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 int k; 127 assert( pUsing!=0 ); 128 for(k=0; k<pUsing->nId; k++){ 129 if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ) return 1; 130 } 131 return 0; 132 } 133 134 /* 135 ** Subqueries stores the original database, table and column names for their 136 ** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN". 137 ** Check to see if the zSpan given to this routine matches the zDb, zTab, 138 ** and zCol. If any of zDb, zTab, and zCol are NULL then those fields will 139 ** match anything. 140 */ 141 int sqlite3MatchEName( 142 const struct ExprList_item *pItem, 143 const char *zCol, 144 const char *zTab, 145 const char *zDb 146 ){ 147 int n; 148 const char *zSpan; 149 if( pItem->eEName!=ENAME_TAB ) return 0; 150 zSpan = pItem->zEName; 151 for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} 152 if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){ 153 return 0; 154 } 155 zSpan += n+1; 156 for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} 157 if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){ 158 return 0; 159 } 160 zSpan += n+1; 161 if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){ 162 return 0; 163 } 164 return 1; 165 } 166 167 /* 168 ** Return TRUE if the double-quoted string mis-feature should be supported. 169 */ 170 static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){ 171 if( db->init.busy ) return 1; /* Always support for legacy schemas */ 172 if( pTopNC->ncFlags & NC_IsDDL ){ 173 /* Currently parsing a DDL statement */ 174 if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){ 175 return 1; 176 } 177 return (db->flags & SQLITE_DqsDDL)!=0; 178 }else{ 179 /* Currently parsing a DML statement */ 180 return (db->flags & SQLITE_DqsDML)!=0; 181 } 182 } 183 184 /* 185 ** The argument is guaranteed to be a non-NULL Expr node of type TK_COLUMN. 186 ** return the appropriate colUsed mask. 187 */ 188 Bitmask sqlite3ExprColUsed(Expr *pExpr){ 189 int n; 190 Table *pExTab; 191 192 n = pExpr->iColumn; 193 assert( ExprUseYTab(pExpr) ); 194 pExTab = pExpr->y.pTab; 195 assert( pExTab!=0 ); 196 if( (pExTab->tabFlags & TF_HasGenerated)!=0 197 && (pExTab->aCol[n].colFlags & COLFLAG_GENERATED)!=0 198 ){ 199 testcase( pExTab->nCol==BMS-1 ); 200 testcase( pExTab->nCol==BMS ); 201 return pExTab->nCol>=BMS ? ALLBITS : MASKBIT(pExTab->nCol)-1; 202 }else{ 203 testcase( n==BMS-1 ); 204 testcase( n==BMS ); 205 if( n>=BMS ) n = BMS-1; 206 return ((Bitmask)1)<<n; 207 } 208 } 209 210 /* 211 ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up 212 ** that name in the set of source tables in pSrcList and make the pExpr 213 ** expression node refer back to that source column. The following changes 214 ** are made to pExpr: 215 ** 216 ** pExpr->iDb Set the index in db->aDb[] of the database X 217 ** (even if X is implied). 218 ** pExpr->iTable Set to the cursor number for the table obtained 219 ** from pSrcList. 220 ** pExpr->y.pTab Points to the Table structure of X.Y (even if 221 ** X and/or Y are implied.) 222 ** pExpr->iColumn Set to the column number within the table. 223 ** pExpr->op Set to TK_COLUMN. 224 ** pExpr->pLeft Any expression this points to is deleted 225 ** pExpr->pRight Any expression this points to is deleted. 226 ** 227 ** The zDb variable is the name of the database (the "X"). This value may be 228 ** NULL meaning that name is of the form Y.Z or Z. Any available database 229 ** can be used. The zTable variable is the name of the table (the "Y"). This 230 ** value can be NULL if zDb is also NULL. If zTable is NULL it 231 ** means that the form of the name is Z and that columns from any table 232 ** can be used. 233 ** 234 ** If the name cannot be resolved unambiguously, leave an error message 235 ** in pParse and return WRC_Abort. Return WRC_Prune on success. 236 */ 237 static int lookupName( 238 Parse *pParse, /* The parsing context */ 239 const char *zDb, /* Name of the database containing table, or NULL */ 240 const char *zTab, /* Name of table containing column, or NULL */ 241 const char *zCol, /* Name of the column. */ 242 NameContext *pNC, /* The name context used to resolve the name */ 243 Expr *pExpr /* Make this EXPR node point to the selected column */ 244 ){ 245 int i, j; /* Loop counters */ 246 int cnt = 0; /* Number of matching column names */ 247 int cntTab = 0; /* Number of matching table names */ 248 int nSubquery = 0; /* How many levels of subquery */ 249 sqlite3 *db = pParse->db; /* The database connection */ 250 SrcItem *pItem; /* Use for looping over pSrcList items */ 251 SrcItem *pMatch = 0; /* The matching pSrcList item */ 252 NameContext *pTopNC = pNC; /* First namecontext in the list */ 253 Schema *pSchema = 0; /* Schema of the expression */ 254 int eNewExprOp = TK_COLUMN; /* New value for pExpr->op on success */ 255 Table *pTab = 0; /* Table hold the row */ 256 Column *pCol; /* A column of pTab */ 257 258 assert( pNC ); /* the name context cannot be NULL. */ 259 assert( zCol ); /* The Z in X.Y.Z cannot be NULL */ 260 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) ); 261 262 /* Initialize the node to no-match */ 263 pExpr->iTable = -1; 264 ExprSetVVAProperty(pExpr, EP_NoReduce); 265 266 /* Translate the schema name in zDb into a pointer to the corresponding 267 ** schema. If not found, pSchema will remain NULL and nothing will match 268 ** resulting in an appropriate error message toward the end of this routine 269 */ 270 if( zDb ){ 271 testcase( pNC->ncFlags & NC_PartIdx ); 272 testcase( pNC->ncFlags & NC_IsCheck ); 273 if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){ 274 /* Silently ignore database qualifiers inside CHECK constraints and 275 ** partial indices. Do not raise errors because that might break 276 ** legacy and because it does not hurt anything to just ignore the 277 ** database name. */ 278 zDb = 0; 279 }else{ 280 for(i=0; i<db->nDb; i++){ 281 assert( db->aDb[i].zDbSName ); 282 if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){ 283 pSchema = db->aDb[i].pSchema; 284 break; 285 } 286 } 287 if( i==db->nDb && sqlite3StrICmp("main", zDb)==0 ){ 288 /* This branch is taken when the main database has been renamed 289 ** using SQLITE_DBCONFIG_MAINDBNAME. */ 290 pSchema = db->aDb[0].pSchema; 291 zDb = db->aDb[0].zDbSName; 292 } 293 } 294 } 295 296 /* Start at the inner-most context and move outward until a match is found */ 297 assert( pNC && cnt==0 ); 298 do{ 299 ExprList *pEList; 300 SrcList *pSrcList = pNC->pSrcList; 301 302 if( pSrcList ){ 303 for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ 304 u8 hCol; 305 pTab = pItem->pTab; 306 assert( pTab!=0 && pTab->zName!=0 ); 307 assert( pTab->nCol>0 || pParse->nErr ); 308 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){ 309 int hit = 0; 310 pEList = pItem->pSelect->pEList; 311 for(j=0; j<pEList->nExpr; j++){ 312 if( sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){ 313 cnt++; 314 cntTab = 2; 315 pMatch = pItem; 316 pExpr->iColumn = j; 317 hit = 1; 318 } 319 } 320 if( hit || zTab==0 ) continue; 321 } 322 if( zDb ){ 323 if( pTab->pSchema!=pSchema ) continue; 324 if( pSchema==0 && strcmp(zDb,"*")!=0 ) continue; 325 } 326 if( zTab ){ 327 const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName; 328 assert( zTabName!=0 ); 329 if( sqlite3StrICmp(zTabName, zTab)!=0 ){ 330 continue; 331 } 332 assert( ExprUseYTab(pExpr) ); 333 if( IN_RENAME_OBJECT && pItem->zAlias ){ 334 sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab); 335 } 336 } 337 hCol = sqlite3StrIHash(zCol); 338 for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ 339 if( pCol->hName==hCol 340 && sqlite3StrICmp(pCol->zCnName, zCol)==0 341 ){ 342 /* If there has been exactly one prior match and this match 343 ** is for the right-hand table of a NATURAL JOIN or is in a 344 ** USING clause, then skip this match. 345 */ 346 if( cnt==1 ){ 347 if( pItem->fg.jointype & JT_NATURAL ) continue; 348 if( pItem->fg.isUsing 349 && nameInUsingClause(pItem->u3.pUsing, zCol) 350 ){ 351 continue; 352 } 353 } 354 cnt++; 355 pMatch = pItem; 356 /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ 357 pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j; 358 break; 359 } 360 } 361 if( 0==cnt && VisibleRowid(pTab) ){ 362 cntTab++; 363 pMatch = pItem; 364 } 365 } 366 if( pMatch ){ 367 pExpr->iTable = pMatch->iCursor; 368 assert( ExprUseYTab(pExpr) ); 369 pExpr->y.pTab = pMatch->pTab; 370 if( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 ){ 371 ExprSetProperty(pExpr, EP_CanBeNull); 372 } 373 pSchema = pExpr->y.pTab->pSchema; 374 } 375 } /* if( pSrcList ) */ 376 377 #if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) 378 /* If we have not already resolved the name, then maybe 379 ** it is a new.* or old.* trigger argument reference. Or 380 ** maybe it is an excluded.* from an upsert. Or maybe it is 381 ** a reference in the RETURNING clause to a table being modified. 382 */ 383 if( cnt==0 && zDb==0 ){ 384 pTab = 0; 385 #ifndef SQLITE_OMIT_TRIGGER 386 if( pParse->pTriggerTab!=0 ){ 387 int op = pParse->eTriggerOp; 388 assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT ); 389 if( pParse->bReturning ){ 390 if( (pNC->ncFlags & NC_UBaseReg)!=0 391 && (zTab==0 || sqlite3StrICmp(zTab,pParse->pTriggerTab->zName)==0) 392 ){ 393 pExpr->iTable = op!=TK_DELETE; 394 pTab = pParse->pTriggerTab; 395 } 396 }else if( op!=TK_DELETE && zTab && sqlite3StrICmp("new",zTab) == 0 ){ 397 pExpr->iTable = 1; 398 pTab = pParse->pTriggerTab; 399 }else if( op!=TK_INSERT && zTab && sqlite3StrICmp("old",zTab)==0 ){ 400 pExpr->iTable = 0; 401 pTab = pParse->pTriggerTab; 402 } 403 } 404 #endif /* SQLITE_OMIT_TRIGGER */ 405 #ifndef SQLITE_OMIT_UPSERT 406 if( (pNC->ncFlags & NC_UUpsert)!=0 && zTab!=0 ){ 407 Upsert *pUpsert = pNC->uNC.pUpsert; 408 if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){ 409 pTab = pUpsert->pUpsertSrc->a[0].pTab; 410 pExpr->iTable = EXCLUDED_TABLE_NUMBER; 411 } 412 } 413 #endif /* SQLITE_OMIT_UPSERT */ 414 415 if( pTab ){ 416 int iCol; 417 u8 hCol = sqlite3StrIHash(zCol); 418 pSchema = pTab->pSchema; 419 cntTab++; 420 for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){ 421 if( pCol->hName==hCol 422 && sqlite3StrICmp(pCol->zCnName, zCol)==0 423 ){ 424 if( iCol==pTab->iPKey ){ 425 iCol = -1; 426 } 427 break; 428 } 429 } 430 if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){ 431 /* IMP: R-51414-32910 */ 432 iCol = -1; 433 } 434 if( iCol<pTab->nCol ){ 435 cnt++; 436 pMatch = 0; 437 #ifndef SQLITE_OMIT_UPSERT 438 if( pExpr->iTable==EXCLUDED_TABLE_NUMBER ){ 439 testcase( iCol==(-1) ); 440 assert( ExprUseYTab(pExpr) ); 441 if( IN_RENAME_OBJECT ){ 442 pExpr->iColumn = iCol; 443 pExpr->y.pTab = pTab; 444 eNewExprOp = TK_COLUMN; 445 }else{ 446 pExpr->iTable = pNC->uNC.pUpsert->regData + 447 sqlite3TableColumnToStorage(pTab, iCol); 448 eNewExprOp = TK_REGISTER; 449 } 450 }else 451 #endif /* SQLITE_OMIT_UPSERT */ 452 { 453 assert( ExprUseYTab(pExpr) ); 454 pExpr->y.pTab = pTab; 455 if( pParse->bReturning ){ 456 eNewExprOp = TK_REGISTER; 457 pExpr->op2 = TK_COLUMN; 458 pExpr->iTable = pNC->uNC.iBaseReg + (pTab->nCol+1)*pExpr->iTable + 459 sqlite3TableColumnToStorage(pTab, iCol) + 1; 460 }else{ 461 pExpr->iColumn = (i16)iCol; 462 eNewExprOp = TK_TRIGGER; 463 #ifndef SQLITE_OMIT_TRIGGER 464 if( iCol<0 ){ 465 pExpr->affExpr = SQLITE_AFF_INTEGER; 466 }else if( pExpr->iTable==0 ){ 467 testcase( iCol==31 ); 468 testcase( iCol==32 ); 469 pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 470 }else{ 471 testcase( iCol==31 ); 472 testcase( iCol==32 ); 473 pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 474 } 475 #endif /* SQLITE_OMIT_TRIGGER */ 476 } 477 } 478 } 479 } 480 } 481 #endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */ 482 483 /* 484 ** Perhaps the name is a reference to the ROWID 485 */ 486 if( cnt==0 487 && cntTab==1 488 && pMatch 489 && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0 490 && sqlite3IsRowid(zCol) 491 && ALWAYS(VisibleRowid(pMatch->pTab)) 492 ){ 493 cnt = 1; 494 pExpr->iColumn = -1; 495 pExpr->affExpr = SQLITE_AFF_INTEGER; 496 } 497 498 /* 499 ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z 500 ** might refer to an result-set alias. This happens, for example, when 501 ** we are resolving names in the WHERE clause of the following command: 502 ** 503 ** SELECT a+b AS x FROM table WHERE x<10; 504 ** 505 ** In cases like this, replace pExpr with a copy of the expression that 506 ** forms the result set entry ("a+b" in the example) and return immediately. 507 ** Note that the expression in the result set should have already been 508 ** resolved by the time the WHERE clause is resolved. 509 ** 510 ** The ability to use an output result-set column in the WHERE, GROUP BY, 511 ** or HAVING clauses, or as part of a larger expression in the ORDER BY 512 ** clause is not standard SQL. This is a (goofy) SQLite extension, that 513 ** is supported for backwards compatibility only. Hence, we issue a warning 514 ** on sqlite3_log() whenever the capability is used. 515 */ 516 if( cnt==0 517 && (pNC->ncFlags & NC_UEList)!=0 518 && zTab==0 519 ){ 520 pEList = pNC->uNC.pEList; 521 assert( pEList!=0 ); 522 for(j=0; j<pEList->nExpr; j++){ 523 char *zAs = pEList->a[j].zEName; 524 if( pEList->a[j].eEName==ENAME_NAME 525 && sqlite3_stricmp(zAs, zCol)==0 526 ){ 527 Expr *pOrig; 528 assert( pExpr->pLeft==0 && pExpr->pRight==0 ); 529 assert( ExprUseXList(pExpr)==0 || pExpr->x.pList==0 ); 530 assert( ExprUseXSelect(pExpr)==0 || pExpr->x.pSelect==0 ); 531 pOrig = pEList->a[j].pExpr; 532 if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){ 533 sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs); 534 return WRC_Abort; 535 } 536 if( ExprHasProperty(pOrig, EP_Win) 537 && ((pNC->ncFlags&NC_AllowWin)==0 || pNC!=pTopNC ) 538 ){ 539 sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs); 540 return WRC_Abort; 541 } 542 if( sqlite3ExprVectorSize(pOrig)!=1 ){ 543 sqlite3ErrorMsg(pParse, "row value misused"); 544 return WRC_Abort; 545 } 546 resolveAlias(pParse, pEList, j, pExpr, nSubquery); 547 cnt = 1; 548 pMatch = 0; 549 assert( zTab==0 && zDb==0 ); 550 if( IN_RENAME_OBJECT ){ 551 sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr); 552 } 553 goto lookupname_end; 554 } 555 } 556 } 557 558 /* Advance to the next name context. The loop will exit when either 559 ** we have a match (cnt>0) or when we run out of name contexts. 560 */ 561 if( cnt ) break; 562 pNC = pNC->pNext; 563 nSubquery++; 564 }while( pNC ); 565 566 567 /* 568 ** If X and Y are NULL (in other words if only the column name Z is 569 ** supplied) and the value of Z is enclosed in double-quotes, then 570 ** Z is a string literal if it doesn't match any column names. In that 571 ** case, we need to return right away and not make any changes to 572 ** pExpr. 573 ** 574 ** Because no reference was made to outer contexts, the pNC->nRef 575 ** fields are not changed in any context. 576 */ 577 if( cnt==0 && zTab==0 ){ 578 assert( pExpr->op==TK_ID ); 579 if( ExprHasProperty(pExpr,EP_DblQuoted) 580 && areDoubleQuotedStringsEnabled(db, pTopNC) 581 ){ 582 /* If a double-quoted identifier does not match any known column name, 583 ** then treat it as a string. 584 ** 585 ** This hack was added in the early days of SQLite in a misguided attempt 586 ** to be compatible with MySQL 3.x, which used double-quotes for strings. 587 ** I now sorely regret putting in this hack. The effect of this hack is 588 ** that misspelled identifier names are silently converted into strings 589 ** rather than causing an error, to the frustration of countless 590 ** programmers. To all those frustrated programmers, my apologies. 591 ** 592 ** Someday, I hope to get rid of this hack. Unfortunately there is 593 ** a huge amount of legacy SQL that uses it. So for now, we just 594 ** issue a warning. 595 */ 596 sqlite3_log(SQLITE_WARNING, 597 "double-quoted string literal: \"%w\"", zCol); 598 #ifdef SQLITE_ENABLE_NORMALIZE 599 sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol); 600 #endif 601 pExpr->op = TK_STRING; 602 memset(&pExpr->y, 0, sizeof(pExpr->y)); 603 return WRC_Prune; 604 } 605 if( sqlite3ExprIdToTrueFalse(pExpr) ){ 606 return WRC_Prune; 607 } 608 } 609 610 /* 611 ** cnt==0 means there was not match. cnt>1 means there were two or 612 ** more matches. Either way, we have an error. 613 */ 614 if( cnt!=1 ){ 615 const char *zErr; 616 zErr = cnt==0 ? "no such column" : "ambiguous column name"; 617 if( zDb ){ 618 sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol); 619 }else if( zTab ){ 620 sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol); 621 }else{ 622 sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol); 623 } 624 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr); 625 pParse->checkSchema = 1; 626 pTopNC->nNcErr++; 627 } 628 629 /* If a column from a table in pSrcList is referenced, then record 630 ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes 631 ** bit 0 to be set. Column 1 sets bit 1. And so forth. Bit 63 is 632 ** set if the 63rd or any subsequent column is used. 633 ** 634 ** The colUsed mask is an optimization used to help determine if an 635 ** index is a covering index. The correct answer is still obtained 636 ** if the mask contains extra set bits. However, it is important to 637 ** avoid setting bits beyond the maximum column number of the table. 638 ** (See ticket [b92e5e8ec2cdbaa1]). 639 ** 640 ** If a generated column is referenced, set bits for every column 641 ** of the table. 642 */ 643 if( pExpr->iColumn>=0 && pMatch!=0 ){ 644 pMatch->colUsed |= sqlite3ExprColUsed(pExpr); 645 } 646 647 /* Clean up and return 648 */ 649 if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){ 650 sqlite3ExprDelete(db, pExpr->pLeft); 651 pExpr->pLeft = 0; 652 sqlite3ExprDelete(db, pExpr->pRight); 653 pExpr->pRight = 0; 654 } 655 pExpr->op = eNewExprOp; 656 ExprSetProperty(pExpr, EP_Leaf); 657 lookupname_end: 658 if( cnt==1 ){ 659 assert( pNC!=0 ); 660 #ifndef SQLITE_OMIT_AUTHORIZATION 661 if( pParse->db->xAuth 662 && (pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER) 663 ){ 664 sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); 665 } 666 #endif 667 /* Increment the nRef value on all name contexts from TopNC up to 668 ** the point where the name matched. */ 669 for(;;){ 670 assert( pTopNC!=0 ); 671 pTopNC->nRef++; 672 if( pTopNC==pNC ) break; 673 pTopNC = pTopNC->pNext; 674 } 675 return WRC_Prune; 676 } else { 677 return WRC_Abort; 678 } 679 } 680 681 /* 682 ** Allocate and return a pointer to an expression to load the column iCol 683 ** from datasource iSrc in SrcList pSrc. 684 */ 685 Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){ 686 Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0); 687 if( p ){ 688 SrcItem *pItem = &pSrc->a[iSrc]; 689 Table *pTab; 690 assert( ExprUseYTab(p) ); 691 pTab = p->y.pTab = pItem->pTab; 692 p->iTable = pItem->iCursor; 693 if( p->y.pTab->iPKey==iCol ){ 694 p->iColumn = -1; 695 }else{ 696 p->iColumn = (ynVar)iCol; 697 if( (pTab->tabFlags & TF_HasGenerated)!=0 698 && (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0 699 ){ 700 testcase( pTab->nCol==63 ); 701 testcase( pTab->nCol==64 ); 702 pItem->colUsed = pTab->nCol>=64 ? ALLBITS : MASKBIT(pTab->nCol)-1; 703 }else{ 704 testcase( iCol==BMS ); 705 testcase( iCol==BMS-1 ); 706 pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol); 707 } 708 } 709 } 710 return p; 711 } 712 713 /* 714 ** Report an error that an expression is not valid for some set of 715 ** pNC->ncFlags values determined by validMask. 716 ** 717 ** static void notValid( 718 ** Parse *pParse, // Leave error message here 719 ** NameContext *pNC, // The name context 720 ** const char *zMsg, // Type of error 721 ** int validMask, // Set of contexts for which prohibited 722 ** Expr *pExpr // Invalidate this expression on error 723 ** ){...} 724 ** 725 ** As an optimization, since the conditional is almost always false 726 ** (because errors are rare), the conditional is moved outside of the 727 ** function call using a macro. 728 */ 729 static void notValidImpl( 730 Parse *pParse, /* Leave error message here */ 731 NameContext *pNC, /* The name context */ 732 const char *zMsg, /* Type of error */ 733 Expr *pExpr, /* Invalidate this expression on error */ 734 Expr *pError /* Associate error with this expression */ 735 ){ 736 const char *zIn = "partial index WHERE clauses"; 737 if( pNC->ncFlags & NC_IdxExpr ) zIn = "index expressions"; 738 #ifndef SQLITE_OMIT_CHECK 739 else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints"; 740 #endif 741 #ifndef SQLITE_OMIT_GENERATED_COLUMNS 742 else if( pNC->ncFlags & NC_GenCol ) zIn = "generated columns"; 743 #endif 744 sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn); 745 if( pExpr ) pExpr->op = TK_NULL; 746 sqlite3RecordErrorOffsetOfExpr(pParse->db, pError); 747 } 748 #define sqlite3ResolveNotValid(P,N,M,X,E,R) \ 749 assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \ 750 if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E,R); 751 752 /* 753 ** Expression p should encode a floating point value between 1.0 and 0.0. 754 ** Return 1024 times this value. Or return -1 if p is not a floating point 755 ** value between 1.0 and 0.0. 756 */ 757 static int exprProbability(Expr *p){ 758 double r = -1.0; 759 if( p->op!=TK_FLOAT ) return -1; 760 assert( !ExprHasProperty(p, EP_IntValue) ); 761 sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8); 762 assert( r>=0.0 ); 763 if( r>1.0 ) return -1; 764 return (int)(r*134217728.0); 765 } 766 767 /* 768 ** This routine is callback for sqlite3WalkExpr(). 769 ** 770 ** Resolve symbolic names into TK_COLUMN operators for the current 771 ** node in the expression tree. Return 0 to continue the search down 772 ** the tree or 2 to abort the tree walk. 773 ** 774 ** This routine also does error checking and name resolution for 775 ** function names. The operator for aggregate functions is changed 776 ** to TK_AGG_FUNCTION. 777 */ 778 static int resolveExprStep(Walker *pWalker, Expr *pExpr){ 779 NameContext *pNC; 780 Parse *pParse; 781 782 pNC = pWalker->u.pNC; 783 assert( pNC!=0 ); 784 pParse = pNC->pParse; 785 assert( pParse==pWalker->pParse ); 786 787 #ifndef NDEBUG 788 if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ 789 SrcList *pSrcList = pNC->pSrcList; 790 int i; 791 for(i=0; i<pNC->pSrcList->nSrc; i++){ 792 assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); 793 } 794 } 795 #endif 796 switch( pExpr->op ){ 797 798 /* The special operator TK_ROW means use the rowid for the first 799 ** column in the FROM clause. This is used by the LIMIT and ORDER BY 800 ** clause processing on UPDATE and DELETE statements, and by 801 ** UPDATE ... FROM statement processing. 802 */ 803 case TK_ROW: { 804 SrcList *pSrcList = pNC->pSrcList; 805 SrcItem *pItem; 806 assert( pSrcList && pSrcList->nSrc>=1 ); 807 pItem = pSrcList->a; 808 pExpr->op = TK_COLUMN; 809 assert( ExprUseYTab(pExpr) ); 810 pExpr->y.pTab = pItem->pTab; 811 pExpr->iTable = pItem->iCursor; 812 pExpr->iColumn--; 813 pExpr->affExpr = SQLITE_AFF_INTEGER; 814 break; 815 } 816 817 /* An optimization: Attempt to convert 818 ** 819 ** "expr IS NOT NULL" --> "TRUE" 820 ** "expr IS NULL" --> "FALSE" 821 ** 822 ** if we can prove that "expr" is never NULL. Call this the 823 ** "NOT NULL strength reduction optimization". 824 ** 825 ** If this optimization occurs, also restore the NameContext ref-counts 826 ** to the state they where in before the "column" LHS expression was 827 ** resolved. This prevents "column" from being counted as having been 828 ** referenced, which might prevent a SELECT from being erroneously 829 ** marked as correlated. 830 */ 831 case TK_NOTNULL: 832 case TK_ISNULL: { 833 int anRef[8]; 834 NameContext *p; 835 int i; 836 for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ 837 anRef[i] = p->nRef; 838 } 839 sqlite3WalkExpr(pWalker, pExpr->pLeft); 840 if( 0==sqlite3ExprCanBeNull(pExpr->pLeft) && !IN_RENAME_OBJECT ){ 841 testcase( ExprHasProperty(pExpr, EP_FromJoin) ); 842 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 843 if( pExpr->op==TK_NOTNULL ){ 844 pExpr->u.zToken = "true"; 845 ExprSetProperty(pExpr, EP_IsTrue); 846 }else{ 847 pExpr->u.zToken = "false"; 848 ExprSetProperty(pExpr, EP_IsFalse); 849 } 850 pExpr->op = TK_TRUEFALSE; 851 for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ 852 p->nRef = anRef[i]; 853 } 854 sqlite3ExprDelete(pParse->db, pExpr->pLeft); 855 pExpr->pLeft = 0; 856 } 857 return WRC_Prune; 858 } 859 860 /* A column name: ID 861 ** Or table name and column name: ID.ID 862 ** Or a database, table and column: ID.ID.ID 863 ** 864 ** The TK_ID and TK_OUT cases are combined so that there will only 865 ** be one call to lookupName(). Then the compiler will in-line 866 ** lookupName() for a size reduction and performance increase. 867 */ 868 case TK_ID: 869 case TK_DOT: { 870 const char *zColumn; 871 const char *zTable; 872 const char *zDb; 873 Expr *pRight; 874 875 if( pExpr->op==TK_ID ){ 876 zDb = 0; 877 zTable = 0; 878 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 879 zColumn = pExpr->u.zToken; 880 }else{ 881 Expr *pLeft = pExpr->pLeft; 882 testcase( pNC->ncFlags & NC_IdxExpr ); 883 testcase( pNC->ncFlags & NC_GenCol ); 884 sqlite3ResolveNotValid(pParse, pNC, "the \".\" operator", 885 NC_IdxExpr|NC_GenCol, 0, pExpr); 886 pRight = pExpr->pRight; 887 if( pRight->op==TK_ID ){ 888 zDb = 0; 889 }else{ 890 assert( pRight->op==TK_DOT ); 891 assert( !ExprHasProperty(pRight, EP_IntValue) ); 892 zDb = pLeft->u.zToken; 893 pLeft = pRight->pLeft; 894 pRight = pRight->pRight; 895 } 896 assert( ExprUseUToken(pLeft) && ExprUseUToken(pRight) ); 897 zTable = pLeft->u.zToken; 898 zColumn = pRight->u.zToken; 899 assert( ExprUseYTab(pExpr) ); 900 if( IN_RENAME_OBJECT ){ 901 sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight); 902 sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft); 903 } 904 } 905 return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr); 906 } 907 908 /* Resolve function names 909 */ 910 case TK_FUNCTION: { 911 ExprList *pList = pExpr->x.pList; /* The argument list */ 912 int n = pList ? pList->nExpr : 0; /* Number of arguments */ 913 int no_such_func = 0; /* True if no such function exists */ 914 int wrong_num_args = 0; /* True if wrong number of arguments */ 915 int is_agg = 0; /* True if is an aggregate function */ 916 const char *zId; /* The function name. */ 917 FuncDef *pDef; /* Information about the function */ 918 u8 enc = ENC(pParse->db); /* The database encoding */ 919 int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin)); 920 #ifndef SQLITE_OMIT_WINDOWFUNC 921 Window *pWin = (IsWindowFunc(pExpr) ? pExpr->y.pWin : 0); 922 #endif 923 assert( !ExprHasProperty(pExpr, EP_xIsSelect|EP_IntValue) ); 924 zId = pExpr->u.zToken; 925 pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0); 926 if( pDef==0 ){ 927 pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0); 928 if( pDef==0 ){ 929 no_such_func = 1; 930 }else{ 931 wrong_num_args = 1; 932 } 933 }else{ 934 is_agg = pDef->xFinalize!=0; 935 if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){ 936 ExprSetProperty(pExpr, EP_Unlikely); 937 if( n==2 ){ 938 pExpr->iTable = exprProbability(pList->a[1].pExpr); 939 if( pExpr->iTable<0 ){ 940 sqlite3ErrorMsg(pParse, 941 "second argument to %#T() must be a " 942 "constant between 0.0 and 1.0", pExpr); 943 pNC->nNcErr++; 944 } 945 }else{ 946 /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is 947 ** equivalent to likelihood(X, 0.0625). 948 ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is 949 ** short-hand for likelihood(X,0.0625). 950 ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand 951 ** for likelihood(X,0.9375). 952 ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent 953 ** to likelihood(X,0.9375). */ 954 /* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */ 955 pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120; 956 } 957 } 958 #ifndef SQLITE_OMIT_AUTHORIZATION 959 { 960 int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0); 961 if( auth!=SQLITE_OK ){ 962 if( auth==SQLITE_DENY ){ 963 sqlite3ErrorMsg(pParse, "not authorized to use function: %#T", 964 pExpr); 965 pNC->nNcErr++; 966 } 967 pExpr->op = TK_NULL; 968 return WRC_Prune; 969 } 970 } 971 #endif 972 if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){ 973 /* For the purposes of the EP_ConstFunc flag, date and time 974 ** functions and other functions that change slowly are considered 975 ** constant because they are constant for the duration of one query. 976 ** This allows them to be factored out of inner loops. */ 977 ExprSetProperty(pExpr,EP_ConstFunc); 978 } 979 if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){ 980 /* Clearly non-deterministic functions like random(), but also 981 ** date/time functions that use 'now', and other functions like 982 ** sqlite_version() that might change over time cannot be used 983 ** in an index or generated column. Curiously, they can be used 984 ** in a CHECK constraint. SQLServer, MySQL, and PostgreSQL all 985 ** all this. */ 986 sqlite3ResolveNotValid(pParse, pNC, "non-deterministic functions", 987 NC_IdxExpr|NC_PartIdx|NC_GenCol, 0, pExpr); 988 }else{ 989 assert( (NC_SelfRef & 0xff)==NC_SelfRef ); /* Must fit in 8 bits */ 990 pExpr->op2 = pNC->ncFlags & NC_SelfRef; 991 if( pNC->ncFlags & NC_FromDDL ) ExprSetProperty(pExpr, EP_FromDDL); 992 } 993 if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0 994 && pParse->nested==0 995 && (pParse->db->mDbFlags & DBFLAG_InternalFunc)==0 996 ){ 997 /* Internal-use-only functions are disallowed unless the 998 ** SQL is being compiled using sqlite3NestedParse() or 999 ** the SQLITE_TESTCTRL_INTERNAL_FUNCTIONS test-control has be 1000 ** used to activate internal functions for testing purposes */ 1001 no_such_func = 1; 1002 pDef = 0; 1003 }else 1004 if( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 1005 && !IN_RENAME_OBJECT 1006 ){ 1007 sqlite3ExprFunctionUsable(pParse, pExpr, pDef); 1008 } 1009 } 1010 1011 if( 0==IN_RENAME_OBJECT ){ 1012 #ifndef SQLITE_OMIT_WINDOWFUNC 1013 assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX) 1014 || (pDef->xValue==0 && pDef->xInverse==0) 1015 || (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize) 1016 ); 1017 if( pDef && pDef->xValue==0 && pWin ){ 1018 sqlite3ErrorMsg(pParse, 1019 "%#T() may not be used as a window function", pExpr 1020 ); 1021 pNC->nNcErr++; 1022 }else if( 1023 (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) 1024 || (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pWin) 1025 || (is_agg && pWin && (pNC->ncFlags & NC_AllowWin)==0) 1026 ){ 1027 const char *zType; 1028 if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pWin ){ 1029 zType = "window"; 1030 }else{ 1031 zType = "aggregate"; 1032 } 1033 sqlite3ErrorMsg(pParse, "misuse of %s function %#T()",zType,pExpr); 1034 pNC->nNcErr++; 1035 is_agg = 0; 1036 } 1037 #else 1038 if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){ 1039 sqlite3ErrorMsg(pParse,"misuse of aggregate function %#T()",pExpr); 1040 pNC->nNcErr++; 1041 is_agg = 0; 1042 } 1043 #endif 1044 else if( no_such_func && pParse->db->init.busy==0 1045 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION 1046 && pParse->explain==0 1047 #endif 1048 ){ 1049 sqlite3ErrorMsg(pParse, "no such function: %#T", pExpr); 1050 pNC->nNcErr++; 1051 }else if( wrong_num_args ){ 1052 sqlite3ErrorMsg(pParse,"wrong number of arguments to function %#T()", 1053 pExpr); 1054 pNC->nNcErr++; 1055 } 1056 #ifndef SQLITE_OMIT_WINDOWFUNC 1057 else if( is_agg==0 && ExprHasProperty(pExpr, EP_WinFunc) ){ 1058 sqlite3ErrorMsg(pParse, 1059 "FILTER may not be used with non-aggregate %#T()", 1060 pExpr 1061 ); 1062 pNC->nNcErr++; 1063 } 1064 #endif 1065 if( is_agg ){ 1066 /* Window functions may not be arguments of aggregate functions. 1067 ** Or arguments of other window functions. But aggregate functions 1068 ** may be arguments for window functions. */ 1069 #ifndef SQLITE_OMIT_WINDOWFUNC 1070 pNC->ncFlags &= ~(NC_AllowWin | (!pWin ? NC_AllowAgg : 0)); 1071 #else 1072 pNC->ncFlags &= ~NC_AllowAgg; 1073 #endif 1074 } 1075 } 1076 #ifndef SQLITE_OMIT_WINDOWFUNC 1077 else if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1078 is_agg = 1; 1079 } 1080 #endif 1081 sqlite3WalkExprList(pWalker, pList); 1082 if( is_agg ){ 1083 #ifndef SQLITE_OMIT_WINDOWFUNC 1084 if( pWin ){ 1085 Select *pSel = pNC->pWinSelect; 1086 assert( pWin==0 || (ExprUseYWin(pExpr) && pWin==pExpr->y.pWin) ); 1087 if( IN_RENAME_OBJECT==0 ){ 1088 sqlite3WindowUpdate(pParse, pSel ? pSel->pWinDefn : 0, pWin, pDef); 1089 if( pParse->db->mallocFailed ) break; 1090 } 1091 sqlite3WalkExprList(pWalker, pWin->pPartition); 1092 sqlite3WalkExprList(pWalker, pWin->pOrderBy); 1093 sqlite3WalkExpr(pWalker, pWin->pFilter); 1094 sqlite3WindowLink(pSel, pWin); 1095 pNC->ncFlags |= NC_HasWin; 1096 }else 1097 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1098 { 1099 NameContext *pNC2; /* For looping up thru outer contexts */ 1100 pExpr->op = TK_AGG_FUNCTION; 1101 pExpr->op2 = 0; 1102 #ifndef SQLITE_OMIT_WINDOWFUNC 1103 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1104 sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter); 1105 } 1106 #endif 1107 pNC2 = pNC; 1108 while( pNC2 1109 && sqlite3ReferencesSrcList(pParse, pExpr, pNC2->pSrcList)==0 1110 ){ 1111 pExpr->op2++; 1112 pNC2 = pNC2->pNext; 1113 } 1114 assert( pDef!=0 || IN_RENAME_OBJECT ); 1115 if( pNC2 && pDef ){ 1116 assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg ); 1117 assert( SQLITE_FUNC_ANYORDER==NC_OrderAgg ); 1118 testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 ); 1119 testcase( (pDef->funcFlags & SQLITE_FUNC_ANYORDER)!=0 ); 1120 pNC2->ncFlags |= NC_HasAgg 1121 | ((pDef->funcFlags^SQLITE_FUNC_ANYORDER) 1122 & (SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER)); 1123 } 1124 } 1125 pNC->ncFlags |= savedAllowFlags; 1126 } 1127 /* FIX ME: Compute pExpr->affinity based on the expected return 1128 ** type of the function 1129 */ 1130 return WRC_Prune; 1131 } 1132 #ifndef SQLITE_OMIT_SUBQUERY 1133 case TK_SELECT: 1134 case TK_EXISTS: testcase( pExpr->op==TK_EXISTS ); 1135 #endif 1136 case TK_IN: { 1137 testcase( pExpr->op==TK_IN ); 1138 if( ExprUseXSelect(pExpr) ){ 1139 int nRef = pNC->nRef; 1140 testcase( pNC->ncFlags & NC_IsCheck ); 1141 testcase( pNC->ncFlags & NC_PartIdx ); 1142 testcase( pNC->ncFlags & NC_IdxExpr ); 1143 testcase( pNC->ncFlags & NC_GenCol ); 1144 if( pNC->ncFlags & NC_SelfRef ){ 1145 notValidImpl(pParse, pNC, "subqueries", pExpr, pExpr); 1146 }else{ 1147 sqlite3WalkSelect(pWalker, pExpr->x.pSelect); 1148 } 1149 assert( pNC->nRef>=nRef ); 1150 if( nRef!=pNC->nRef ){ 1151 ExprSetProperty(pExpr, EP_VarSelect); 1152 pNC->ncFlags |= NC_VarSelect; 1153 } 1154 } 1155 break; 1156 } 1157 case TK_VARIABLE: { 1158 testcase( pNC->ncFlags & NC_IsCheck ); 1159 testcase( pNC->ncFlags & NC_PartIdx ); 1160 testcase( pNC->ncFlags & NC_IdxExpr ); 1161 testcase( pNC->ncFlags & NC_GenCol ); 1162 sqlite3ResolveNotValid(pParse, pNC, "parameters", 1163 NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol, pExpr, pExpr); 1164 break; 1165 } 1166 case TK_IS: 1167 case TK_ISNOT: { 1168 Expr *pRight = sqlite3ExprSkipCollateAndLikely(pExpr->pRight); 1169 assert( !ExprHasProperty(pExpr, EP_Reduced) ); 1170 /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE", 1171 ** and "x IS NOT FALSE". */ 1172 if( ALWAYS(pRight) && (pRight->op==TK_ID || pRight->op==TK_TRUEFALSE) ){ 1173 int rc = resolveExprStep(pWalker, pRight); 1174 if( rc==WRC_Abort ) return WRC_Abort; 1175 if( pRight->op==TK_TRUEFALSE ){ 1176 pExpr->op2 = pExpr->op; 1177 pExpr->op = TK_TRUTH; 1178 return WRC_Continue; 1179 } 1180 } 1181 /* no break */ deliberate_fall_through 1182 } 1183 case TK_BETWEEN: 1184 case TK_EQ: 1185 case TK_NE: 1186 case TK_LT: 1187 case TK_LE: 1188 case TK_GT: 1189 case TK_GE: { 1190 int nLeft, nRight; 1191 if( pParse->db->mallocFailed ) break; 1192 assert( pExpr->pLeft!=0 ); 1193 nLeft = sqlite3ExprVectorSize(pExpr->pLeft); 1194 if( pExpr->op==TK_BETWEEN ){ 1195 assert( ExprUseXList(pExpr) ); 1196 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr); 1197 if( nRight==nLeft ){ 1198 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr); 1199 } 1200 }else{ 1201 assert( pExpr->pRight!=0 ); 1202 nRight = sqlite3ExprVectorSize(pExpr->pRight); 1203 } 1204 if( nLeft!=nRight ){ 1205 testcase( pExpr->op==TK_EQ ); 1206 testcase( pExpr->op==TK_NE ); 1207 testcase( pExpr->op==TK_LT ); 1208 testcase( pExpr->op==TK_LE ); 1209 testcase( pExpr->op==TK_GT ); 1210 testcase( pExpr->op==TK_GE ); 1211 testcase( pExpr->op==TK_IS ); 1212 testcase( pExpr->op==TK_ISNOT ); 1213 testcase( pExpr->op==TK_BETWEEN ); 1214 sqlite3ErrorMsg(pParse, "row value misused"); 1215 sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr); 1216 } 1217 break; 1218 } 1219 } 1220 assert( pParse->db->mallocFailed==0 || pParse->nErr!=0 ); 1221 return pParse->nErr ? WRC_Abort : WRC_Continue; 1222 } 1223 1224 /* 1225 ** pEList is a list of expressions which are really the result set of the 1226 ** a SELECT statement. pE is a term in an ORDER BY or GROUP BY clause. 1227 ** This routine checks to see if pE is a simple identifier which corresponds 1228 ** to the AS-name of one of the terms of the expression list. If it is, 1229 ** this routine return an integer between 1 and N where N is the number of 1230 ** elements in pEList, corresponding to the matching entry. If there is 1231 ** no match, or if pE is not a simple identifier, then this routine 1232 ** return 0. 1233 ** 1234 ** pEList has been resolved. pE has not. 1235 */ 1236 static int resolveAsName( 1237 Parse *pParse, /* Parsing context for error messages */ 1238 ExprList *pEList, /* List of expressions to scan */ 1239 Expr *pE /* Expression we are trying to match */ 1240 ){ 1241 int i; /* Loop counter */ 1242 1243 UNUSED_PARAMETER(pParse); 1244 1245 if( pE->op==TK_ID ){ 1246 const char *zCol; 1247 assert( !ExprHasProperty(pE, EP_IntValue) ); 1248 zCol = pE->u.zToken; 1249 for(i=0; i<pEList->nExpr; i++){ 1250 if( pEList->a[i].eEName==ENAME_NAME 1251 && sqlite3_stricmp(pEList->a[i].zEName, zCol)==0 1252 ){ 1253 return i+1; 1254 } 1255 } 1256 } 1257 return 0; 1258 } 1259 1260 /* 1261 ** pE is a pointer to an expression which is a single term in the 1262 ** ORDER BY of a compound SELECT. The expression has not been 1263 ** name resolved. 1264 ** 1265 ** At the point this routine is called, we already know that the 1266 ** ORDER BY term is not an integer index into the result set. That 1267 ** case is handled by the calling routine. 1268 ** 1269 ** Attempt to match pE against result set columns in the left-most 1270 ** SELECT statement. Return the index i of the matching column, 1271 ** as an indication to the caller that it should sort by the i-th column. 1272 ** The left-most column is 1. In other words, the value returned is the 1273 ** same integer value that would be used in the SQL statement to indicate 1274 ** the column. 1275 ** 1276 ** If there is no match, return 0. Return -1 if an error occurs. 1277 */ 1278 static int resolveOrderByTermToExprList( 1279 Parse *pParse, /* Parsing context for error messages */ 1280 Select *pSelect, /* The SELECT statement with the ORDER BY clause */ 1281 Expr *pE /* The specific ORDER BY term */ 1282 ){ 1283 int i; /* Loop counter */ 1284 ExprList *pEList; /* The columns of the result set */ 1285 NameContext nc; /* Name context for resolving pE */ 1286 sqlite3 *db; /* Database connection */ 1287 int rc; /* Return code from subprocedures */ 1288 u8 savedSuppErr; /* Saved value of db->suppressErr */ 1289 1290 assert( sqlite3ExprIsInteger(pE, &i)==0 ); 1291 pEList = pSelect->pEList; 1292 1293 /* Resolve all names in the ORDER BY term expression 1294 */ 1295 memset(&nc, 0, sizeof(nc)); 1296 nc.pParse = pParse; 1297 nc.pSrcList = pSelect->pSrc; 1298 nc.uNC.pEList = pEList; 1299 nc.ncFlags = NC_AllowAgg|NC_UEList|NC_NoSelect; 1300 nc.nNcErr = 0; 1301 db = pParse->db; 1302 savedSuppErr = db->suppressErr; 1303 db->suppressErr = 1; 1304 rc = sqlite3ResolveExprNames(&nc, pE); 1305 db->suppressErr = savedSuppErr; 1306 if( rc ) return 0; 1307 1308 /* Try to match the ORDER BY expression against an expression 1309 ** in the result set. Return an 1-based index of the matching 1310 ** result-set entry. 1311 */ 1312 for(i=0; i<pEList->nExpr; i++){ 1313 if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){ 1314 return i+1; 1315 } 1316 } 1317 1318 /* If no match, return 0. */ 1319 return 0; 1320 } 1321 1322 /* 1323 ** Generate an ORDER BY or GROUP BY term out-of-range error. 1324 */ 1325 static void resolveOutOfRangeError( 1326 Parse *pParse, /* The error context into which to write the error */ 1327 const char *zType, /* "ORDER" or "GROUP" */ 1328 int i, /* The index (1-based) of the term out of range */ 1329 int mx, /* Largest permissible value of i */ 1330 Expr *pError /* Associate the error with the expression */ 1331 ){ 1332 sqlite3ErrorMsg(pParse, 1333 "%r %s BY term out of range - should be " 1334 "between 1 and %d", i, zType, mx); 1335 sqlite3RecordErrorOffsetOfExpr(pParse->db, pError); 1336 } 1337 1338 /* 1339 ** Analyze the ORDER BY clause in a compound SELECT statement. Modify 1340 ** each term of the ORDER BY clause is a constant integer between 1 1341 ** and N where N is the number of columns in the compound SELECT. 1342 ** 1343 ** ORDER BY terms that are already an integer between 1 and N are 1344 ** unmodified. ORDER BY terms that are integers outside the range of 1345 ** 1 through N generate an error. ORDER BY terms that are expressions 1346 ** are matched against result set expressions of compound SELECT 1347 ** beginning with the left-most SELECT and working toward the right. 1348 ** At the first match, the ORDER BY expression is transformed into 1349 ** the integer column number. 1350 ** 1351 ** Return the number of errors seen. 1352 */ 1353 static int resolveCompoundOrderBy( 1354 Parse *pParse, /* Parsing context. Leave error messages here */ 1355 Select *pSelect /* The SELECT statement containing the ORDER BY */ 1356 ){ 1357 int i; 1358 ExprList *pOrderBy; 1359 ExprList *pEList; 1360 sqlite3 *db; 1361 int moreToDo = 1; 1362 1363 pOrderBy = pSelect->pOrderBy; 1364 if( pOrderBy==0 ) return 0; 1365 db = pParse->db; 1366 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1367 sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause"); 1368 return 1; 1369 } 1370 for(i=0; i<pOrderBy->nExpr; i++){ 1371 pOrderBy->a[i].done = 0; 1372 } 1373 pSelect->pNext = 0; 1374 while( pSelect->pPrior ){ 1375 pSelect->pPrior->pNext = pSelect; 1376 pSelect = pSelect->pPrior; 1377 } 1378 while( pSelect && moreToDo ){ 1379 struct ExprList_item *pItem; 1380 moreToDo = 0; 1381 pEList = pSelect->pEList; 1382 assert( pEList!=0 ); 1383 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1384 int iCol = -1; 1385 Expr *pE, *pDup; 1386 if( pItem->done ) continue; 1387 pE = sqlite3ExprSkipCollateAndLikely(pItem->pExpr); 1388 if( NEVER(pE==0) ) continue; 1389 if( sqlite3ExprIsInteger(pE, &iCol) ){ 1390 if( iCol<=0 || iCol>pEList->nExpr ){ 1391 resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr, pE); 1392 return 1; 1393 } 1394 }else{ 1395 iCol = resolveAsName(pParse, pEList, pE); 1396 if( iCol==0 ){ 1397 /* Now test if expression pE matches one of the values returned 1398 ** by pSelect. In the usual case this is done by duplicating the 1399 ** expression, resolving any symbols in it, and then comparing 1400 ** it against each expression returned by the SELECT statement. 1401 ** Once the comparisons are finished, the duplicate expression 1402 ** is deleted. 1403 ** 1404 ** If this is running as part of an ALTER TABLE operation and 1405 ** the symbols resolve successfully, also resolve the symbols in the 1406 ** actual expression. This allows the code in alter.c to modify 1407 ** column references within the ORDER BY expression as required. */ 1408 pDup = sqlite3ExprDup(db, pE, 0); 1409 if( !db->mallocFailed ){ 1410 assert(pDup); 1411 iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup); 1412 if( IN_RENAME_OBJECT && iCol>0 ){ 1413 resolveOrderByTermToExprList(pParse, pSelect, pE); 1414 } 1415 } 1416 sqlite3ExprDelete(db, pDup); 1417 } 1418 } 1419 if( iCol>0 ){ 1420 /* Convert the ORDER BY term into an integer column number iCol, 1421 ** taking care to preserve the COLLATE clause if it exists. */ 1422 if( !IN_RENAME_OBJECT ){ 1423 Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); 1424 if( pNew==0 ) return 1; 1425 pNew->flags |= EP_IntValue; 1426 pNew->u.iValue = iCol; 1427 if( pItem->pExpr==pE ){ 1428 pItem->pExpr = pNew; 1429 }else{ 1430 Expr *pParent = pItem->pExpr; 1431 assert( pParent->op==TK_COLLATE ); 1432 while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft; 1433 assert( pParent->pLeft==pE ); 1434 pParent->pLeft = pNew; 1435 } 1436 sqlite3ExprDelete(db, pE); 1437 pItem->u.x.iOrderByCol = (u16)iCol; 1438 } 1439 pItem->done = 1; 1440 }else{ 1441 moreToDo = 1; 1442 } 1443 } 1444 pSelect = pSelect->pNext; 1445 } 1446 for(i=0; i<pOrderBy->nExpr; i++){ 1447 if( pOrderBy->a[i].done==0 ){ 1448 sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any " 1449 "column in the result set", i+1); 1450 return 1; 1451 } 1452 } 1453 return 0; 1454 } 1455 1456 /* 1457 ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of 1458 ** the SELECT statement pSelect. If any term is reference to a 1459 ** result set expression (as determined by the ExprList.a.u.x.iOrderByCol 1460 ** field) then convert that term into a copy of the corresponding result set 1461 ** column. 1462 ** 1463 ** If any errors are detected, add an error message to pParse and 1464 ** return non-zero. Return zero if no errors are seen. 1465 */ 1466 int sqlite3ResolveOrderGroupBy( 1467 Parse *pParse, /* Parsing context. Leave error messages here */ 1468 Select *pSelect, /* The SELECT statement containing the clause */ 1469 ExprList *pOrderBy, /* The ORDER BY or GROUP BY clause to be processed */ 1470 const char *zType /* "ORDER" or "GROUP" */ 1471 ){ 1472 int i; 1473 sqlite3 *db = pParse->db; 1474 ExprList *pEList; 1475 struct ExprList_item *pItem; 1476 1477 if( pOrderBy==0 || pParse->db->mallocFailed || IN_RENAME_OBJECT ) return 0; 1478 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1479 sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType); 1480 return 1; 1481 } 1482 pEList = pSelect->pEList; 1483 assert( pEList!=0 ); /* sqlite3SelectNew() guarantees this */ 1484 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1485 if( pItem->u.x.iOrderByCol ){ 1486 if( pItem->u.x.iOrderByCol>pEList->nExpr ){ 1487 resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr, 0); 1488 return 1; 1489 } 1490 resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,0); 1491 } 1492 } 1493 return 0; 1494 } 1495 1496 #ifndef SQLITE_OMIT_WINDOWFUNC 1497 /* 1498 ** Walker callback for windowRemoveExprFromSelect(). 1499 */ 1500 static int resolveRemoveWindowsCb(Walker *pWalker, Expr *pExpr){ 1501 UNUSED_PARAMETER(pWalker); 1502 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1503 Window *pWin = pExpr->y.pWin; 1504 sqlite3WindowUnlinkFromSelect(pWin); 1505 } 1506 return WRC_Continue; 1507 } 1508 1509 /* 1510 ** Remove any Window objects owned by the expression pExpr from the 1511 ** Select.pWin list of Select object pSelect. 1512 */ 1513 static void windowRemoveExprFromSelect(Select *pSelect, Expr *pExpr){ 1514 if( pSelect->pWin ){ 1515 Walker sWalker; 1516 memset(&sWalker, 0, sizeof(Walker)); 1517 sWalker.xExprCallback = resolveRemoveWindowsCb; 1518 sWalker.u.pSelect = pSelect; 1519 sqlite3WalkExpr(&sWalker, pExpr); 1520 } 1521 } 1522 #else 1523 # define windowRemoveExprFromSelect(a, b) 1524 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1525 1526 /* 1527 ** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect. 1528 ** The Name context of the SELECT statement is pNC. zType is either 1529 ** "ORDER" or "GROUP" depending on which type of clause pOrderBy is. 1530 ** 1531 ** This routine resolves each term of the clause into an expression. 1532 ** If the order-by term is an integer I between 1 and N (where N is the 1533 ** number of columns in the result set of the SELECT) then the expression 1534 ** in the resolution is a copy of the I-th result-set expression. If 1535 ** the order-by term is an identifier that corresponds to the AS-name of 1536 ** a result-set expression, then the term resolves to a copy of the 1537 ** result-set expression. Otherwise, the expression is resolved in 1538 ** the usual way - using sqlite3ResolveExprNames(). 1539 ** 1540 ** This routine returns the number of errors. If errors occur, then 1541 ** an appropriate error message might be left in pParse. (OOM errors 1542 ** excepted.) 1543 */ 1544 static int resolveOrderGroupBy( 1545 NameContext *pNC, /* The name context of the SELECT statement */ 1546 Select *pSelect, /* The SELECT statement holding pOrderBy */ 1547 ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */ 1548 const char *zType /* Either "ORDER" or "GROUP", as appropriate */ 1549 ){ 1550 int i, j; /* Loop counters */ 1551 int iCol; /* Column number */ 1552 struct ExprList_item *pItem; /* A term of the ORDER BY clause */ 1553 Parse *pParse; /* Parsing context */ 1554 int nResult; /* Number of terms in the result set */ 1555 1556 assert( pOrderBy!=0 ); 1557 nResult = pSelect->pEList->nExpr; 1558 pParse = pNC->pParse; 1559 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1560 Expr *pE = pItem->pExpr; 1561 Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pE); 1562 if( NEVER(pE2==0) ) continue; 1563 if( zType[0]!='G' ){ 1564 iCol = resolveAsName(pParse, pSelect->pEList, pE2); 1565 if( iCol>0 ){ 1566 /* If an AS-name match is found, mark this ORDER BY column as being 1567 ** a copy of the iCol-th result-set column. The subsequent call to 1568 ** sqlite3ResolveOrderGroupBy() will convert the expression to a 1569 ** copy of the iCol-th result-set expression. */ 1570 pItem->u.x.iOrderByCol = (u16)iCol; 1571 continue; 1572 } 1573 } 1574 if( sqlite3ExprIsInteger(pE2, &iCol) ){ 1575 /* The ORDER BY term is an integer constant. Again, set the column 1576 ** number so that sqlite3ResolveOrderGroupBy() will convert the 1577 ** order-by term to a copy of the result-set expression */ 1578 if( iCol<1 || iCol>0xffff ){ 1579 resolveOutOfRangeError(pParse, zType, i+1, nResult, pE2); 1580 return 1; 1581 } 1582 pItem->u.x.iOrderByCol = (u16)iCol; 1583 continue; 1584 } 1585 1586 /* Otherwise, treat the ORDER BY term as an ordinary expression */ 1587 pItem->u.x.iOrderByCol = 0; 1588 if( sqlite3ResolveExprNames(pNC, pE) ){ 1589 return 1; 1590 } 1591 for(j=0; j<pSelect->pEList->nExpr; j++){ 1592 if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){ 1593 /* Since this expresion is being changed into a reference 1594 ** to an identical expression in the result set, remove all Window 1595 ** objects belonging to the expression from the Select.pWin list. */ 1596 windowRemoveExprFromSelect(pSelect, pE); 1597 pItem->u.x.iOrderByCol = j+1; 1598 } 1599 } 1600 } 1601 return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType); 1602 } 1603 1604 /* 1605 ** Resolve names in the SELECT statement p and all of its descendants. 1606 */ 1607 static int resolveSelectStep(Walker *pWalker, Select *p){ 1608 NameContext *pOuterNC; /* Context that contains this SELECT */ 1609 NameContext sNC; /* Name context of this SELECT */ 1610 int isCompound; /* True if p is a compound select */ 1611 int nCompound; /* Number of compound terms processed so far */ 1612 Parse *pParse; /* Parsing context */ 1613 int i; /* Loop counter */ 1614 ExprList *pGroupBy; /* The GROUP BY clause */ 1615 Select *pLeftmost; /* Left-most of SELECT of a compound */ 1616 sqlite3 *db; /* Database connection */ 1617 1618 1619 assert( p!=0 ); 1620 if( p->selFlags & SF_Resolved ){ 1621 return WRC_Prune; 1622 } 1623 pOuterNC = pWalker->u.pNC; 1624 pParse = pWalker->pParse; 1625 db = pParse->db; 1626 1627 /* Normally sqlite3SelectExpand() will be called first and will have 1628 ** already expanded this SELECT. However, if this is a subquery within 1629 ** an expression, sqlite3ResolveExprNames() will be called without a 1630 ** prior call to sqlite3SelectExpand(). When that happens, let 1631 ** sqlite3SelectPrep() do all of the processing for this SELECT. 1632 ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and 1633 ** this routine in the correct order. 1634 */ 1635 if( (p->selFlags & SF_Expanded)==0 ){ 1636 sqlite3SelectPrep(pParse, p, pOuterNC); 1637 return pParse->nErr ? WRC_Abort : WRC_Prune; 1638 } 1639 1640 isCompound = p->pPrior!=0; 1641 nCompound = 0; 1642 pLeftmost = p; 1643 while( p ){ 1644 assert( (p->selFlags & SF_Expanded)!=0 ); 1645 assert( (p->selFlags & SF_Resolved)==0 ); 1646 assert( db->suppressErr==0 ); /* SF_Resolved not set if errors suppressed */ 1647 p->selFlags |= SF_Resolved; 1648 1649 1650 /* Resolve the expressions in the LIMIT and OFFSET clauses. These 1651 ** are not allowed to refer to any names, so pass an empty NameContext. 1652 */ 1653 memset(&sNC, 0, sizeof(sNC)); 1654 sNC.pParse = pParse; 1655 sNC.pWinSelect = p; 1656 if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){ 1657 return WRC_Abort; 1658 } 1659 1660 /* If the SF_Converted flags is set, then this Select object was 1661 ** was created by the convertCompoundSelectToSubquery() function. 1662 ** In this case the ORDER BY clause (p->pOrderBy) should be resolved 1663 ** as if it were part of the sub-query, not the parent. This block 1664 ** moves the pOrderBy down to the sub-query. It will be moved back 1665 ** after the names have been resolved. */ 1666 if( p->selFlags & SF_Converted ){ 1667 Select *pSub = p->pSrc->a[0].pSelect; 1668 assert( p->pSrc->nSrc==1 && p->pOrderBy ); 1669 assert( pSub->pPrior && pSub->pOrderBy==0 ); 1670 pSub->pOrderBy = p->pOrderBy; 1671 p->pOrderBy = 0; 1672 } 1673 1674 /* Recursively resolve names in all subqueries in the FROM clause 1675 */ 1676 for(i=0; i<p->pSrc->nSrc; i++){ 1677 SrcItem *pItem = &p->pSrc->a[i]; 1678 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){ 1679 int nRef = pOuterNC ? pOuterNC->nRef : 0; 1680 const char *zSavedContext = pParse->zAuthContext; 1681 1682 if( pItem->zName ) pParse->zAuthContext = pItem->zName; 1683 sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC); 1684 pParse->zAuthContext = zSavedContext; 1685 if( pParse->nErr ) return WRC_Abort; 1686 assert( db->mallocFailed==0 ); 1687 1688 /* If the number of references to the outer context changed when 1689 ** expressions in the sub-select were resolved, the sub-select 1690 ** is correlated. It is not required to check the refcount on any 1691 ** but the innermost outer context object, as lookupName() increments 1692 ** the refcount on all contexts between the current one and the 1693 ** context containing the column when it resolves a name. */ 1694 if( pOuterNC ){ 1695 assert( pItem->fg.isCorrelated==0 && pOuterNC->nRef>=nRef ); 1696 pItem->fg.isCorrelated = (pOuterNC->nRef>nRef); 1697 } 1698 } 1699 } 1700 1701 /* Set up the local name-context to pass to sqlite3ResolveExprNames() to 1702 ** resolve the result-set expression list. 1703 */ 1704 sNC.ncFlags = NC_AllowAgg|NC_AllowWin; 1705 sNC.pSrcList = p->pSrc; 1706 sNC.pNext = pOuterNC; 1707 1708 /* Resolve names in the result set. */ 1709 if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort; 1710 sNC.ncFlags &= ~NC_AllowWin; 1711 1712 /* If there are no aggregate functions in the result-set, and no GROUP BY 1713 ** expression, do not allow aggregates in any of the other expressions. 1714 */ 1715 assert( (p->selFlags & SF_Aggregate)==0 ); 1716 pGroupBy = p->pGroupBy; 1717 if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){ 1718 assert( NC_MinMaxAgg==SF_MinMaxAgg ); 1719 assert( NC_OrderAgg==SF_OrderByReqd ); 1720 p->selFlags |= SF_Aggregate | (sNC.ncFlags&(NC_MinMaxAgg|NC_OrderAgg)); 1721 }else{ 1722 sNC.ncFlags &= ~NC_AllowAgg; 1723 } 1724 1725 /* Add the output column list to the name-context before parsing the 1726 ** other expressions in the SELECT statement. This is so that 1727 ** expressions in the WHERE clause (etc.) can refer to expressions by 1728 ** aliases in the result set. 1729 ** 1730 ** Minor point: If this is the case, then the expression will be 1731 ** re-evaluated for each reference to it. 1732 */ 1733 assert( (sNC.ncFlags & (NC_UAggInfo|NC_UUpsert|NC_UBaseReg))==0 ); 1734 sNC.uNC.pEList = p->pEList; 1735 sNC.ncFlags |= NC_UEList; 1736 if( p->pHaving ){ 1737 if( !pGroupBy ){ 1738 sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING"); 1739 return WRC_Abort; 1740 } 1741 if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort; 1742 } 1743 if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort; 1744 1745 /* Resolve names in table-valued-function arguments */ 1746 for(i=0; i<p->pSrc->nSrc; i++){ 1747 SrcItem *pItem = &p->pSrc->a[i]; 1748 if( pItem->fg.isTabFunc 1749 && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 1750 ){ 1751 return WRC_Abort; 1752 } 1753 } 1754 1755 #ifndef SQLITE_OMIT_WINDOWFUNC 1756 if( IN_RENAME_OBJECT ){ 1757 Window *pWin; 1758 for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){ 1759 if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy) 1760 || sqlite3ResolveExprListNames(&sNC, pWin->pPartition) 1761 ){ 1762 return WRC_Abort; 1763 } 1764 } 1765 } 1766 #endif 1767 1768 /* The ORDER BY and GROUP BY clauses may not refer to terms in 1769 ** outer queries 1770 */ 1771 sNC.pNext = 0; 1772 sNC.ncFlags |= NC_AllowAgg|NC_AllowWin; 1773 1774 /* If this is a converted compound query, move the ORDER BY clause from 1775 ** the sub-query back to the parent query. At this point each term 1776 ** within the ORDER BY clause has been transformed to an integer value. 1777 ** These integers will be replaced by copies of the corresponding result 1778 ** set expressions by the call to resolveOrderGroupBy() below. */ 1779 if( p->selFlags & SF_Converted ){ 1780 Select *pSub = p->pSrc->a[0].pSelect; 1781 p->pOrderBy = pSub->pOrderBy; 1782 pSub->pOrderBy = 0; 1783 } 1784 1785 /* Process the ORDER BY clause for singleton SELECT statements. 1786 ** The ORDER BY clause for compounds SELECT statements is handled 1787 ** below, after all of the result-sets for all of the elements of 1788 ** the compound have been resolved. 1789 ** 1790 ** If there is an ORDER BY clause on a term of a compound-select other 1791 ** than the right-most term, then that is a syntax error. But the error 1792 ** is not detected until much later, and so we need to go ahead and 1793 ** resolve those symbols on the incorrect ORDER BY for consistency. 1794 */ 1795 if( p->pOrderBy!=0 1796 && isCompound<=nCompound /* Defer right-most ORDER BY of a compound */ 1797 && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") 1798 ){ 1799 return WRC_Abort; 1800 } 1801 if( db->mallocFailed ){ 1802 return WRC_Abort; 1803 } 1804 sNC.ncFlags &= ~NC_AllowWin; 1805 1806 /* Resolve the GROUP BY clause. At the same time, make sure 1807 ** the GROUP BY clause does not contain aggregate functions. 1808 */ 1809 if( pGroupBy ){ 1810 struct ExprList_item *pItem; 1811 1812 if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){ 1813 return WRC_Abort; 1814 } 1815 for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){ 1816 if( ExprHasProperty(pItem->pExpr, EP_Agg) ){ 1817 sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in " 1818 "the GROUP BY clause"); 1819 return WRC_Abort; 1820 } 1821 } 1822 } 1823 1824 /* If this is part of a compound SELECT, check that it has the right 1825 ** number of expressions in the select list. */ 1826 if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){ 1827 sqlite3SelectWrongNumTermsError(pParse, p->pNext); 1828 return WRC_Abort; 1829 } 1830 1831 /* Advance to the next term of the compound 1832 */ 1833 p = p->pPrior; 1834 nCompound++; 1835 } 1836 1837 /* Resolve the ORDER BY on a compound SELECT after all terms of 1838 ** the compound have been resolved. 1839 */ 1840 if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){ 1841 return WRC_Abort; 1842 } 1843 1844 return WRC_Prune; 1845 } 1846 1847 /* 1848 ** This routine walks an expression tree and resolves references to 1849 ** table columns and result-set columns. At the same time, do error 1850 ** checking on function usage and set a flag if any aggregate functions 1851 ** are seen. 1852 ** 1853 ** To resolve table columns references we look for nodes (or subtrees) of the 1854 ** form X.Y.Z or Y.Z or just Z where 1855 ** 1856 ** X: The name of a database. Ex: "main" or "temp" or 1857 ** the symbolic name assigned to an ATTACH-ed database. 1858 ** 1859 ** Y: The name of a table in a FROM clause. Or in a trigger 1860 ** one of the special names "old" or "new". 1861 ** 1862 ** Z: The name of a column in table Y. 1863 ** 1864 ** The node at the root of the subtree is modified as follows: 1865 ** 1866 ** Expr.op Changed to TK_COLUMN 1867 ** Expr.pTab Points to the Table object for X.Y 1868 ** Expr.iColumn The column index in X.Y. -1 for the rowid. 1869 ** Expr.iTable The VDBE cursor number for X.Y 1870 ** 1871 ** 1872 ** To resolve result-set references, look for expression nodes of the 1873 ** form Z (with no X and Y prefix) where the Z matches the right-hand 1874 ** size of an AS clause in the result-set of a SELECT. The Z expression 1875 ** is replaced by a copy of the left-hand side of the result-set expression. 1876 ** Table-name and function resolution occurs on the substituted expression 1877 ** tree. For example, in: 1878 ** 1879 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x; 1880 ** 1881 ** The "x" term of the order by is replaced by "a+b" to render: 1882 ** 1883 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b; 1884 ** 1885 ** Function calls are checked to make sure that the function is 1886 ** defined and that the correct number of arguments are specified. 1887 ** If the function is an aggregate function, then the NC_HasAgg flag is 1888 ** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION. 1889 ** If an expression contains aggregate functions then the EP_Agg 1890 ** property on the expression is set. 1891 ** 1892 ** An error message is left in pParse if anything is amiss. The number 1893 ** if errors is returned. 1894 */ 1895 int sqlite3ResolveExprNames( 1896 NameContext *pNC, /* Namespace to resolve expressions in. */ 1897 Expr *pExpr /* The expression to be analyzed. */ 1898 ){ 1899 int savedHasAgg; 1900 Walker w; 1901 1902 if( pExpr==0 ) return SQLITE_OK; 1903 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1904 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1905 w.pParse = pNC->pParse; 1906 w.xExprCallback = resolveExprStep; 1907 w.xSelectCallback = (pNC->ncFlags & NC_NoSelect) ? 0 : resolveSelectStep; 1908 w.xSelectCallback2 = 0; 1909 w.u.pNC = pNC; 1910 #if SQLITE_MAX_EXPR_DEPTH>0 1911 w.pParse->nHeight += pExpr->nHeight; 1912 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1913 return SQLITE_ERROR; 1914 } 1915 #endif 1916 sqlite3WalkExpr(&w, pExpr); 1917 #if SQLITE_MAX_EXPR_DEPTH>0 1918 w.pParse->nHeight -= pExpr->nHeight; 1919 #endif 1920 assert( EP_Agg==NC_HasAgg ); 1921 assert( EP_Win==NC_HasWin ); 1922 testcase( pNC->ncFlags & NC_HasAgg ); 1923 testcase( pNC->ncFlags & NC_HasWin ); 1924 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1925 pNC->ncFlags |= savedHasAgg; 1926 return pNC->nNcErr>0 || w.pParse->nErr>0; 1927 } 1928 1929 /* 1930 ** Resolve all names for all expression in an expression list. This is 1931 ** just like sqlite3ResolveExprNames() except that it works for an expression 1932 ** list rather than a single expression. 1933 */ 1934 int sqlite3ResolveExprListNames( 1935 NameContext *pNC, /* Namespace to resolve expressions in. */ 1936 ExprList *pList /* The expression list to be analyzed. */ 1937 ){ 1938 int i; 1939 int savedHasAgg = 0; 1940 Walker w; 1941 if( pList==0 ) return WRC_Continue; 1942 w.pParse = pNC->pParse; 1943 w.xExprCallback = resolveExprStep; 1944 w.xSelectCallback = resolveSelectStep; 1945 w.xSelectCallback2 = 0; 1946 w.u.pNC = pNC; 1947 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1948 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1949 for(i=0; i<pList->nExpr; i++){ 1950 Expr *pExpr = pList->a[i].pExpr; 1951 if( pExpr==0 ) continue; 1952 #if SQLITE_MAX_EXPR_DEPTH>0 1953 w.pParse->nHeight += pExpr->nHeight; 1954 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1955 return WRC_Abort; 1956 } 1957 #endif 1958 sqlite3WalkExpr(&w, pExpr); 1959 #if SQLITE_MAX_EXPR_DEPTH>0 1960 w.pParse->nHeight -= pExpr->nHeight; 1961 #endif 1962 assert( EP_Agg==NC_HasAgg ); 1963 assert( EP_Win==NC_HasWin ); 1964 testcase( pNC->ncFlags & NC_HasAgg ); 1965 testcase( pNC->ncFlags & NC_HasWin ); 1966 if( pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg) ){ 1967 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1968 savedHasAgg |= pNC->ncFlags & 1969 (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1970 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1971 } 1972 if( w.pParse->nErr>0 ) return WRC_Abort; 1973 } 1974 pNC->ncFlags |= savedHasAgg; 1975 return WRC_Continue; 1976 } 1977 1978 /* 1979 ** Resolve all names in all expressions of a SELECT and in all 1980 ** decendents of the SELECT, including compounds off of p->pPrior, 1981 ** subqueries in expressions, and subqueries used as FROM clause 1982 ** terms. 1983 ** 1984 ** See sqlite3ResolveExprNames() for a description of the kinds of 1985 ** transformations that occur. 1986 ** 1987 ** All SELECT statements should have been expanded using 1988 ** sqlite3SelectExpand() prior to invoking this routine. 1989 */ 1990 void sqlite3ResolveSelectNames( 1991 Parse *pParse, /* The parser context */ 1992 Select *p, /* The SELECT statement being coded. */ 1993 NameContext *pOuterNC /* Name context for parent SELECT statement */ 1994 ){ 1995 Walker w; 1996 1997 assert( p!=0 ); 1998 w.xExprCallback = resolveExprStep; 1999 w.xSelectCallback = resolveSelectStep; 2000 w.xSelectCallback2 = 0; 2001 w.pParse = pParse; 2002 w.u.pNC = pOuterNC; 2003 sqlite3WalkSelect(&w, p); 2004 } 2005 2006 /* 2007 ** Resolve names in expressions that can only reference a single table 2008 ** or which cannot reference any tables at all. Examples: 2009 ** 2010 ** "type" flag 2011 ** ------------ 2012 ** (1) CHECK constraints NC_IsCheck 2013 ** (2) WHERE clauses on partial indices NC_PartIdx 2014 ** (3) Expressions in indexes on expressions NC_IdxExpr 2015 ** (4) Expression arguments to VACUUM INTO. 0 2016 ** (5) GENERATED ALWAYS as expressions NC_GenCol 2017 ** 2018 ** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN 2019 ** nodes of the expression is set to -1 and the Expr.iColumn value is 2020 ** set to the column number. In case (4), TK_COLUMN nodes cause an error. 2021 ** 2022 ** Any errors cause an error message to be set in pParse. 2023 */ 2024 int sqlite3ResolveSelfReference( 2025 Parse *pParse, /* Parsing context */ 2026 Table *pTab, /* The table being referenced, or NULL */ 2027 int type, /* NC_IsCheck, NC_PartIdx, NC_IdxExpr, NC_GenCol, or 0 */ 2028 Expr *pExpr, /* Expression to resolve. May be NULL. */ 2029 ExprList *pList /* Expression list to resolve. May be NULL. */ 2030 ){ 2031 SrcList sSrc; /* Fake SrcList for pParse->pNewTable */ 2032 NameContext sNC; /* Name context for pParse->pNewTable */ 2033 int rc; 2034 2035 assert( type==0 || pTab!=0 ); 2036 assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr 2037 || type==NC_GenCol || pTab==0 ); 2038 memset(&sNC, 0, sizeof(sNC)); 2039 memset(&sSrc, 0, sizeof(sSrc)); 2040 if( pTab ){ 2041 sSrc.nSrc = 1; 2042 sSrc.a[0].zName = pTab->zName; 2043 sSrc.a[0].pTab = pTab; 2044 sSrc.a[0].iCursor = -1; 2045 if( pTab->pSchema!=pParse->db->aDb[1].pSchema ){ 2046 /* Cause EP_FromDDL to be set on TK_FUNCTION nodes of non-TEMP 2047 ** schema elements */ 2048 type |= NC_FromDDL; 2049 } 2050 } 2051 sNC.pParse = pParse; 2052 sNC.pSrcList = &sSrc; 2053 sNC.ncFlags = type | NC_IsDDL; 2054 if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc; 2055 if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList); 2056 return rc; 2057 } 2058