr, EP_FromJoin) ); 838 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 839 if( pExpr->op==TK_NOTNULL ){ 840 pExpr->u.zToken = "true"; 841 ExprSetProperty(pExpr, EP_IsTrue); 842 }else{ 843 pExpr->u.zToken = "false"; 844 ExprSetProperty(pExpr, EP_IsFalse); 845 } 846 pExpr->op = TK_TRUEFALSE; 847 for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ 848 p->nRef = anRef[i]; 849 } 850 sqlite3ExprDelete(pParse->db, pExpr->pLeft); 851 pExpr->pLeft = 0; 852 } 853 return WRC_Prune; 854 } 855 856 /* A column name: ID 857 ** Or table name and column name: ID.ID 858 ** Or a database, table and column: ID.ID.ID 859 ** 860 ** The TK_ID and TK_OUT cases are combined so that there will only 861 ** be one call to lookupName(). Then the compiler will in-line 862 ** lookupName() for a size reduction and performance increase. 863 */ 864 case TK_ID: 865 case TK_DOT: { 866 const char *zColumn; 867 const char *zTable; 868 const char *zDb; 869 Expr *pRight; 870 871 if( pExpr->op==TK_ID ){ 872 zDb = 0; 873 zTable = 0; 874 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 875 zColumn = pExpr->u.zToken; 876 }else{ 877 Expr *pLeft = pExpr->pLeft; 878 testcase( pNC->ncFlags & NC_IdxExpr ); 879 testcase( pNC->ncFlags & NC_GenCol ); 880 sqlite3ResolveNotValid(pParse, pNC, "the \".\" operator", 881 NC_IdxExpr|NC_GenCol, 0); 882 pRight = pExpr->pRight; 883 if( pRight->op==TK_ID ){ 884 zDb = 0; 885 }else{ 886 assert( pRight->op==TK_DOT ); 887 assert( !ExprHasProperty(pRight, EP_IntValue) ); 888 zDb = pLeft->u.zToken; 889 pLeft = pRight->pLeft; 890 pRight = pRight->pRight; 891 } 892 assert( ExprUseUToken(pLeft) && ExprUseUToken(pRight) ); 893 zTable = pLeft->u.zToken; 894 zColumn = pRight->u.zToken; 895 assert( ExprUseYTab(pExpr) ); 896 if( IN_RENAME_OBJECT ){ 897 sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight); 898 sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft); 899 } 900 } 901 return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr); 902 } 903 904 /* Resolve function names 905 */ 906 case TK_FUNCTION: { 907 ExprList *pList = pExpr->x.pList; /* The argument list */ 908 int n = pList ? pList->nExpr : 0; /* Number of arguments */ 909 int no_such_func = 0; /* True if no such function exists */ 910 int wrong_num_args = 0; /* True if wrong number of arguments */ 911 int is_agg = 0; /* True if is an aggregate function */ 912 int nId; /* Number of characters in function name */ 913 const char *zId; /* The function name. */ 914 FuncDef *pDef; /* Information about the function */ 915 u8 enc = ENC(pParse->db); /* The database encoding */ 916 int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin)); 917 #ifndef SQLITE_OMIT_WINDOWFUNC 918 Window *pWin = (IsWindowFunc(pExpr) ? pExpr->y.pWin : 0); 919 #endif 920 assert( !ExprHasProperty(pExpr, EP_xIsSelect|EP_IntValue) ); 921 zId = pExpr->u.zToken; 922 nId = sqlite3Strlen30(zId); 923 pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0); 924 if( pDef==0 ){ 925 pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0); 926 if( pDef==0 ){ 927 no_such_func = 1; 928 }else{ 929 wrong_num_args = 1; 930 } 931 }else{ 932 is_agg = pDef->xFinalize!=0; 933 if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){ 934 ExprSetProperty(pExpr, EP_Unlikely); 935 if( n==2 ){ 936 pExpr->iTable = exprProbability(pList->a[1].pExpr); 937 if( pExpr->iTable<0 ){ 938 sqlite3ErrorMsg(pParse, 939 "second argument to likelihood() must be a " 940 "constant between 0.0 and 1.0"); 941 pNC->nNcErr++; 942 } 943 }else{ 944 /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is 945 ** equivalent to likelihood(X, 0.0625). 946 ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is 947 ** short-hand for likelihood(X,0.0625). 948 ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand 949 ** for likelihood(X,0.9375). 950 ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent 951 ** to likelihood(X,0.9375). */ 952 /* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */ 953 pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120; 954 } 955 } 956 #ifndef SQLITE_OMIT_AUTHORIZATION 957 { 958 int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0); 959 if( auth!=SQLITE_OK ){ 960 if( auth==SQLITE_DENY ){ 961 sqlite3ErrorMsg(pParse, "not authorized to use function: %s", 962 pDef->zName); 963 pNC->nNcErr++; 964 } 965 pExpr->op = TK_NULL; 966 return WRC_Prune; 967 } 968 } 969 #endif 970 if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){ 971 /* For the purposes of the EP_ConstFunc flag, date and time 972 ** functions and other functions that change slowly are considered 973 ** constant because they are constant for the duration of one query. 974 ** This allows them to be factored out of inner loops. */ 975 ExprSetProperty(pExpr,EP_ConstFunc); 976 } 977 if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){ 978 /* Clearly non-deterministic functions like random(), but also 979 ** date/time functions that use 'now', and other functions like 980 ** sqlite_version() that might change over time cannot be used 981 ** in an index or generated column. Curiously, they can be used 982 ** in a CHECK constraint. SQLServer, MySQL, and PostgreSQL all 983 ** all this. */ 984 sqlite3ResolveNotValid(pParse, pNC, "non-deterministic functions", 985 NC_IdxExpr|NC_PartIdx|NC_GenCol, 0); 986 }else{ 987 assert( (NC_SelfRef & 0xff)==NC_SelfRef ); /* Must fit in 8 bits */ 988 pExpr->op2 = pNC->ncFlags & NC_SelfRef; 989 if( pNC->ncFlags & NC_FromDDL ) ExprSetProperty(pExpr, EP_FromDDL); 990 } 991 if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0 992 && pParse->nested==0 993 && (pParse->db->mDbFlags & DBFLAG_InternalFunc)==0 994 ){ 995 /* Internal-use-only functions are disallowed unless the 996 ** SQL is being compiled using sqlite3NestedParse() or 997 ** the SQLITE_TESTCTRL_INTERNAL_FUNCTIONS test-control has be 998 ** used to activate internal functionsn for testing purposes */ 999 no_such_func = 1; 1000 pDef = 0; 1001 }else 1002 if( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 1003 && !IN_RENAME_OBJECT 1004 ){ 1005 sqlite3ExprFunctionUsable(pParse, pExpr, pDef); 1006 } 1007 } 1008 1009 if( 0==IN_RENAME_OBJECT ){ 1010 #ifndef SQLITE_OMIT_WINDOWFUNC 1011 assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX) 1012 || (pDef->xValue==0 && pDef->xInverse==0) 1013 || (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize) 1014 ); 1015 if( pDef && pDef->xValue==0 && pWin ){ 1016 sqlite3ErrorMsg(pParse, 1017 "%.*s() may not be used as a window function", nId, zId 1018 ); 1019 pNC->nNcErr++; 1020 }else if( 1021 (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) 1022 || (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pWin) 1023 || (is_agg && pWin && (pNC->ncFlags & NC_AllowWin)==0) 1024 ){ 1025 const char *zType; 1026 if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pWin ){ 1027 zType = "window"; 1028 }else{ 1029 zType = "aggregate"; 1030 } 1031 sqlite3ErrorMsg(pParse, "misuse of %s function %.*s()",zType,nId,zId); 1032 pNC->nNcErr++; 1033 is_agg = 0; 1034 } 1035 #else 1036 if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){ 1037 sqlite3ErrorMsg(pParse,"misuse of aggregate function %.*s()",nId,zId); 1038 pNC->nNcErr++; 1039 is_agg = 0; 1040 } 1041 #endif 1042 else if( no_such_func && pParse->db->init.busy==0 1043 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION 1044 && pParse->explain==0 1045 #endif 1046 ){ 1047 sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); 1048 pNC->nNcErr++; 1049 }else if( wrong_num_args ){ 1050 sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", 1051 nId, zId); 1052 pNC->nNcErr++; 1053 } 1054 #ifndef SQLITE_OMIT_WINDOWFUNC 1055 else if( is_agg==0 && ExprHasProperty(pExpr, EP_WinFunc) ){ 1056 sqlite3ErrorMsg(pParse, 1057 "FILTER may not be used with non-aggregate %.*s()", 1058 nId, zId 1059 ); 1060 pNC->nNcErr++; 1061 } 1062 #endif 1063 if( is_agg ){ 1064 /* Window functions may not be arguments of aggregate functions. 1065 ** Or arguments of other window functions. But aggregate functions 1066 ** may be arguments for window functions. */ 1067 #ifndef SQLITE_OMIT_WINDOWFUNC 1068 pNC->ncFlags &= ~(NC_AllowWin | (!pWin ? NC_AllowAgg : 0)); 1069 #else 1070 pNC->ncFlags &= ~NC_AllowAgg; 1071 #endif 1072 } 1073 } 1074 #ifndef SQLITE_OMIT_WINDOWFUNC 1075 else if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1076 is_agg = 1; 1077 } 1078 #endif 1079 sqlite3WalkExprList(pWalker, pList); 1080 if( is_agg ){ 1081 #ifndef SQLITE_OMIT_WINDOWFUNC 1082 if( pWin ){ 1083 Select *pSel = pNC->pWinSelect; 1084 assert( pWin==0 || (ExprUseYWin(pExpr) && pWin==pExpr->y.pWin) ); 1085 if( IN_RENAME_OBJECT==0 ){ 1086 sqlite3WindowUpdate(pParse, pSel ? pSel->pWinDefn : 0, pWin, pDef); 1087 if( pParse->db->mallocFailed ) break; 1088 } 1089 sqlite3WalkExprList(pWalker, pWin->pPartition); 1090 sqlite3WalkExprList(pWalker, pWin->pOrderBy); 1091 sqlite3WalkExpr(pWalker, pWin->pFilter); 1092 sqlite3WindowLink(pSel, pWin); 1093 pNC->ncFlags |= NC_HasWin; 1094 }else 1095 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1096 { 1097 NameContext *pNC2; /* For looping up thru outer contexts */ 1098 pExpr->op = TK_AGG_FUNCTION; 1099 pExpr->op2 = 0; 1100 #ifndef SQLITE_OMIT_WINDOWFUNC 1101 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1102 sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter); 1103 } 1104 #endif 1105 pNC2 = pNC; 1106 while( pNC2 1107 && sqlite3ReferencesSrcList(pParse, pExpr, pNC2->pSrcList)==0 1108 ){ 1109 pExpr->op2++; 1110 pNC2 = pNC2->pNext; 1111 } 1112 assert( pDef!=0 || IN_RENAME_OBJECT ); 1113 if( pNC2 && pDef ){ 1114 assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg ); 1115 assert( SQLITE_FUNC_ANYORDER==NC_OrderAgg ); 1116 testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 ); 1117 testcase( (pDef->funcFlags & SQLITE_FUNC_ANYORDER)!=0 ); 1118 pNC2->ncFlags |= NC_HasAgg 1119 | ((pDef->funcFlags^SQLITE_FUNC_ANYORDER) 1120 & (SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER)); 1121 } 1122 } 1123 pNC->ncFlags |= savedAllowFlags; 1124 } 1125 /* FIX ME: Compute pExpr->affinity based on the expected return 1126 ** type of the function 1127 */ 1128 return WRC_Prune; 1129 } 1130 #ifndef SQLITE_OMIT_SUBQUERY 1131 case TK_SELECT: 1132 case TK_EXISTS: testcase( pExpr->op==TK_EXISTS ); 1133 #endif 1134 case TK_IN: { 1135 testcase( pExpr->op==TK_IN ); 1136 if( ExprUseXSelect(pExpr) ){ 1137 int nRef = pNC->nRef; 1138 testcase( pNC->ncFlags & NC_IsCheck ); 1139 testcase( pNC->ncFlags & NC_PartIdx ); 1140 testcase( pNC->ncFlags & NC_IdxExpr ); 1141 testcase( pNC->ncFlags & NC_GenCol ); 1142 if( pNC->ncFlags & NC_SelfRef ){ 1143 notValidImpl(pParse, pNC, "subqueries", pExpr); 1144 }else{ 1145 sqlite3WalkSelect(pWalker, pExpr->x.pSelect); 1146 } 1147 assert( pNC->nRef>=nRef ); 1148 if( nRef!=pNC->nRef ){ 1149 ExprSetProperty(pExpr, EP_VarSelect); 1150 pNC->ncFlags |= NC_VarSelect; 1151 } 1152 } 1153 break; 1154 } 1155 case TK_VARIABLE: { 1156 testcase( pNC->ncFlags & NC_IsCheck ); 1157 testcase( pNC->ncFlags & NC_PartIdx ); 1158 testcase( pNC->ncFlags & NC_IdxExpr ); 1159 testcase( pNC->ncFlags & NC_GenCol ); 1160 sqlite3ResolveNotValid(pParse, pNC, "parameters", 1161 NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol, pExpr); 1162 break; 1163 } 1164 case TK_IS: 1165 case TK_ISNOT: { 1166 Expr *pRight = sqlite3ExprSkipCollateAndLikely(pExpr->pRight); 1167 assert( !ExprHasProperty(pExpr, EP_Reduced) ); 1168 /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE", 1169 ** and "x IS NOT FALSE". */ 1170 if( ALWAYS(pRight) && (pRight->op==TK_ID || pRight->op==TK_TRUEFALSE) ){ 1171 int rc = resolveExprStep(pWalker, pRight); 1172 if( rc==WRC_Abort ) return WRC_Abort; 1173 if( pRight->op==TK_TRUEFALSE ){ 1174 pExpr->op2 = pExpr->op; 1175 pExpr->op = TK_TRUTH; 1176 return WRC_Continue; 1177 } 1178 } 1179 /* no break */ deliberate_fall_through 1180 } 1181 case TK_BETWEEN: 1182 case TK_EQ: 1183 case TK_NE: 1184 case TK_LT: 1185 case TK_LE: 1186 case TK_GT: 1187 case TK_GE: { 1188 int nLeft, nRight; 1189 if( pParse->db->mallocFailed ) break; 1190 assert( pExpr->pLeft!=0 ); 1191 nLeft = sqlite3ExprVectorSize(pExpr->pLeft); 1192 if( pExpr->op==TK_BETWEEN ){ 1193 assert( ExprUseXList(pExpr) ); 1194 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr); 1195 if( nRight==nLeft ){ 1196 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr); 1197 } 1198 }else{ 1199 assert( pExpr->pRight!=0 ); 1200 nRight = sqlite3ExprVectorSize(pExpr->pRight); 1201 } 1202 if( nLeft!=nRight ){ 1203 testcase( pExpr->op==TK_EQ ); 1204 testcase( pExpr->op==TK_NE ); 1205 testcase( pExpr->op==TK_LT ); 1206 testcase( pExpr->op==TK_LE ); 1207 testcase( pExpr->op==TK_GT ); 1208 testcase( pExpr->op==TK_GE ); 1209 testcase( pExpr->op==TK_IS ); 1210 testcase( pExpr->op==TK_ISNOT ); 1211 testcase( pExpr->op==TK_BETWEEN ); 1212 sqlite3ErrorMsg(pParse, "row value misused"); 1213 } 1214 break; 1215 } 1216 } 1217 return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue; 1218 } 1219 1220 /* 1221 ** pEList is a list of expressions which are really the result set of the 1222 ** a SELECT statement. pE is a term in an ORDER BY or GROUP BY clause. 1223 ** This routine checks to see if pE is a simple identifier which corresponds 1224 ** to the AS-name of one of the terms of the expression list. If it is, 1225 ** this routine return an integer between 1 and N where N is the number of 1226 ** elements in pEList, corresponding to the matching entry. If there is 1227 ** no match, or if pE is not a simple identifier, then this routine 1228 ** return 0. 1229 ** 1230 ** pEList has been resolved. pE has not. 1231 */ 1232 static int resolveAsName( 1233 Parse *pParse, /* Parsing context for error messages */ 1234 ExprList *pEList, /* List of expressions to scan */ 1235 Expr *pE /* Expression we are trying to match */ 1236 ){ 1237 int i; /* Loop counter */ 1238 1239 UNUSED_PARAMETER(pParse); 1240 1241 if( pE->op==TK_ID ){ 1242 const char *zCol; 1243 assert( !ExprHasProperty(pE, EP_IntValue) ); 1244 zCol = pE->u.zToken; 1245 for(i=0; i<pEList->nExpr; i++){ 1246 if( pEList->a[i].eEName==ENAME_NAME 1247 && sqlite3_stricmp(pEList->a[i].zEName, zCol)==0 1248 ){ 1249 return i+1; 1250 } 1251 } 1252 } 1253 return 0; 1254 } 1255 1256 /* 1257 ** pE is a pointer to an expression which is a single term in the 1258 ** ORDER BY of a compound SELECT. The expression has not been 1259 ** name resolved. 1260 ** 1261 ** At the point this routine is called, we already know that the 1262 ** ORDER BY term is not an integer index into the result set. That 1263 ** case is handled by the calling routine. 1264 ** 1265 ** Attempt to match pE against result set columns in the left-most 1266 ** SELECT statement. Return the index i of the matching column, 1267 ** as an indication to the caller that it should sort by the i-th column. 1268 ** The left-most column is 1. In other words, the value returned is the 1269 ** same integer value that would be used in the SQL statement to indicate 1270 ** the column. 1271 ** 1272 ** If there is no match, return 0. Return -1 if an error occurs. 1273 */ 1274 static int resolveOrderByTermToExprList( 1275 Parse *pParse, /* Parsing context for error messages */ 1276 Select *pSelect, /* The SELECT statement with the ORDER BY clause */ 1277 Expr *pE /* The specific ORDER BY term */ 1278 ){ 1279 int i; /* Loop counter */ 1280 ExprList *pEList; /* The columns of the result set */ 1281 NameContext nc; /* Name context for resolving pE */ 1282 sqlite3 *db; /* Database connection */ 1283 int rc; /* Return code from subprocedures */ 1284 u8 savedSuppErr; /* Saved value of db->suppressErr */ 1285 1286 assert( sqlite3ExprIsInteger(pE, &i)==0 ); 1287 pEList = pSelect->pEList; 1288 1289 /* Resolve all names in the ORDER BY term expression 1290 */ 1291 memset(&nc, 0, sizeof(nc)); 1292 nc.pParse = pParse; 1293 nc.pSrcList = pSelect->pSrc; 1294 nc.uNC.pEList = pEList; 1295 nc.ncFlags = NC_AllowAgg|NC_UEList|NC_NoSelect; 1296 nc.nNcErr = 0; 1297 db = pParse->db; 1298 savedSuppErr = db->suppressErr; 1299 db->suppressErr = 1; 1300 rc = sqlite3ResolveExprNames(&nc, pE); 1301 db->suppressErr = savedSuppErr; 1302 if( rc ) return 0; 1303 1304 /* Try to match the ORDER BY expression against an expression 1305 ** in the result set. Return an 1-based index of the matching 1306 ** result-set entry. 1307 */ 1308 for(i=0; i<pEList->nExpr; i++){ 1309 if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){ 1310 return i+1; 1311 } 1312 } 1313 1314 /* If no match, return 0. */ 1315 return 0; 1316 } 1317 1318 /* 1319 ** Generate an ORDER BY or GROUP BY term out-of-range error. 1320 */ 1321 static void resolveOutOfRangeError( 1322 Parse *pParse, /* The error context into which to write the error */ 1323 const char *zType, /* "ORDER" or "GROUP" */ 1324 int i, /* The index (1-based) of the term out of range */ 1325 int mx /* Largest permissible value of i */ 1326 ){ 1327 sqlite3ErrorMsg(pParse, 1328 "%r %s BY term out of range - should be " 1329 "between 1 and %d", i, zType, mx); 1330 } 1331 1332 /* 1333 ** Analyze the ORDER BY clause in a compound SELECT statement. Modify 1334 ** each term of the ORDER BY clause is a constant integer between 1 1335 ** and N where N is the number of columns in the compound SELECT. 1336 ** 1337 ** ORDER BY terms that are already an integer between 1 and N are 1338 ** unmodified. ORDER BY terms that are integers outside the range of 1339 ** 1 through N generate an error. ORDER BY terms that are expressions 1340 ** are matched against result set expressions of compound SELECT 1341 ** beginning with the left-most SELECT and working toward the right. 1342 ** At the first match, the ORDER BY expression is transformed into 1343 ** the integer column number. 1344 ** 1345 ** Return the number of errors seen. 1346 */ 1347 static int resolveCompoundOrderBy( 1348 Parse *pParse, /* Parsing context. Leave error messages here */ 1349 Select *pSelect /* The SELECT statement containing the ORDER BY */ 1350 ){ 1351 int i; 1352 ExprList *pOrderBy; 1353 ExprList *pEList; 1354 sqlite3 *db; 1355 int moreToDo = 1; 1356 1357 pOrderBy = pSelect->pOrderBy; 1358 if( pOrderBy==0 ) return 0; 1359 db = pParse->db; 1360 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1361 sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause"); 1362 return 1; 1363 } 1364 for(i=0; i<pOrderBy->nExpr; i++){ 1365 pOrderBy->a[i].done = 0; 1366 } 1367 pSelect->pNext = 0; 1368 while( pSelect->pPrior ){ 1369 pSelect->pPrior->pNext = pSelect; 1370 pSelect = pSelect->pPrior; 1371 } 1372 while( pSelect && moreToDo ){ 1373 struct ExprList_item *pItem; 1374 moreToDo = 0; 1375 pEList = pSelect->pEList; 1376 assert( pEList!=0 ); 1377 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1378 int iCol = -1; 1379 Expr *pE, *pDup; 1380 if( pItem->done ) continue; 1381 pE = sqlite3ExprSkipCollateAndLikely(pItem->pExpr); 1382 if( NEVER(pE==0) ) continue; 1383 if( sqlite3ExprIsInteger(pE, &iCol) ){ 1384 if( iCol<=0 || iCol>pEList->nExpr ){ 1385 resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr); 1386 return 1; 1387 } 1388 }else{ 1389 iCol = resolveAsName(pParse, pEList, pE); 1390 if( iCol==0 ){ 1391 /* Now test if expression pE matches one of the values returned 1392 ** by pSelect. In the usual case this is done by duplicating the 1393 ** expression, resolving any symbols in it, and then comparing 1394 ** it against each expression returned by the SELECT statement. 1395 ** Once the comparisons are finished, the duplicate expression 1396 ** is deleted. 1397 ** 1398 ** If this is running as part of an ALTER TABLE operation and 1399 ** the symbols resolve successfully, also resolve the symbols in the 1400 ** actual expression. This allows the code in alter.c to modify 1401 ** column references within the ORDER BY expression as required. */ 1402 pDup = sqlite3ExprDup(db, pE, 0); 1403 if( !db->mallocFailed ){ 1404 assert(pDup); 1405 iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup); 1406 if( IN_RENAME_OBJECT && iCol>0 ){ 1407 resolveOrderByTermToExprList(pParse, pSelect, pE); 1408 } 1409 } 1410 sqlite3ExprDelete(db, pDup); 1411 } 1412 } 1413 if( iCol>0 ){ 1414 /* Convert the ORDER BY term into an integer column number iCol, 1415 ** taking care to preserve the COLLATE clause if it exists. */ 1416 if( !IN_RENAME_OBJECT ){ 1417 Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); 1418 if( pNew==0 ) return 1; 1419 pNew->flags |= EP_IntValue; 1420 pNew->u.iValue = iCol; 1421 if( pItem->pExpr==pE ){ 1422 pItem->pExpr = pNew; 1423 }else{ 1424 Expr *pParent = pItem->pExpr; 1425 assert( pParent->op==TK_COLLATE ); 1426 while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft; 1427 assert( pParent->pLeft==pE ); 1428 pParent->pLeft = pNew; 1429 } 1430 sqlite3ExprDelete(db, pE); 1431 pItem->u.x.iOrderByCol = (u16)iCol; 1432 } 1433 pItem->done = 1; 1434 }else{ 1435 moreToDo = 1; 1436 } 1437 } 1438 pSelect = pSelect->pNext; 1439 } 1440 for(i=0; i<pOrderBy->nExpr; i++){ 1441 if( pOrderBy->a[i].done==0 ){ 1442 sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any " 1443 "column in the result set", i+1); 1444 return 1; 1445 } 1446 } 1447 return 0; 1448 } 1449 1450 /* 1451 ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of 1452 ** the SELECT statement pSelect. If any term is reference to a 1453 ** result set expression (as determined by the ExprList.a.u.x.iOrderByCol 1454 ** field) then convert that term into a copy of the corresponding result set 1455 ** column. 1456 ** 1457 ** If any errors are detected, add an error message to pParse and 1458 ** return non-zero. Return zero if no errors are seen. 1459 */ 1460 int sqlite3ResolveOrderGroupBy( 1461 Parse *pParse, /* Parsing context. Leave error messages here */ 1462 Select *pSelect, /* The SELECT statement containing the clause */ 1463 ExprList *pOrderBy, /* The ORDER BY or GROUP BY clause to be processed */ 1464 const char *zType /* "ORDER" or "GROUP" */ 1465 ){ 1466 int i; 1467 sqlite3 *db = pParse->db; 1468 ExprList *pEList; 1469 struct ExprList_item *pItem; 1470 1471 if( pOrderBy==0 || pParse->db->mallocFailed || IN_RENAME_OBJECT ) return 0; 1472 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1473 sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType); 1474 return 1; 1475 } 1476 pEList = pSelect->pEList; 1477 assert( pEList!=0 ); /* sqlite3SelectNew() guarantees this */ 1478 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1479 if( pItem->u.x.iOrderByCol ){ 1480 if( pItem->u.x.iOrderByCol>pEList->nExpr ){ 1481 resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr); 1482 return 1; 1483 } 1484 resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,0); 1485 } 1486 } 1487 return 0; 1488 } 1489 1490 #ifndef SQLITE_OMIT_WINDOWFUNC 1491 /* 1492 ** Walker callback for windowRemoveExprFromSelect(). 1493 */ 1494 static int resolveRemoveWindowsCb(Walker *pWalker, Expr *pExpr){ 1495 UNUSED_PARAMETER(pWalker); 1496 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1497 Window *pWin = pExpr->y.pWin; 1498 sqlite3WindowUnlinkFromSelect(pWin); 1499 } 1500 return WRC_Continue; 1501 } 1502 1503 /* 1504 ** Remove any Window objects owned by the expression pExpr from the 1505 ** Select.pWin list of Select object pSelect. 1506 */ 1507 static void windowRemoveExprFromSelect(Select *pSelect, Expr *pExpr){ 1508 if( pSelect->pWin ){ 1509 Walker sWalker; 1510 memset(&sWalker, 0, sizeof(Walker)); 1511 sWalker.xExprCallback = resolveRemoveWindowsCb; 1512 sWalker.u.pSelect = pSelect; 1513 sqlite3WalkExpr(&sWalker, pExpr); 1514 } 1515 } 1516 #else 1517 # define windowRemoveExprFromSelect(a, b) 1518 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1519 1520 /* 1521 ** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect. 1522 ** The Name context of the SELECT statement is pNC. zType is either 1523 ** "ORDER" or "GROUP" depending on which type of clause pOrderBy is. 1524 ** 1525 ** This routine resolves each term of the clause into an expression. 1526 ** If the order-by term is an integer I between 1 and N (where N is the 1527 ** number of columns in the result set of the SELECT) then the expression 1528 ** in the resolution is a copy of the I-th result-set expression. If 1529 ** the order-by term is an identifier that corresponds to the AS-name of 1530 ** a result-set expression, then the term resolves to a copy of the 1531 ** result-set expression. Otherwise, the expression is resolved in 1532 ** the usual way - using sqlite3ResolveExprNames(). 1533 ** 1534 ** This routine returns the number of errors. If errors occur, then 1535 ** an appropriate error message might be left in pParse. (OOM errors 1536 ** excepted.) 1537 */ 1538 static int resolveOrderGroupBy( 1539 NameContext *pNC, /* The name context of the SELECT statement */ 1540 Select *pSelect, /* The SELECT statement holding pOrderBy */ 1541 ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */ 1542 const char *zType /* Either "ORDER" or "GROUP", as appropriate */ 1543 ){ 1544 int i, j; /* Loop counters */ 1545 int iCol; /* Column number */ 1546 struct ExprList_item *pItem; /* A term of the ORDER BY clause */ 1547 Parse *pParse; /* Parsing context */ 1548 int nResult; /* Number of terms in the result set */ 1549 1550 assert( pOrderBy!=0 ); 1551 nResult = pSelect->pEList->nExpr; 1552 pParse = pNC->pParse; 1553 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1554 Expr *pE = pItem->pExpr; 1555 Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pE); 1556 if( NEVER(pE2==0) ) continue; 1557 if( zType[0]!='G' ){ 1558 iCol = resolveAsName(pParse, pSelect->pEList, pE2); 1559 if( iCol>0 ){ 1560 /* If an AS-name match is found, mark this ORDER BY column as being 1561 ** a copy of the iCol-th result-set column. The subsequent call to 1562 ** sqlite3ResolveOrderGroupBy() will convert the expression to a 1563 ** copy of the iCol-th result-set expression. */ 1564 pItem->u.x.iOrderByCol = (u16)iCol; 1565 continue; 1566 } 1567 } 1568 if( sqlite3ExprIsInteger(pE2, &iCol) ){ 1569 /* The ORDER BY term is an integer constant. Again, set the column 1570 ** number so that sqlite3ResolveOrderGroupBy() will convert the 1571 ** order-by term to a copy of the result-set expression */ 1572 if( iCol<1 || iCol>0xffff ){ 1573 resolveOutOfRangeError(pParse, zType, i+1, nResult); 1574 return 1; 1575 } 1576 pItem->u.x.iOrderByCol = (u16)iCol; 1577 continue; 1578 } 1579 1580 /* Otherwise, treat the ORDER BY term as an ordinary expression */ 1581 pItem->u.x.iOrderByCol = 0; 1582 if( sqlite3ResolveExprNames(pNC, pE) ){ 1583 return 1; 1584 } 1585 for(j=0; j<pSelect->pEList->nExpr; j++){ 1586 if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){ 1587 /* Since this expresion is being changed into a reference 1588 ** to an identical expression in the result set, remove all Window 1589 ** objects belonging to the expression from the Select.pWin list. */ 1590 windowRemoveExprFromSelect(pSelect, pE); 1591 pItem->u.x.iOrderByCol = j+1; 1592 } 1593 } 1594 } 1595 return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType); 1596 } 1597 1598 /* 1599 ** Resolve names in the SELECT statement p and all of its descendants. 1600 */ 1601 static int resolveSelectStep(Walker *pWalker, Select *p){ 1602 NameContext *pOuterNC; /* Context that contains this SELECT */ 1603 NameContext sNC; /* Name context of this SELECT */ 1604 int isCompound; /* True if p is a compound select */ 1605 int nCompound; /* Number of compound terms processed so far */ 1606 Parse *pParse; /* Parsing context */ 1607 int i; /* Loop counter */ 1608 ExprList *pGroupBy; /* The GROUP BY clause */ 1609 Select *pLeftmost; /* Left-most of SELECT of a compound */ 1610 sqlite3 *db; /* Database connection */ 1611 1612 1613 assert( p!=0 ); 1614 if( p->selFlags & SF_Resolved ){ 1615 return WRC_Prune; 1616 } 1617 pOuterNC = pWalker->u.pNC; 1618 pParse = pWalker->pParse; 1619 db = pParse->db; 1620 1621 /* Normally sqlite3SelectExpand() will be called first and will have 1622 ** already expanded this SELECT. However, if this is a subquery within 1623 ** an expression, sqlite3ResolveExprNames() will be called without a 1624 ** prior call to sqlite3SelectExpand(). When that happens, let 1625 ** sqlite3SelectPrep() do all of the processing for this SELECT. 1626 ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and 1627 ** this routine in the correct order. 1628 */ 1629 if( (p->selFlags & SF_Expanded)==0 ){ 1630 sqlite3SelectPrep(pParse, p, pOuterNC); 1631 return (pParse->nErr || db->mallocFailed) ? WRC_Abort : WRC_Prune; 1632 } 1633 1634 isCompound = p->pPrior!=0; 1635 nCompound = 0; 1636 pLeftmost = p; 1637 while( p ){ 1638 assert( (p->selFlags & SF_Expanded)!=0 ); 1639 assert( (p->selFlags & SF_Resolved)==0 ); 1640 assert( db->suppressErr==0 ); /* SF_Resolved not set if errors suppressed */ 1641 p->selFlags |= SF_Resolved; 1642 1643 1644 /* Resolve the expressions in the LIMIT and OFFSET clauses. These 1645 ** are not allowed to refer to any names, so pass an empty NameContext. 1646 */ 1647 memset(&sNC, 0, sizeof(sNC)); 1648 sNC.pParse = pParse; 1649 sNC.pWinSelect = p; 1650 if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){ 1651 return WRC_Abort; 1652 } 1653 1654 /* If the SF_Converted flags is set, then this Select object was 1655 ** was created by the convertCompoundSelectToSubquery() function. 1656 ** In this case the ORDER BY clause (p->pOrderBy) should be resolved 1657 ** as if it were part of the sub-query, not the parent. This block 1658 ** moves the pOrderBy down to the sub-query. It will be moved back 1659 ** after the names have been resolved. */ 1660 if( p->selFlags & SF_Converted ){ 1661 Select *pSub = p->pSrc->a[0].pSelect; 1662 assert( p->pSrc->nSrc==1 && p->pOrderBy ); 1663 assert( pSub->pPrior && pSub->pOrderBy==0 ); 1664 pSub->pOrderBy = p->pOrderBy; 1665 p->pOrderBy = 0; 1666 } 1667 1668 /* Recursively resolve names in all subqueries in the FROM clause 1669 */ 1670 for(i=0; i<p->pSrc->nSrc; i++){ 1671 SrcItem *pItem = &p->pSrc->a[i]; 1672 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){ 1673 int nRef = pOuterNC ? pOuterNC->nRef : 0; 1674 const char *zSavedContext = pParse->zAuthContext; 1675 1676 if( pItem->zName ) pParse->zAuthContext = pItem->zName; 1677 sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC); 1678 pParse->zAuthContext = zSavedContext; 1679 if( pParse->nErr || db->mallocFailed ) return WRC_Abort; 1680 1681 /* If the number of references to the outer context changed when 1682 ** expressions in the sub-select were resolved, the sub-select 1683 ** is correlated. It is not required to check the refcount on any 1684 ** but the innermost outer context object, as lookupName() increments 1685 ** the refcount on all contexts between the current one and the 1686 ** context containing the column when it resolves a name. */ 1687 if( pOuterNC ){ 1688 assert( pItem->fg.isCorrelated==0 && pOuterNC->nRef>=nRef ); 1689 pItem->fg.isCorrelated = (pOuterNC->nRef>nRef); 1690 } 1691 } 1692 } 1693 1694 /* Set up the local name-context to pass to sqlite3ResolveExprNames() to 1695 ** resolve the result-set expression list. 1696 */ 1697 sNC.ncFlags = NC_AllowAgg|NC_AllowWin; 1698 sNC.pSrcList = p->pSrc; 1699 sNC.pNext = pOuterNC; 1700 1701 /* Resolve names in the result set. */ 1702 if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort; 1703 sNC.ncFlags &= ~NC_AllowWin; 1704 1705 /* If there are no aggregate functions in the result-set, and no GROUP BY 1706 ** expression, do not allow aggregates in any of the other expressions. 1707 */ 1708 assert( (p->selFlags & SF_Aggregate)==0 ); 1709 pGroupBy = p->pGroupBy; 1710 if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){ 1711 assert( NC_MinMaxAgg==SF_MinMaxAgg ); 1712 assert( NC_OrderAgg==SF_OrderByReqd ); 1713 p->selFlags |= SF_Aggregate | (sNC.ncFlags&(NC_MinMaxAgg|NC_OrderAgg)); 1714 }else{ 1715 sNC.ncFlags &= ~NC_AllowAgg; 1716 } 1717 1718 /* Add the output column list to the name-context before parsing the 1719 ** other expressions in the SELECT statement. This is so that 1720 ** expressions in the WHERE clause (etc.) can refer to expressions by 1721 ** aliases in the result set. 1722 ** 1723 ** Minor point: If this is the case, then the expression will be 1724 ** re-evaluated for each reference to it. 1725 */ 1726 assert( (sNC.ncFlags & (NC_UAggInfo|NC_UUpsert|NC_UBaseReg))==0 ); 1727 sNC.uNC.pEList = p->pEList; 1728 sNC.ncFlags |= NC_UEList; 1729 if( p->pHaving ){ 1730 if( !pGroupBy ){ 1731 sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING"); 1732 return WRC_Abort; 1733 } 1734 if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort; 1735 } 1736 if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort; 1737 1738 /* Resolve names in table-valued-function arguments */ 1739 for(i=0; i<p->pSrc->nSrc; i++){ 1740 SrcItem *pItem = &p->pSrc->a[i]; 1741 if( pItem->fg.isTabFunc 1742 && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 1743 ){ 1744 return WRC_Abort; 1745 } 1746 } 1747 1748 #ifndef SQLITE_OMIT_WINDOWFUNC 1749 if( IN_RENAME_OBJECT ){ 1750 Window *pWin; 1751 for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){ 1752 if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy) 1753 || sqlite3ResolveExprListNames(&sNC, pWin->pPartition) 1754 ){ 1755 return WRC_Abort; 1756 } 1757 } 1758 } 1759 #endif 1760 1761 /* The ORDER BY and GROUP BY clauses may not refer to terms in 1762 ** outer queries 1763 */ 1764 sNC.pNext = 0; 1765 sNC.ncFlags |= NC_AllowAgg|NC_AllowWin; 1766 1767 /* If this is a converted compound query, move the ORDER BY clause from 1768 ** the sub-query back to the parent query. At this point each term 1769 ** within the ORDER BY clause has been transformed to an integer value. 1770 ** These integers will be replaced by copies of the corresponding result 1771 ** set expressions by the call to resolveOrderGroupBy() below. */ 1772 if( p->selFlags & SF_Converted ){ 1773 Select *pSub = p->pSrc->a[0].pSelect; 1774 p->pOrderBy = pSub->pOrderBy; 1775 pSub->pOrderBy = 0; 1776 } 1777 1778 /* Process the ORDER BY clause for singleton SELECT statements. 1779 ** The ORDER BY clause for compounds SELECT statements is handled 1780 ** below, after all of the result-sets for all of the elements of 1781 ** the compound have been resolved. 1782 ** 1783 ** If there is an ORDER BY clause on a term of a compound-select other 1784 ** than the right-most term, then that is a syntax error. But the error 1785 ** is not detected until much later, and so we need to go ahead and 1786 ** resolve those symbols on the incorrect ORDER BY for consistency. 1787 */ 1788 if( p->pOrderBy!=0 1789 && isCompound<=nCompound /* Defer right-most ORDER BY of a compound */ 1790 && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") 1791 ){ 1792 return WRC_Abort; 1793 } 1794 if( db->mallocFailed ){ 1795 return WRC_Abort; 1796 } 1797 sNC.ncFlags &= ~NC_AllowWin; 1798 1799 /* Resolve the GROUP BY clause. At the same time, make sure 1800 ** the GROUP BY clause does not contain aggregate functions. 1801 */ 1802 if( pGroupBy ){ 1803 struct ExprList_item *pItem; 1804 1805 if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){ 1806 return WRC_Abort; 1807 } 1808 for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){ 1809 if( ExprHasProperty(pItem->pExpr, EP_Agg) ){ 1810 sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in " 1811 "the GROUP BY clause"); 1812 return WRC_Abort; 1813 } 1814 } 1815 } 1816 1817 /* If this is part of a compound SELECT, check that it has the right 1818 ** number of expressions in the select list. */ 1819 if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){ 1820 sqlite3SelectWrongNumTermsError(pParse, p->pNext); 1821 return WRC_Abort; 1822 } 1823 1824 /* Advance to the next term of the compound 1825 */ 1826 p = p->pPrior; 1827 nCompound++; 1828 } 1829 1830 /* Resolve the ORDER BY on a compound SELECT after all terms of 1831 ** the compound have been resolved. 1832 */ 1833 if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){ 1834 return WRC_Abort; 1835 } 1836 1837 return WRC_Prune; 1838 } 1839 1840 /* 1841 ** This routine walks an expression tree and resolves references to 1842 ** table columns and result-set columns. At the same time, do error 1843 ** checking on function usage and set a flag if any aggregate functions 1844 ** are seen. 1845 ** 1846 ** To resolve table columns references we look for nodes (or subtrees) of the 1847 ** form X.Y.Z or Y.Z or just Z where 1848 ** 1849 ** X: The name of a database. Ex: "main" or "temp" or 1850 ** the symbolic name assigned to an ATTACH-ed database. 1851 ** 1852 ** Y: The name of a table in a FROM clause. Or in a trigger 1853 ** one of the special names "old" or "new". 1854 ** 1855 ** Z: The name of a column in table Y. 1856 ** 1857 ** The node at the root of the subtree is modified as follows: 1858 ** 1859 ** Expr.op Changed to TK_COLUMN 1860 ** Expr.pTab Points to the Table object for X.Y 1861 ** Expr.iColumn The column index in X.Y. -1 for the rowid. 1862 ** Expr.iTable The VDBE cursor number for X.Y 1863 ** 1864 ** 1865 ** To resolve result-set references, look for expression nodes of the 1866 ** form Z (with no X and Y prefix) where the Z matches the right-hand 1867 ** size of an AS clause in the result-set of a SELECT. The Z expression 1868 ** is replaced by a copy of the left-hand side of the result-set expression. 1869 ** Table-name and function resolution occurs on the substituted expression 1870 ** tree. For example, in: 1871 ** 1872 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x; 1873 ** 1874 ** The "x" term of the order by is replaced by "a+b" to render: 1875 ** 1876 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b; 1877 ** 1878 ** Function calls are checked to make sure that the function is 1879 ** defined and that the correct number of arguments are specified. 1880 ** If the function is an aggregate function, then the NC_HasAgg flag is 1881 ** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION. 1882 ** If an expression contains aggregate functions then the EP_Agg 1883 ** property on the expression is set. 1884 ** 1885 ** An error message is left in pParse if anything is amiss. The number 1886 ** if errors is returned. 1887 */ 1888 int sqlite3ResolveExprNames( 1889 NameContext *pNC, /* Namespace to resolve expressions in. */ 1890 Expr *pExpr /* The expression to be analyzed. */ 1891 ){ 1892 int savedHasAgg; 1893 Walker w; 1894 1895 if( pExpr==0 ) return SQLITE_OK; 1896 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1897 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1898 w.pParse = pNC->pParse; 1899 w.xExprCallback = resolveExprStep; 1900 w.xSelectCallback = (pNC->ncFlags & NC_NoSelect) ? 0 : resolveSelectStep; 1901 w.xSelectCallback2 = 0; 1902 w.u.pNC = pNC; 1903 #if SQLITE_MAX_EXPR_DEPTH>0 1904 w.pParse->nHeight += pExpr->nHeight; 1905 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1906 return SQLITE_ERROR; 1907 } 1908 #endif 1909 sqlite3WalkExpr(&w, pExpr); 1910 #if SQLITE_MAX_EXPR_DEPTH>0 1911 w.pParse->nHeight -= pExpr->nHeight; 1912 #endif 1913 assert( EP_Agg==NC_HasAgg ); 1914 assert( EP_Win==NC_HasWin ); 1915 testcase( pNC->ncFlags & NC_HasAgg ); 1916 testcase( pNC->ncFlags & NC_HasWin ); 1917 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1918 pNC->ncFlags |= savedHasAgg; 1919 return pNC->nNcErr>0 || w.pParse->nErr>0; 1920 } 1921 1922 /* 1923 ** Resolve all names for all expression in an expression list. This is 1924 ** just like sqlite3ResolveExprNames() except that it works for an expression 1925 ** list rather than a single expression. 1926 */ 1927 int sqlite3ResolveExprListNames( 1928 NameContext *pNC, /* Namespace to resolve expressions in. */ 1929 ExprList *pList /* The expression list to be analyzed. */ 1930 ){ 1931 int i; 1932 int savedHasAgg = 0; 1933 Walker w; 1934 if( pList==0 ) return WRC_Continue; 1935 w.pParse = pNC->pParse; 1936 w.xExprCallback = resolveExprStep; 1937 w.xSelectCallback = resolveSelectStep; 1938 w.xSelectCallback2 = 0; 1939 w.u.pNC = pNC; 1940 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1941 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1942 for(i=0; i<pList->nExpr; i++){ 1943 Expr *pExpr = pList->a[i].pExpr; 1944 if( pExpr==0 ) continue; 1945 #if SQLITE_MAX_EXPR_DEPTH>0 1946 w.pParse->nHeight += pExpr->nHeight; 1947 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1948 return WRC_Abort; 1949 } 1950 #endif 1951 sqlite3WalkExpr(&w, pExpr); 1952 #if SQLITE_MAX_EXPR_DEPTH>0 1953 w.pParse->nHeight -= pExpr->nHeight; 1954 #endif 1955 assert( EP_Agg==NC_HasAgg ); 1956 assert( EP_Win==NC_HasWin ); 1957 testcase( pNC->ncFlags & NC_HasAgg ); 1958 testcase( pNC->ncFlags & NC_HasWin ); 1959 if( pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg) ){ 1960 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1961 savedHasAgg |= pNC->ncFlags & 1962 (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1963 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1964 } 1965 if( w.pParse->nErr>0 ) return WRC_Abort; 1966 } 1967 pNC->ncFlags |= savedHasAgg; 1968 return WRC_Continue; 1969 } 1970 1971 /* 1972 ** Resolve all names in all expressions of a SELECT and in all 1973 ** decendents of the SELECT, including compounds off of p->pPrior, 1974 ** subqueries in expressions, and subqueries used as FROM clause 1975 ** terms. 1976 ** 1977 ** See sqlite3ResolveExprNames() for a description of the kinds of 1978 ** transformations that occur. 1979 ** 1980 ** All SELECT statements should have been expanded using 1981 ** sqlite3SelectExpand() prior to invoking this routine. 1982 */ 1983 void sqlite3ResolveSelectNames( 1984 Parse *pParse, /* The parser context */ 1985 Select *p, /* The SELECT statement being coded. */ 1986 NameContext *pOuterNC /* Name context for parent SELECT statement */ 1987 ){ 1988 Walker w; 1989 1990 assert( p!=0 ); 1991 w.xExprCallback = resolveExprStep; 1992 w.xSelectCallback = resolveSelectStep; 1993 w.xSelectCallback2 = 0; 1994 w.pParse = pParse; 1995 w.u.pNC = pOuterNC; 1996 sqlite3WalkSelect(&w, p); 1997 } 1998 1999 /* 2000 ** Resolve names in expressions that can only reference a single table 2001 ** or which cannot reference any tables at all. Examples: 2002 ** 2003 ** "type" flag 2004 ** ------------ 2005 ** (1) CHECK constraints NC_IsCheck 2006 ** (2) WHERE clauses on partial indices NC_PartIdx 2007 ** (3) Expressions in indexes on expressions NC_IdxExpr 2008 ** (4) Expression arguments to VACUUM INTO. 0 2009 ** (5) GENERATED ALWAYS as expressions NC_GenCol 2010 ** 2011 ** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN 2012 ** nodes of the expression is set to -1 and the Expr.iColumn value is 2013 ** set to the column number. In case (4), TK_COLUMN nodes cause an error. 2014 ** 2015 ** Any errors cause an error message to be set in pParse. 2016 */ 2017 int sqlite3ResolveSelfReference( 2018 Parse *pParse, /* Parsing context */ 2019 Table *pTab, /* The table being referenced, or NULL */ 2020 int type, /* NC_IsCheck, NC_PartIdx, NC_IdxExpr, NC_GenCol, or 0 */ 2021 Expr *pExpr, /* Expression to resolve. May be NULL. */ 2022 ExprList *pList /* Expression list to resolve. May be NULL. */ 2023 ){ 2024 SrcList sSrc; /* Fake SrcList for pParse->pNewTable */ 2025 NameContext sNC; /* Name context for pParse->pNewTable */ 2026 int rc; 2027 2028 assert( type==0 || pTab!=0 ); 2029 assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr 2030 || type==NC_GenCol || pTab==0 ); 2031 memset(&sNC, 0, sizeof(sNC)); 2032 memset(&sSrc, 0, sizeof(sSrc)); 2033 if( pTab ){ 2034 sSrc.nSrc = 1; 2035 sSrc.a[0].zName = pTab->zName; 2036 sSrc.a[0].pTab = pTab; 2037 sSrc.a[0].iCursor = -1; 2038 if( pTab->pSchema!=pParse->db->aDb[1].pSchema ){ 2039 /* Cause EP_FromDDL to be set on TK_FUNCTION nodes of non-TEMP 2040 ** schema elements */ 2041 type |= NC_FromDDL; 2042 } 2043 } 2044 sNC.pParse = pParse; 2045 sNC.pSrcList = &sSrc; 2046 sNC.ncFlags = type | NC_IsDDL; 2047 if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc; 2048 if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList); 2049 return rc; 2050 } 2051