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 && pTab->pSchema!=pSchema ){ 324 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( nameInUsingClause(pItem->pUsing, zCol) ) continue; 349 } 350 cnt++; 351 pMatch = pItem; 352 /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ 353 pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j; 354 break; 355 } 356 } 357 if( 0==cnt && VisibleRowid(pTab) ){ 358 cntTab++; 359 pMatch = pItem; 360 } 361 } 362 if( pMatch ){ 363 pExpr->iTable = pMatch->iCursor; 364 assert( ExprUseYTab(pExpr) ); 365 pExpr->y.pTab = pMatch->pTab; 366 /* RIGHT JOIN not (yet) supported */ 367 assert( (pMatch->fg.jointype & JT_RIGHT)==0 ); 368 if( (pMatch->fg.jointype & JT_LEFT)!=0 ){ 369 ExprSetProperty(pExpr, EP_CanBeNull); 370 } 371 pSchema = pExpr->y.pTab->pSchema; 372 } 373 } /* if( pSrcList ) */ 374 375 #if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) 376 /* If we have not already resolved the name, then maybe 377 ** it is a new.* or old.* trigger argument reference. Or 378 ** maybe it is an excluded.* from an upsert. Or maybe it is 379 ** a reference in the RETURNING clause to a table being modified. 380 */ 381 if( cnt==0 && zDb==0 ){ 382 pTab = 0; 383 #ifndef SQLITE_OMIT_TRIGGER 384 if( pParse->pTriggerTab!=0 ){ 385 int op = pParse->eTriggerOp; 386 assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT ); 387 if( pParse->bReturning ){ 388 if( (pNC->ncFlags & NC_UBaseReg)!=0 389 && (zTab==0 || sqlite3StrICmp(zTab,pParse->pTriggerTab->zName)==0) 390 ){ 391 pExpr->iTable = op!=TK_DELETE; 392 pTab = pParse->pTriggerTab; 393 } 394 }else if( op!=TK_DELETE && zTab && sqlite3StrICmp("new",zTab) == 0 ){ 395 pExpr->iTable = 1; 396 pTab = pParse->pTriggerTab; 397 }else if( op!=TK_INSERT && zTab && sqlite3StrICmp("old",zTab)==0 ){ 398 pExpr->iTable = 0; 399 pTab = pParse->pTriggerTab; 400 } 401 } 402 #endif /* SQLITE_OMIT_TRIGGER */ 403 #ifndef SQLITE_OMIT_UPSERT 404 if( (pNC->ncFlags & NC_UUpsert)!=0 && zTab!=0 ){ 405 Upsert *pUpsert = pNC->uNC.pUpsert; 406 if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){ 407 pTab = pUpsert->pUpsertSrc->a[0].pTab; 408 pExpr->iTable = EXCLUDED_TABLE_NUMBER; 409 } 410 } 411 #endif /* SQLITE_OMIT_UPSERT */ 412 413 if( pTab ){ 414 int iCol; 415 u8 hCol = sqlite3StrIHash(zCol); 416 pSchema = pTab->pSchema; 417 cntTab++; 418 for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){ 419 if( pCol->hName==hCol 420 && sqlite3StrICmp(pCol->zCnName, zCol)==0 421 ){ 422 if( iCol==pTab->iPKey ){ 423 iCol = -1; 424 } 425 break; 426 } 427 } 428 if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){ 429 /* IMP: R-51414-32910 */ 430 iCol = -1; 431 } 432 if( iCol<pTab->nCol ){ 433 cnt++; 434 pMatch = 0; 435 #ifndef SQLITE_OMIT_UPSERT 436 if( pExpr->iTable==EXCLUDED_TABLE_NUMBER ){ 437 testcase( iCol==(-1) ); 438 assert( ExprUseYTab(pExpr) ); 439 if( IN_RENAME_OBJECT ){ 440 pExpr->iColumn = iCol; 441 pExpr->y.pTab = pTab; 442 eNewExprOp = TK_COLUMN; 443 }else{ 444 pExpr->iTable = pNC->uNC.pUpsert->regData + 445 sqlite3TableColumnToStorage(pTab, iCol); 446 eNewExprOp = TK_REGISTER; 447 } 448 }else 449 #endif /* SQLITE_OMIT_UPSERT */ 450 { 451 assert( ExprUseYTab(pExpr) ); 452 pExpr->y.pTab = pTab; 453 if( pParse->bReturning ){ 454 eNewExprOp = TK_REGISTER; 455 pExpr->iTable = pNC->uNC.iBaseReg + (pTab->nCol+1)*pExpr->iTable + 456 sqlite3TableColumnToStorage(pTab, iCol) + 1; 457 }else{ 458 pExpr->iColumn = (i16)iCol; 459 eNewExprOp = TK_TRIGGER; 460 #ifndef SQLITE_OMIT_TRIGGER 461 if( iCol<0 ){ 462 pExpr->affExpr = SQLITE_AFF_INTEGER; 463 }else if( pExpr->iTable==0 ){ 464 testcase( iCol==31 ); 465 testcase( iCol==32 ); 466 pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 467 }else{ 468 testcase( iCol==31 ); 469 testcase( iCol==32 ); 470 pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 471 } 472 #endif /* SQLITE_OMIT_TRIGGER */ 473 } 474 } 475 } 476 } 477 } 478 #endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */ 479 480 /* 481 ** Perhaps the name is a reference to the ROWID 482 */ 483 if( cnt==0 484 && cntTab==1 485 && pMatch 486 && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0 487 && sqlite3IsRowid(zCol) 488 && ALWAYS(VisibleRowid(pMatch->pTab)) 489 ){ 490 cnt = 1; 491 pExpr->iColumn = -1; 492 pExpr->affExpr = SQLITE_AFF_INTEGER; 493 } 494 495 /* 496 ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z 497 ** might refer to an result-set alias. This happens, for example, when 498 ** we are resolving names in the WHERE clause of the following command: 499 ** 500 ** SELECT a+b AS x FROM table WHERE x<10; 501 ** 502 ** In cases like this, replace pExpr with a copy of the expression that 503 ** forms the result set entry ("a+b" in the example) and return immediately. 504 ** Note that the expression in the result set should have already been 505 ** resolved by the time the WHERE clause is resolved. 506 ** 507 ** The ability to use an output result-set column in the WHERE, GROUP BY, 508 ** or HAVING clauses, or as part of a larger expression in the ORDER BY 509 ** clause is not standard SQL. This is a (goofy) SQLite extension, that 510 ** is supported for backwards compatibility only. Hence, we issue a warning 511 ** on sqlite3_log() whenever the capability is used. 512 */ 513 if( cnt==0 514 && (pNC->ncFlags & NC_UEList)!=0 515 && zTab==0 516 ){ 517 pEList = pNC->uNC.pEList; 518 assert( pEList!=0 ); 519 for(j=0; j<pEList->nExpr; j++){ 520 char *zAs = pEList->a[j].zEName; 521 if( pEList->a[j].eEName==ENAME_NAME 522 && sqlite3_stricmp(zAs, zCol)==0 523 ){ 524 Expr *pOrig; 525 assert( pExpr->pLeft==0 && pExpr->pRight==0 ); 526 assert( ExprUseXList(pExpr)==0 || pExpr->x.pList==0 ); 527 assert( ExprUseXSelect(pExpr)==0 || pExpr->x.pSelect==0 ); 528 pOrig = pEList->a[j].pExpr; 529 if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){ 530 sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs); 531 return WRC_Abort; 532 } 533 if( ExprHasProperty(pOrig, EP_Win) 534 && ((pNC->ncFlags&NC_AllowWin)==0 || pNC!=pTopNC ) 535 ){ 536 sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs); 537 return WRC_Abort; 538 } 539 if( sqlite3ExprVectorSize(pOrig)!=1 ){ 540 sqlite3ErrorMsg(pParse, "row value misused"); 541 return WRC_Abort; 542 } 543 resolveAlias(pParse, pEList, j, pExpr, nSubquery); 544 cnt = 1; 545 pMatch = 0; 546 assert( zTab==0 && zDb==0 ); 547 if( IN_RENAME_OBJECT ){ 548 sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr); 549 } 550 goto lookupname_end; 551 } 552 } 553 } 554 555 /* Advance to the next name context. The loop will exit when either 556 ** we have a match (cnt>0) or when we run out of name contexts. 557 */ 558 if( cnt ) break; 559 pNC = pNC->pNext; 560 nSubquery++; 561 }while( pNC ); 562 563 564 /* 565 ** If X and Y are NULL (in other words if only the column name Z is 566 ** supplied) and the value of Z is enclosed in double-quotes, then 567 ** Z is a string literal if it doesn't match any column names. In that 568 ** case, we need to return right away and not make any changes to 569 ** pExpr. 570 ** 571 ** Because no reference was made to outer contexts, the pNC->nRef 572 ** fields are not changed in any context. 573 */ 574 if( cnt==0 && zTab==0 ){ 575 assert( pExpr->op==TK_ID ); 576 if( ExprHasProperty(pExpr,EP_DblQuoted) 577 && areDoubleQuotedStringsEnabled(db, pTopNC) 578 ){ 579 /* If a double-quoted identifier does not match any known column name, 580 ** then treat it as a string. 581 ** 582 ** This hack was added in the early days of SQLite in a misguided attempt 583 ** to be compatible with MySQL 3.x, which used double-quotes for strings. 584 ** I now sorely regret putting in this hack. The effect of this hack is 585 ** that misspelled identifier names are silently converted into strings 586 ** rather than causing an error, to the frustration of countless 587 ** programmers. To all those frustrated programmers, my apologies. 588 ** 589 ** Someday, I hope to get rid of this hack. Unfortunately there is 590 ** a huge amount of legacy SQL that uses it. So for now, we just 591 ** issue a warning. 592 */ 593 sqlite3_log(SQLITE_WARNING, 594 "double-quoted string literal: \"%w\"", zCol); 595 #ifdef SQLITE_ENABLE_NORMALIZE 596 sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol); 597 #endif 598 pExpr->op = TK_STRING; 599 memset(&pExpr->y, 0, sizeof(pExpr->y)); 600 return WRC_Prune; 601 } 602 if( sqlite3ExprIdToTrueFalse(pExpr) ){ 603 return WRC_Prune; 604 } 605 } 606 607 /* 608 ** cnt==0 means there was not match. cnt>1 means there were two or 609 ** more matches. Either way, we have an error. 610 */ 611 if( cnt!=1 ){ 612 const char *zErr; 613 zErr = cnt==0 ? "no such column" : "ambiguous column name"; 614 if( zDb ){ 615 sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol); 616 }else if( zTab ){ 617 sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol); 618 }else{ 619 sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol); 620 } 621 pParse->checkSchema = 1; 622 pTopNC->nNcErr++; 623 } 624 625 /* If a column from a table in pSrcList is referenced, then record 626 ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes 627 ** bit 0 to be set. Column 1 sets bit 1. And so forth. Bit 63 is 628 ** set if the 63rd or any subsequent column is used. 629 ** 630 ** The colUsed mask is an optimization used to help determine if an 631 ** index is a covering index. The correct answer is still obtained 632 ** if the mask contains extra set bits. However, it is important to 633 ** avoid setting bits beyond the maximum column number of the table. 634 ** (See ticket [b92e5e8ec2cdbaa1]). 635 ** 636 ** If a generated column is referenced, set bits for every column 637 ** of the table. 638 */ 639 if( pExpr->iColumn>=0 && pMatch!=0 ){ 640 pMatch->colUsed |= sqlite3ExprColUsed(pExpr); 641 } 642 643 /* Clean up and return 644 */ 645 if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){ 646 sqlite3ExprDelete(db, pExpr->pLeft); 647 pExpr->pLeft = 0; 648 sqlite3ExprDelete(db, pExpr->pRight); 649 pExpr->pRight = 0; 650 } 651 pExpr->op = eNewExprOp; 652 ExprSetProperty(pExpr, EP_Leaf); 653 lookupname_end: 654 if( cnt==1 ){ 655 assert( pNC!=0 ); 656 #ifndef SQLITE_OMIT_AUTHORIZATION 657 if( pParse->db->xAuth 658 && (pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER) 659 ){ 660 sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); 661 } 662 #endif 663 /* Increment the nRef value on all name contexts from TopNC up to 664 ** the point where the name matched. */ 665 for(;;){ 666 assert( pTopNC!=0 ); 667 pTopNC->nRef++; 668 if( pTopNC==pNC ) break; 669 pTopNC = pTopNC->pNext; 670 } 671 return WRC_Prune; 672 } else { 673 return WRC_Abort; 674 } 675 } 676 677 /* 678 ** Allocate and return a pointer to an expression to load the column iCol 679 ** from datasource iSrc in SrcList pSrc. 680 */ 681 Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){ 682 Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0); 683 if( p ){ 684 SrcItem *pItem = &pSrc->a[iSrc]; 685 Table *pTab; 686 assert( ExprUseYTab(p) ); 687 pTab = p->y.pTab = pItem->pTab; 688 p->iTable = pItem->iCursor; 689 if( p->y.pTab->iPKey==iCol ){ 690 p->iColumn = -1; 691 }else{ 692 p->iColumn = (ynVar)iCol; 693 if( (pTab->tabFlags & TF_HasGenerated)!=0 694 && (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0 695 ){ 696 testcase( pTab->nCol==63 ); 697 testcase( pTab->nCol==64 ); 698 pItem->colUsed = pTab->nCol>=64 ? ALLBITS : MASKBIT(pTab->nCol)-1; 699 }else{ 700 testcase( iCol==BMS ); 701 testcase( iCol==BMS-1 ); 702 pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol); 703 } 704 } 705 } 706 return p; 707 } 708 709 /* 710 ** Report an error that an expression is not valid for some set of 711 ** pNC->ncFlags values determined by validMask. 712 ** 713 ** static void notValid( 714 ** Parse *pParse, // Leave error message here 715 ** NameContext *pNC, // The name context 716 ** const char *zMsg, // Type of error 717 ** int validMask, // Set of contexts for which prohibited 718 ** Expr *pExpr // Invalidate this expression on error 719 ** ){...} 720 ** 721 ** As an optimization, since the conditional is almost always false 722 ** (because errors are rare), the conditional is moved outside of the 723 ** function call using a macro. 724 */ 725 static void notValidImpl( 726 Parse *pParse, /* Leave error message here */ 727 NameContext *pNC, /* The name context */ 728 const char *zMsg, /* Type of error */ 729 Expr *pExpr /* Invalidate this expression on error */ 730 ){ 731 const char *zIn = "partial index WHERE clauses"; 732 if( pNC->ncFlags & NC_IdxExpr ) zIn = "index expressions"; 733 #ifndef SQLITE_OMIT_CHECK 734 else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints"; 735 #endif 736 #ifndef SQLITE_OMIT_GENERATED_COLUMNS 737 else if( pNC->ncFlags & NC_GenCol ) zIn = "generated columns"; 738 #endif 739 sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn); 740 if( pExpr ) pExpr->op = TK_NULL; 741 } 742 #define sqlite3ResolveNotValid(P,N,M,X,E) \ 743 assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \ 744 if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E); 745 746 /* 747 ** Expression p should encode a floating point value between 1.0 and 0.0. 748 ** Return 1024 times this value. Or return -1 if p is not a floating point 749 ** value between 1.0 and 0.0. 750 */ 751 static int exprProbability(Expr *p){ 752 double r = -1.0; 753 if( p->op!=TK_FLOAT ) return -1; 754 assert( !ExprHasProperty(p, EP_IntValue) ); 755 sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8); 756 assert( r>=0.0 ); 757 if( r>1.0 ) return -1; 758 return (int)(r*134217728.0); 759 } 760 761 /* 762 ** This routine is callback for sqlite3WalkExpr(). 763 ** 764 ** Resolve symbolic names into TK_COLUMN operators for the current 765 ** node in the expression tree. Return 0 to continue the search down 766 ** the tree or 2 to abort the tree walk. 767 ** 768 ** This routine also does error checking and name resolution for 769 ** function names. The operator for aggregate functions is changed 770 ** to TK_AGG_FUNCTION. 771 */ 772 static int resolveExprStep(Walker *pWalker, Expr *pExpr){ 773 NameContext *pNC; 774 Parse *pParse; 775 776 pNC = pWalker->u.pNC; 777 assert( pNC!=0 ); 778 pParse = pNC->pParse; 779 assert( pParse==pWalker->pParse ); 780 781 #ifndef NDEBUG 782 if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ 783 SrcList *pSrcList = pNC->pSrcList; 784 int i; 785 for(i=0; i<pNC->pSrcList->nSrc; i++){ 786 assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); 787 } 788 } 789 #endif 790 switch( pExpr->op ){ 791 792 /* The special operator TK_ROW means use the rowid for the first 793 ** column in the FROM clause. This is used by the LIMIT and ORDER BY 794 ** clause processing on UPDATE and DELETE statements, and by 795 ** UPDATE ... FROM statement processing. 796 */ 797 case TK_ROW: { 798 SrcList *pSrcList = pNC->pSrcList; 799 SrcItem *pItem; 800 assert( pSrcList && pSrcList->nSrc>=1 ); 801 pItem = pSrcList->a; 802 pExpr->op = TK_COLUMN; 803 assert( ExprUseYTab(pExpr) ); 804 pExpr->y.pTab = pItem->pTab; 805 pExpr->iTable = pItem->iCursor; 806 pExpr->iColumn--; 807 pExpr->affExpr = SQLITE_AFF_INTEGER; 808 break; 809 } 810 811 /* An optimization: Attempt to convert 812 ** 813 ** "expr IS NOT NULL" --> "TRUE" 814 ** "expr IS NULL" --> "FALSE" 815 ** 816 ** if we can prove that "expr" is never NULL. Call this the 817 ** "NOT NULL strength reduction optimization". 818 ** 819 ** If this optimization occurs, also restore the NameContext ref-counts 820 ** to the state they where in before the "column" LHS expression was 821 ** resolved. This prevents "column" from being counted as having been 822 ** referenced, which might prevent a SELECT from being erroneously 823 ** marked as correlated. 824 */ 825 case TK_NOTNULL: 826 case TK_ISNULL: { 827 int anRef[8]; 828 NameContext *p; 829 int i; 830 for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ 831 anRef[i] = p->nRef; 832 } 833 sqlite3WalkExpr(pWalker, pExpr->pLeft); 834 if( 0==sqlite3ExprCanBeNull(pExpr->pLeft) && !IN_RENAME_OBJECT ){ 835 testcase( ExprHasProperty(pExpr, EP_FromJoin) ); 836 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 837 if( pExpr->op==TK_NOTNULL ){ 838 pExpr->u.zToken = "true"; 839 ExprSetProperty(pExpr, EP_IsTrue); 840 }else{ 841 pExpr->u.zToken = "false"; 842 ExprSetProperty(pExpr, EP_IsFalse); 843 } 844 pExpr->op = TK_TRUEFALSE; 845 for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ 846 p->nRef = anRef[i]; 847 } 848 sqlite3ExprDelete(pParse->db, pExpr->pLeft); 849 pExpr->pLeft = 0; 850 } 851 return WRC_Prune; 852 } 853 854 /* A column name: ID 855 ** Or table name and column name: ID.ID 856 ** Or a database, table and column: ID.ID.ID 857 ** 858 ** The TK_ID and TK_OUT cases are combined so that there will only 859 ** be one call to lookupName(). Then the compiler will in-line 860 ** lookupName() for a size reduction and performance increase. 861 */ 862 case TK_ID: 863 case TK_DOT: { 864 const char *zColumn; 865 const char *zTable; 866 const char *zDb; 867 Expr *pRight; 868 869 if( pExpr->op==TK_ID ){ 870 zDb = 0; 871 zTable = 0; 872 assert( !ExprHasProperty(pExpr, EP_IntValue) ); 873 zColumn = pExpr->u.zToken; 874 }else{ 875 Expr *pLeft = pExpr->pLeft; 876 testcase( pNC->ncFlags & NC_IdxExpr ); 877 testcase( pNC->ncFlags & NC_GenCol ); 878 sqlite3ResolveNotValid(pParse, pNC, "the \".\" operator", 879 NC_IdxExpr|NC_GenCol, 0); 880 pRight = pExpr->pRight; 881 if( pRight->op==TK_ID ){ 882 zDb = 0; 883 }else{ 884 assert( pRight->op==TK_DOT ); 885 assert( !ExprHasProperty(pRight, EP_IntValue) ); 886 zDb = pLeft->u.zToken; 887 pLeft = pRight->pLeft; 888 pRight = pRight->pRight; 889 } 890 assert( ExprUseUToken(pLeft) && ExprUseUToken(pRight) ); 891 zTable = pLeft->u.zToken; 892 zColumn = pRight->u.zToken; 893 assert( ExprUseYTab(pExpr) ); 894 if( IN_RENAME_OBJECT ){ 895 sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight); 896 sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft); 897 } 898 } 899 return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr); 900 } 901 902 /* Resolve function names 903 */ 904 case TK_FUNCTION: { 905 ExprList *pList = pExpr->x.pList; /* The argument list */ 906 int n = pList ? pList->nExpr : 0; /* Number of arguments */ 907 int no_such_func = 0; /* True if no such function exists */ 908 int wrong_num_args = 0; /* True if wrong number of arguments */ 909 int is_agg = 0; /* True if is an aggregate function */ 910 int nId; /* Number of characters in function name */ 911 const char *zId; /* The function name. */ 912 FuncDef *pDef; /* Information about the function */ 913 u8 enc = ENC(pParse->db); /* The database encoding */ 914 int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin)); 915 #ifndef SQLITE_OMIT_WINDOWFUNC 916 Window *pWin = (IsWindowFunc(pExpr) ? pExpr->y.pWin : 0); 917 #endif 918 assert( !ExprHasProperty(pExpr, EP_xIsSelect|EP_IntValue) ); 919 zId = pExpr->u.zToken; 920 nId = sqlite3Strlen30(zId); 921 pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0); 922 if( pDef==0 ){ 923 pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0); 924 if( pDef==0 ){ 925 no_such_func = 1; 926 }else{ 927 wrong_num_args = 1; 928 } 929 }else{ 930 is_agg = pDef->xFinalize!=0; 931 if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){ 932 ExprSetProperty(pExpr, EP_Unlikely); 933 if( n==2 ){ 934 pExpr->iTable = exprProbability(pList->a[1].pExpr); 935 if( pExpr->iTable<0 ){ 936 sqlite3ErrorMsg(pParse, 937 "second argument to likelihood() must be a " 938 "constant between 0.0 and 1.0"); 939 pNC->nNcErr++; 940 } 941 }else{ 942 /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is 943 ** equivalent to likelihood(X, 0.0625). 944 ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is 945 ** short-hand for likelihood(X,0.0625). 946 ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand 947 ** for likelihood(X,0.9375). 948 ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent 949 ** to likelihood(X,0.9375). */ 950 /* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */ 951 pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120; 952 } 953 } 954 #ifndef SQLITE_OMIT_AUTHORIZATION 955 { 956 int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0); 957 if( auth!=SQLITE_OK ){ 958 if( auth==SQLITE_DENY ){ 959 sqlite3ErrorMsg(pParse, "not authorized to use function: %s", 960 pDef->zName); 961 pNC->nNcErr++; 962 } 963 pExpr->op = TK_NULL; 964 return WRC_Prune; 965 } 966 } 967 #endif 968 if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){ 969 /* For the purposes of the EP_ConstFunc flag, date and time 970 ** functions and other functions that change slowly are considered 971 ** constant because they are constant for the duration of one query. 972 ** This allows them to be factored out of inner loops. */ 973 ExprSetProperty(pExpr,EP_ConstFunc); 974 } 975 if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){ 976 /* Clearly non-deterministic functions like random(), but also 977 ** date/time functions that use 'now', and other functions like 978 ** sqlite_version() that might change over time cannot be used 979 ** in an index or generated column. Curiously, they can be used 980 ** in a CHECK constraint. SQLServer, MySQL, and PostgreSQL all 981 ** all this. */ 982 sqlite3ResolveNotValid(pParse, pNC, "non-deterministic functions", 983 NC_IdxExpr|NC_PartIdx|NC_GenCol, 0); 984 }else{ 985 assert( (NC_SelfRef & 0xff)==NC_SelfRef ); /* Must fit in 8 bits */ 986 pExpr->op2 = pNC->ncFlags & NC_SelfRef; 987 if( pNC->ncFlags & NC_FromDDL ) ExprSetProperty(pExpr, EP_FromDDL); 988 } 989 if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0 990 && pParse->nested==0 991 && (pParse->db->mDbFlags & DBFLAG_InternalFunc)==0 992 ){ 993 /* Internal-use-only functions are disallowed unless the 994 ** SQL is being compiled using sqlite3NestedParse() or 995 ** the SQLITE_TESTCTRL_INTERNAL_FUNCTIONS test-control has be 996 ** used to activate internal functionsn for testing purposes */ 997 no_such_func = 1; 998 pDef = 0; 999 }else 1000 if( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 1001 && !IN_RENAME_OBJECT 1002 ){ 1003 sqlite3ExprFunctionUsable(pParse, pExpr, pDef); 1004 } 1005 } 1006 1007 if( 0==IN_RENAME_OBJECT ){ 1008 #ifndef SQLITE_OMIT_WINDOWFUNC 1009 assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX) 1010 || (pDef->xValue==0 && pDef->xInverse==0) 1011 || (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize) 1012 ); 1013 if( pDef && pDef->xValue==0 && pWin ){ 1014 sqlite3ErrorMsg(pParse, 1015 "%.*s() may not be used as a window function", nId, zId 1016 ); 1017 pNC->nNcErr++; 1018 }else if( 1019 (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) 1020 || (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pWin) 1021 || (is_agg && pWin && (pNC->ncFlags & NC_AllowWin)==0) 1022 ){ 1023 const char *zType; 1024 if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pWin ){ 1025 zType = "window"; 1026 }else{ 1027 zType = "aggregate"; 1028 } 1029 sqlite3ErrorMsg(pParse, "misuse of %s function %.*s()",zType,nId,zId); 1030 pNC->nNcErr++; 1031 is_agg = 0; 1032 } 1033 #else 1034 if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){ 1035 sqlite3ErrorMsg(pParse,"misuse of aggregate function %.*s()",nId,zId); 1036 pNC->nNcErr++; 1037 is_agg = 0; 1038 } 1039 #endif 1040 else if( no_such_func && pParse->db->init.busy==0 1041 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION 1042 && pParse->explain==0 1043 #endif 1044 ){ 1045 sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); 1046 pNC->nNcErr++; 1047 }else if( wrong_num_args ){ 1048 sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", 1049 nId, zId); 1050 pNC->nNcErr++; 1051 } 1052 #ifndef SQLITE_OMIT_WINDOWFUNC 1053 else if( is_agg==0 && ExprHasProperty(pExpr, EP_WinFunc) ){ 1054 sqlite3ErrorMsg(pParse, 1055 "FILTER may not be used with non-aggregate %.*s()", 1056 nId, zId 1057 ); 1058 pNC->nNcErr++; 1059 } 1060 #endif 1061 if( is_agg ){ 1062 /* Window functions may not be arguments of aggregate functions. 1063 ** Or arguments of other window functions. But aggregate functions 1064 ** may be arguments for window functions. */ 1065 #ifndef SQLITE_OMIT_WINDOWFUNC 1066 pNC->ncFlags &= ~(NC_AllowWin | (!pWin ? NC_AllowAgg : 0)); 1067 #else 1068 pNC->ncFlags &= ~NC_AllowAgg; 1069 #endif 1070 } 1071 } 1072 #ifndef SQLITE_OMIT_WINDOWFUNC 1073 else if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1074 is_agg = 1; 1075 } 1076 #endif 1077 sqlite3WalkExprList(pWalker, pList); 1078 if( is_agg ){ 1079 #ifndef SQLITE_OMIT_WINDOWFUNC 1080 if( pWin ){ 1081 Select *pSel = pNC->pWinSelect; 1082 assert( pWin==0 || (ExprUseYWin(pExpr) && pWin==pExpr->y.pWin) ); 1083 if( IN_RENAME_OBJECT==0 ){ 1084 sqlite3WindowUpdate(pParse, pSel ? pSel->pWinDefn : 0, pWin, pDef); 1085 if( pParse->db->mallocFailed ) break; 1086 } 1087 sqlite3WalkExprList(pWalker, pWin->pPartition); 1088 sqlite3WalkExprList(pWalker, pWin->pOrderBy); 1089 sqlite3WalkExpr(pWalker, pWin->pFilter); 1090 sqlite3WindowLink(pSel, pWin); 1091 pNC->ncFlags |= NC_HasWin; 1092 }else 1093 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1094 { 1095 NameContext *pNC2 = pNC; 1096 pExpr->op = TK_AGG_FUNCTION; 1097 pExpr->op2 = 0; 1098 #ifndef SQLITE_OMIT_WINDOWFUNC 1099 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1100 sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter); 1101 } 1102 #endif 1103 while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){ 1104 pExpr->op2++; 1105 pNC2 = pNC2->pNext; 1106 } 1107 assert( pDef!=0 || IN_RENAME_OBJECT ); 1108 if( pNC2 && pDef ){ 1109 assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg ); 1110 assert( SQLITE_FUNC_ANYORDER==NC_OrderAgg ); 1111 testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 ); 1112 testcase( (pDef->funcFlags & SQLITE_FUNC_ANYORDER)!=0 ); 1113 pNC2->ncFlags |= NC_HasAgg 1114 | ((pDef->funcFlags^SQLITE_FUNC_ANYORDER) 1115 & (SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER)); 1116 } 1117 } 1118 pNC->ncFlags |= savedAllowFlags; 1119 } 1120 /* FIX ME: Compute pExpr->affinity based on the expected return 1121 ** type of the function 1122 */ 1123 return WRC_Prune; 1124 } 1125 #ifndef SQLITE_OMIT_SUBQUERY 1126 case TK_SELECT: 1127 case TK_EXISTS: testcase( pExpr->op==TK_EXISTS ); 1128 #endif 1129 case TK_IN: { 1130 testcase( pExpr->op==TK_IN ); 1131 if( ExprUseXSelect(pExpr) ){ 1132 int nRef = pNC->nRef; 1133 testcase( pNC->ncFlags & NC_IsCheck ); 1134 testcase( pNC->ncFlags & NC_PartIdx ); 1135 testcase( pNC->ncFlags & NC_IdxExpr ); 1136 testcase( pNC->ncFlags & NC_GenCol ); 1137 if( pNC->ncFlags & NC_SelfRef ){ 1138 notValidImpl(pParse, pNC, "subqueries", pExpr); 1139 }else{ 1140 sqlite3WalkSelect(pWalker, pExpr->x.pSelect); 1141 } 1142 assert( pNC->nRef>=nRef ); 1143 if( nRef!=pNC->nRef ){ 1144 ExprSetProperty(pExpr, EP_VarSelect); 1145 pNC->ncFlags |= NC_VarSelect; 1146 } 1147 } 1148 break; 1149 } 1150 case TK_VARIABLE: { 1151 testcase( pNC->ncFlags & NC_IsCheck ); 1152 testcase( pNC->ncFlags & NC_PartIdx ); 1153 testcase( pNC->ncFlags & NC_IdxExpr ); 1154 testcase( pNC->ncFlags & NC_GenCol ); 1155 sqlite3ResolveNotValid(pParse, pNC, "parameters", 1156 NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol, pExpr); 1157 break; 1158 } 1159 case TK_IS: 1160 case TK_ISNOT: { 1161 Expr *pRight = sqlite3ExprSkipCollateAndLikely(pExpr->pRight); 1162 assert( !ExprHasProperty(pExpr, EP_Reduced) ); 1163 /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE", 1164 ** and "x IS NOT FALSE". */ 1165 if( ALWAYS(pRight) && (pRight->op==TK_ID || pRight->op==TK_TRUEFALSE) ){ 1166 int rc = resolveExprStep(pWalker, pRight); 1167 if( rc==WRC_Abort ) return WRC_Abort; 1168 if( pRight->op==TK_TRUEFALSE ){ 1169 pExpr->op2 = pExpr->op; 1170 pExpr->op = TK_TRUTH; 1171 return WRC_Continue; 1172 } 1173 } 1174 /* no break */ deliberate_fall_through 1175 } 1176 case TK_BETWEEN: 1177 case TK_EQ: 1178 case TK_NE: 1179 case TK_LT: 1180 case TK_LE: 1181 case TK_GT: 1182 case TK_GE: { 1183 int nLeft, nRight; 1184 if( pParse->db->mallocFailed ) break; 1185 assert( pExpr->pLeft!=0 ); 1186 nLeft = sqlite3ExprVectorSize(pExpr->pLeft); 1187 if( pExpr->op==TK_BETWEEN ){ 1188 assert( ExprUseXList(pExpr) ); 1189 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr); 1190 if( nRight==nLeft ){ 1191 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr); 1192 } 1193 }else{ 1194 assert( pExpr->pRight!=0 ); 1195 nRight = sqlite3ExprVectorSize(pExpr->pRight); 1196 } 1197 if( nLeft!=nRight ){ 1198 testcase( pExpr->op==TK_EQ ); 1199 testcase( pExpr->op==TK_NE ); 1200 testcase( pExpr->op==TK_LT ); 1201 testcase( pExpr->op==TK_LE ); 1202 testcase( pExpr->op==TK_GT ); 1203 testcase( pExpr->op==TK_GE ); 1204 testcase( pExpr->op==TK_IS ); 1205 testcase( pExpr->op==TK_ISNOT ); 1206 testcase( pExpr->op==TK_BETWEEN ); 1207 sqlite3ErrorMsg(pParse, "row value misused"); 1208 } 1209 break; 1210 } 1211 } 1212 return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue; 1213 } 1214 1215 /* 1216 ** pEList is a list of expressions which are really the result set of the 1217 ** a SELECT statement. pE is a term in an ORDER BY or GROUP BY clause. 1218 ** This routine checks to see if pE is a simple identifier which corresponds 1219 ** to the AS-name of one of the terms of the expression list. If it is, 1220 ** this routine return an integer between 1 and N where N is the number of 1221 ** elements in pEList, corresponding to the matching entry. If there is 1222 ** no match, or if pE is not a simple identifier, then this routine 1223 ** return 0. 1224 ** 1225 ** pEList has been resolved. pE has not. 1226 */ 1227 static int resolveAsName( 1228 Parse *pParse, /* Parsing context for error messages */ 1229 ExprList *pEList, /* List of expressions to scan */ 1230 Expr *pE /* Expression we are trying to match */ 1231 ){ 1232 int i; /* Loop counter */ 1233 1234 UNUSED_PARAMETER(pParse); 1235 1236 if( pE->op==TK_ID ){ 1237 const char *zCol; 1238 assert( !ExprHasProperty(pE, EP_IntValue) ); 1239 zCol = pE->u.zToken; 1240 for(i=0; i<pEList->nExpr; i++){ 1241 if( pEList->a[i].eEName==ENAME_NAME 1242 && sqlite3_stricmp(pEList->a[i].zEName, zCol)==0 1243 ){ 1244 return i+1; 1245 } 1246 } 1247 } 1248 return 0; 1249 } 1250 1251 /* 1252 ** pE is a pointer to an expression which is a single term in the 1253 ** ORDER BY of a compound SELECT. The expression has not been 1254 ** name resolved. 1255 ** 1256 ** At the point this routine is called, we already know that the 1257 ** ORDER BY term is not an integer index into the result set. That 1258 ** case is handled by the calling routine. 1259 ** 1260 ** Attempt to match pE against result set columns in the left-most 1261 ** SELECT statement. Return the index i of the matching column, 1262 ** as an indication to the caller that it should sort by the i-th column. 1263 ** The left-most column is 1. In other words, the value returned is the 1264 ** same integer value that would be used in the SQL statement to indicate 1265 ** the column. 1266 ** 1267 ** If there is no match, return 0. Return -1 if an error occurs. 1268 */ 1269 static int resolveOrderByTermToExprList( 1270 Parse *pParse, /* Parsing context for error messages */ 1271 Select *pSelect, /* The SELECT statement with the ORDER BY clause */ 1272 Expr *pE /* The specific ORDER BY term */ 1273 ){ 1274 int i; /* Loop counter */ 1275 ExprList *pEList; /* The columns of the result set */ 1276 NameContext nc; /* Name context for resolving pE */ 1277 sqlite3 *db; /* Database connection */ 1278 int rc; /* Return code from subprocedures */ 1279 u8 savedSuppErr; /* Saved value of db->suppressErr */ 1280 1281 assert( sqlite3ExprIsInteger(pE, &i)==0 ); 1282 pEList = pSelect->pEList; 1283 1284 /* Resolve all names in the ORDER BY term expression 1285 */ 1286 memset(&nc, 0, sizeof(nc)); 1287 nc.pParse = pParse; 1288 nc.pSrcList = pSelect->pSrc; 1289 nc.uNC.pEList = pEList; 1290 nc.ncFlags = NC_AllowAgg|NC_UEList|NC_NoSelect; 1291 nc.nNcErr = 0; 1292 db = pParse->db; 1293 savedSuppErr = db->suppressErr; 1294 db->suppressErr = 1; 1295 rc = sqlite3ResolveExprNames(&nc, pE); 1296 db->suppressErr = savedSuppErr; 1297 if( rc ) return 0; 1298 1299 /* Try to match the ORDER BY expression against an expression 1300 ** in the result set. Return an 1-based index of the matching 1301 ** result-set entry. 1302 */ 1303 for(i=0; i<pEList->nExpr; i++){ 1304 if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){ 1305 return i+1; 1306 } 1307 } 1308 1309 /* If no match, return 0. */ 1310 return 0; 1311 } 1312 1313 /* 1314 ** Generate an ORDER BY or GROUP BY term out-of-range error. 1315 */ 1316 static void resolveOutOfRangeError( 1317 Parse *pParse, /* The error context into which to write the error */ 1318 const char *zType, /* "ORDER" or "GROUP" */ 1319 int i, /* The index (1-based) of the term out of range */ 1320 int mx /* Largest permissible value of i */ 1321 ){ 1322 sqlite3ErrorMsg(pParse, 1323 "%r %s BY term out of range - should be " 1324 "between 1 and %d", i, zType, mx); 1325 } 1326 1327 /* 1328 ** Analyze the ORDER BY clause in a compound SELECT statement. Modify 1329 ** each term of the ORDER BY clause is a constant integer between 1 1330 ** and N where N is the number of columns in the compound SELECT. 1331 ** 1332 ** ORDER BY terms that are already an integer between 1 and N are 1333 ** unmodified. ORDER BY terms that are integers outside the range of 1334 ** 1 through N generate an error. ORDER BY terms that are expressions 1335 ** are matched against result set expressions of compound SELECT 1336 ** beginning with the left-most SELECT and working toward the right. 1337 ** At the first match, the ORDER BY expression is transformed into 1338 ** the integer column number. 1339 ** 1340 ** Return the number of errors seen. 1341 */ 1342 static int resolveCompoundOrderBy( 1343 Parse *pParse, /* Parsing context. Leave error messages here */ 1344 Select *pSelect /* The SELECT statement containing the ORDER BY */ 1345 ){ 1346 int i; 1347 ExprList *pOrderBy; 1348 ExprList *pEList; 1349 sqlite3 *db; 1350 int moreToDo = 1; 1351 1352 pOrderBy = pSelect->pOrderBy; 1353 if( pOrderBy==0 ) return 0; 1354 db = pParse->db; 1355 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1356 sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause"); 1357 return 1; 1358 } 1359 for(i=0; i<pOrderBy->nExpr; i++){ 1360 pOrderBy->a[i].done = 0; 1361 } 1362 pSelect->pNext = 0; 1363 while( pSelect->pPrior ){ 1364 pSelect->pPrior->pNext = pSelect; 1365 pSelect = pSelect->pPrior; 1366 } 1367 while( pSelect && moreToDo ){ 1368 struct ExprList_item *pItem; 1369 moreToDo = 0; 1370 pEList = pSelect->pEList; 1371 assert( pEList!=0 ); 1372 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1373 int iCol = -1; 1374 Expr *pE, *pDup; 1375 if( pItem->done ) continue; 1376 pE = sqlite3ExprSkipCollateAndLikely(pItem->pExpr); 1377 if( NEVER(pE==0) ) continue; 1378 if( sqlite3ExprIsInteger(pE, &iCol) ){ 1379 if( iCol<=0 || iCol>pEList->nExpr ){ 1380 resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr); 1381 return 1; 1382 } 1383 }else{ 1384 iCol = resolveAsName(pParse, pEList, pE); 1385 if( iCol==0 ){ 1386 /* Now test if expression pE matches one of the values returned 1387 ** by pSelect. In the usual case this is done by duplicating the 1388 ** expression, resolving any symbols in it, and then comparing 1389 ** it against each expression returned by the SELECT statement. 1390 ** Once the comparisons are finished, the duplicate expression 1391 ** is deleted. 1392 ** 1393 ** If this is running as part of an ALTER TABLE operation and 1394 ** the symbols resolve successfully, also resolve the symbols in the 1395 ** actual expression. This allows the code in alter.c to modify 1396 ** column references within the ORDER BY expression as required. */ 1397 pDup = sqlite3ExprDup(db, pE, 0); 1398 if( !db->mallocFailed ){ 1399 assert(pDup); 1400 iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup); 1401 if( IN_RENAME_OBJECT && iCol>0 ){ 1402 resolveOrderByTermToExprList(pParse, pSelect, pE); 1403 } 1404 } 1405 sqlite3ExprDelete(db, pDup); 1406 } 1407 } 1408 if( iCol>0 ){ 1409 /* Convert the ORDER BY term into an integer column number iCol, 1410 ** taking care to preserve the COLLATE clause if it exists. */ 1411 if( !IN_RENAME_OBJECT ){ 1412 Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); 1413 if( pNew==0 ) return 1; 1414 pNew->flags |= EP_IntValue; 1415 pNew->u.iValue = iCol; 1416 if( pItem->pExpr==pE ){ 1417 pItem->pExpr = pNew; 1418 }else{ 1419 Expr *pParent = pItem->pExpr; 1420 assert( pParent->op==TK_COLLATE ); 1421 while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft; 1422 assert( pParent->pLeft==pE ); 1423 pParent->pLeft = pNew; 1424 } 1425 sqlite3ExprDelete(db, pE); 1426 pItem->u.x.iOrderByCol = (u16)iCol; 1427 } 1428 pItem->done = 1; 1429 }else{ 1430 moreToDo = 1; 1431 } 1432 } 1433 pSelect = pSelect->pNext; 1434 } 1435 for(i=0; i<pOrderBy->nExpr; i++){ 1436 if( pOrderBy->a[i].done==0 ){ 1437 sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any " 1438 "column in the result set", i+1); 1439 return 1; 1440 } 1441 } 1442 return 0; 1443 } 1444 1445 /* 1446 ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of 1447 ** the SELECT statement pSelect. If any term is reference to a 1448 ** result set expression (as determined by the ExprList.a.u.x.iOrderByCol 1449 ** field) then convert that term into a copy of the corresponding result set 1450 ** column. 1451 ** 1452 ** If any errors are detected, add an error message to pParse and 1453 ** return non-zero. Return zero if no errors are seen. 1454 */ 1455 int sqlite3ResolveOrderGroupBy( 1456 Parse *pParse, /* Parsing context. Leave error messages here */ 1457 Select *pSelect, /* The SELECT statement containing the clause */ 1458 ExprList *pOrderBy, /* The ORDER BY or GROUP BY clause to be processed */ 1459 const char *zType /* "ORDER" or "GROUP" */ 1460 ){ 1461 int i; 1462 sqlite3 *db = pParse->db; 1463 ExprList *pEList; 1464 struct ExprList_item *pItem; 1465 1466 if( pOrderBy==0 || pParse->db->mallocFailed || IN_RENAME_OBJECT ) return 0; 1467 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1468 sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType); 1469 return 1; 1470 } 1471 pEList = pSelect->pEList; 1472 assert( pEList!=0 ); /* sqlite3SelectNew() guarantees this */ 1473 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1474 if( pItem->u.x.iOrderByCol ){ 1475 if( pItem->u.x.iOrderByCol>pEList->nExpr ){ 1476 resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr); 1477 return 1; 1478 } 1479 resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,0); 1480 } 1481 } 1482 return 0; 1483 } 1484 1485 #ifndef SQLITE_OMIT_WINDOWFUNC 1486 /* 1487 ** Walker callback for windowRemoveExprFromSelect(). 1488 */ 1489 static int resolveRemoveWindowsCb(Walker *pWalker, Expr *pExpr){ 1490 UNUSED_PARAMETER(pWalker); 1491 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1492 Window *pWin = pExpr->y.pWin; 1493 sqlite3WindowUnlinkFromSelect(pWin); 1494 } 1495 return WRC_Continue; 1496 } 1497 1498 /* 1499 ** Remove any Window objects owned by the expression pExpr from the 1500 ** Select.pWin list of Select object pSelect. 1501 */ 1502 static void windowRemoveExprFromSelect(Select *pSelect, Expr *pExpr){ 1503 if( pSelect->pWin ){ 1504 Walker sWalker; 1505 memset(&sWalker, 0, sizeof(Walker)); 1506 sWalker.xExprCallback = resolveRemoveWindowsCb; 1507 sWalker.u.pSelect = pSelect; 1508 sqlite3WalkExpr(&sWalker, pExpr); 1509 } 1510 } 1511 #else 1512 # define windowRemoveExprFromSelect(a, b) 1513 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1514 1515 /* 1516 ** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect. 1517 ** The Name context of the SELECT statement is pNC. zType is either 1518 ** "ORDER" or "GROUP" depending on which type of clause pOrderBy is. 1519 ** 1520 ** This routine resolves each term of the clause into an expression. 1521 ** If the order-by term is an integer I between 1 and N (where N is the 1522 ** number of columns in the result set of the SELECT) then the expression 1523 ** in the resolution is a copy of the I-th result-set expression. If 1524 ** the order-by term is an identifier that corresponds to the AS-name of 1525 ** a result-set expression, then the term resolves to a copy of the 1526 ** result-set expression. Otherwise, the expression is resolved in 1527 ** the usual way - using sqlite3ResolveExprNames(). 1528 ** 1529 ** This routine returns the number of errors. If errors occur, then 1530 ** an appropriate error message might be left in pParse. (OOM errors 1531 ** excepted.) 1532 */ 1533 static int resolveOrderGroupBy( 1534 NameContext *pNC, /* The name context of the SELECT statement */ 1535 Select *pSelect, /* The SELECT statement holding pOrderBy */ 1536 ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */ 1537 const char *zType /* Either "ORDER" or "GROUP", as appropriate */ 1538 ){ 1539 int i, j; /* Loop counters */ 1540 int iCol; /* Column number */ 1541 struct ExprList_item *pItem; /* A term of the ORDER BY clause */ 1542 Parse *pParse; /* Parsing context */ 1543 int nResult; /* Number of terms in the result set */ 1544 1545 assert( pOrderBy!=0 ); 1546 nResult = pSelect->pEList->nExpr; 1547 pParse = pNC->pParse; 1548 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1549 Expr *pE = pItem->pExpr; 1550 Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pE); 1551 if( NEVER(pE2==0) ) continue; 1552 if( zType[0]!='G' ){ 1553 iCol = resolveAsName(pParse, pSelect->pEList, pE2); 1554 if( iCol>0 ){ 1555 /* If an AS-name match is found, mark this ORDER BY column as being 1556 ** a copy of the iCol-th result-set column. The subsequent call to 1557 ** sqlite3ResolveOrderGroupBy() will convert the expression to a 1558 ** copy of the iCol-th result-set expression. */ 1559 pItem->u.x.iOrderByCol = (u16)iCol; 1560 continue; 1561 } 1562 } 1563 if( sqlite3ExprIsInteger(pE2, &iCol) ){ 1564 /* The ORDER BY term is an integer constant. Again, set the column 1565 ** number so that sqlite3ResolveOrderGroupBy() will convert the 1566 ** order-by term to a copy of the result-set expression */ 1567 if( iCol<1 || iCol>0xffff ){ 1568 resolveOutOfRangeError(pParse, zType, i+1, nResult); 1569 return 1; 1570 } 1571 pItem->u.x.iOrderByCol = (u16)iCol; 1572 continue; 1573 } 1574 1575 /* Otherwise, treat the ORDER BY term as an ordinary expression */ 1576 pItem->u.x.iOrderByCol = 0; 1577 if( sqlite3ResolveExprNames(pNC, pE) ){ 1578 return 1; 1579 } 1580 for(j=0; j<pSelect->pEList->nExpr; j++){ 1581 if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){ 1582 /* Since this expresion is being changed into a reference 1583 ** to an identical expression in the result set, remove all Window 1584 ** objects belonging to the expression from the Select.pWin list. */ 1585 windowRemoveExprFromSelect(pSelect, pE); 1586 pItem->u.x.iOrderByCol = j+1; 1587 } 1588 } 1589 } 1590 return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType); 1591 } 1592 1593 /* 1594 ** Resolve names in the SELECT statement p and all of its descendants. 1595 */ 1596 static int resolveSelectStep(Walker *pWalker, Select *p){ 1597 NameContext *pOuterNC; /* Context that contains this SELECT */ 1598 NameContext sNC; /* Name context of this SELECT */ 1599 int isCompound; /* True if p is a compound select */ 1600 int nCompound; /* Number of compound terms processed so far */ 1601 Parse *pParse; /* Parsing context */ 1602 int i; /* Loop counter */ 1603 ExprList *pGroupBy; /* The GROUP BY clause */ 1604 Select *pLeftmost; /* Left-most of SELECT of a compound */ 1605 sqlite3 *db; /* Database connection */ 1606 1607 1608 assert( p!=0 ); 1609 if( p->selFlags & SF_Resolved ){ 1610 return WRC_Prune; 1611 } 1612 pOuterNC = pWalker->u.pNC; 1613 pParse = pWalker->pParse; 1614 db = pParse->db; 1615 1616 /* Normally sqlite3SelectExpand() will be called first and will have 1617 ** already expanded this SELECT. However, if this is a subquery within 1618 ** an expression, sqlite3ResolveExprNames() will be called without a 1619 ** prior call to sqlite3SelectExpand(). When that happens, let 1620 ** sqlite3SelectPrep() do all of the processing for this SELECT. 1621 ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and 1622 ** this routine in the correct order. 1623 */ 1624 if( (p->selFlags & SF_Expanded)==0 ){ 1625 sqlite3SelectPrep(pParse, p, pOuterNC); 1626 return (pParse->nErr || db->mallocFailed) ? WRC_Abort : WRC_Prune; 1627 } 1628 1629 isCompound = p->pPrior!=0; 1630 nCompound = 0; 1631 pLeftmost = p; 1632 while( p ){ 1633 assert( (p->selFlags & SF_Expanded)!=0 ); 1634 assert( (p->selFlags & SF_Resolved)==0 ); 1635 assert( db->suppressErr==0 ); /* SF_Resolved not set if errors suppressed */ 1636 p->selFlags |= SF_Resolved; 1637 1638 1639 /* Resolve the expressions in the LIMIT and OFFSET clauses. These 1640 ** are not allowed to refer to any names, so pass an empty NameContext. 1641 */ 1642 memset(&sNC, 0, sizeof(sNC)); 1643 sNC.pParse = pParse; 1644 sNC.pWinSelect = p; 1645 if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){ 1646 return WRC_Abort; 1647 } 1648 1649 /* If the SF_Converted flags is set, then this Select object was 1650 ** was created by the convertCompoundSelectToSubquery() function. 1651 ** In this case the ORDER BY clause (p->pOrderBy) should be resolved 1652 ** as if it were part of the sub-query, not the parent. This block 1653 ** moves the pOrderBy down to the sub-query. It will be moved back 1654 ** after the names have been resolved. */ 1655 if( p->selFlags & SF_Converted ){ 1656 Select *pSub = p->pSrc->a[0].pSelect; 1657 assert( p->pSrc->nSrc==1 && p->pOrderBy ); 1658 assert( pSub->pPrior && pSub->pOrderBy==0 ); 1659 pSub->pOrderBy = p->pOrderBy; 1660 p->pOrderBy = 0; 1661 } 1662 1663 /* Recursively resolve names in all subqueries in the FROM clause 1664 */ 1665 for(i=0; i<p->pSrc->nSrc; i++){ 1666 SrcItem *pItem = &p->pSrc->a[i]; 1667 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){ 1668 int nRef = pOuterNC ? pOuterNC->nRef : 0; 1669 const char *zSavedContext = pParse->zAuthContext; 1670 1671 if( pItem->zName ) pParse->zAuthContext = pItem->zName; 1672 sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC); 1673 pParse->zAuthContext = zSavedContext; 1674 if( pParse->nErr || db->mallocFailed ) return WRC_Abort; 1675 1676 /* If the number of references to the outer context changed when 1677 ** expressions in the sub-select were resolved, the sub-select 1678 ** is correlated. It is not required to check the refcount on any 1679 ** but the innermost outer context object, as lookupName() increments 1680 ** the refcount on all contexts between the current one and the 1681 ** context containing the column when it resolves a name. */ 1682 if( pOuterNC ){ 1683 assert( pItem->fg.isCorrelated==0 && pOuterNC->nRef>=nRef ); 1684 pItem->fg.isCorrelated = (pOuterNC->nRef>nRef); 1685 } 1686 } 1687 } 1688 1689 /* Set up the local name-context to pass to sqlite3ResolveExprNames() to 1690 ** resolve the result-set expression list. 1691 */ 1692 sNC.ncFlags = NC_AllowAgg|NC_AllowWin; 1693 sNC.pSrcList = p->pSrc; 1694 sNC.pNext = pOuterNC; 1695 1696 /* Resolve names in the result set. */ 1697 if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort; 1698 sNC.ncFlags &= ~NC_AllowWin; 1699 1700 /* If there are no aggregate functions in the result-set, and no GROUP BY 1701 ** expression, do not allow aggregates in any of the other expressions. 1702 */ 1703 assert( (p->selFlags & SF_Aggregate)==0 ); 1704 pGroupBy = p->pGroupBy; 1705 if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){ 1706 assert( NC_MinMaxAgg==SF_MinMaxAgg ); 1707 assert( NC_OrderAgg==SF_OrderByReqd ); 1708 p->selFlags |= SF_Aggregate | (sNC.ncFlags&(NC_MinMaxAgg|NC_OrderAgg)); 1709 }else{ 1710 sNC.ncFlags &= ~NC_AllowAgg; 1711 } 1712 1713 /* Add the output column list to the name-context before parsing the 1714 ** other expressions in the SELECT statement. This is so that 1715 ** expressions in the WHERE clause (etc.) can refer to expressions by 1716 ** aliases in the result set. 1717 ** 1718 ** Minor point: If this is the case, then the expression will be 1719 ** re-evaluated for each reference to it. 1720 */ 1721 assert( (sNC.ncFlags & (NC_UAggInfo|NC_UUpsert|NC_UBaseReg))==0 ); 1722 sNC.uNC.pEList = p->pEList; 1723 sNC.ncFlags |= NC_UEList; 1724 if( p->pHaving ){ 1725 if( !pGroupBy ){ 1726 sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING"); 1727 return WRC_Abort; 1728 } 1729 if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort; 1730 } 1731 if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort; 1732 1733 /* Resolve names in table-valued-function arguments */ 1734 for(i=0; i<p->pSrc->nSrc; i++){ 1735 SrcItem *pItem = &p->pSrc->a[i]; 1736 if( pItem->fg.isTabFunc 1737 && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 1738 ){ 1739 return WRC_Abort; 1740 } 1741 } 1742 1743 #ifndef SQLITE_OMIT_WINDOWFUNC 1744 if( IN_RENAME_OBJECT ){ 1745 Window *pWin; 1746 for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){ 1747 if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy) 1748 || sqlite3ResolveExprListNames(&sNC, pWin->pPartition) 1749 ){ 1750 return WRC_Abort; 1751 } 1752 } 1753 } 1754 #endif 1755 1756 /* The ORDER BY and GROUP BY clauses may not refer to terms in 1757 ** outer queries 1758 */ 1759 sNC.pNext = 0; 1760 sNC.ncFlags |= NC_AllowAgg|NC_AllowWin; 1761 1762 /* If this is a converted compound query, move the ORDER BY clause from 1763 ** the sub-query back to the parent query. At this point each term 1764 ** within the ORDER BY clause has been transformed to an integer value. 1765 ** These integers will be replaced by copies of the corresponding result 1766 ** set expressions by the call to resolveOrderGroupBy() below. */ 1767 if( p->selFlags & SF_Converted ){ 1768 Select *pSub = p->pSrc->a[0].pSelect; 1769 p->pOrderBy = pSub->pOrderBy; 1770 pSub->pOrderBy = 0; 1771 } 1772 1773 /* Process the ORDER BY clause for singleton SELECT statements. 1774 ** The ORDER BY clause for compounds SELECT statements is handled 1775 ** below, after all of the result-sets for all of the elements of 1776 ** the compound have been resolved. 1777 ** 1778 ** If there is an ORDER BY clause on a term of a compound-select other 1779 ** than the right-most term, then that is a syntax error. But the error 1780 ** is not detected until much later, and so we need to go ahead and 1781 ** resolve those symbols on the incorrect ORDER BY for consistency. 1782 */ 1783 if( p->pOrderBy!=0 1784 && isCompound<=nCompound /* Defer right-most ORDER BY of a compound */ 1785 && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") 1786 ){ 1787 return WRC_Abort; 1788 } 1789 if( db->mallocFailed ){ 1790 return WRC_Abort; 1791 } 1792 sNC.ncFlags &= ~NC_AllowWin; 1793 1794 /* Resolve the GROUP BY clause. At the same time, make sure 1795 ** the GROUP BY clause does not contain aggregate functions. 1796 */ 1797 if( pGroupBy ){ 1798 struct ExprList_item *pItem; 1799 1800 if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){ 1801 return WRC_Abort; 1802 } 1803 for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){ 1804 if( ExprHasProperty(pItem->pExpr, EP_Agg) ){ 1805 sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in " 1806 "the GROUP BY clause"); 1807 return WRC_Abort; 1808 } 1809 } 1810 } 1811 1812 /* If this is part of a compound SELECT, check that it has the right 1813 ** number of expressions in the select list. */ 1814 if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){ 1815 sqlite3SelectWrongNumTermsError(pParse, p->pNext); 1816 return WRC_Abort; 1817 } 1818 1819 /* Advance to the next term of the compound 1820 */ 1821 p = p->pPrior; 1822 nCompound++; 1823 } 1824 1825 /* Resolve the ORDER BY on a compound SELECT after all terms of 1826 ** the compound have been resolved. 1827 */ 1828 if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){ 1829 return WRC_Abort; 1830 } 1831 1832 return WRC_Prune; 1833 } 1834 1835 /* 1836 ** This routine walks an expression tree and resolves references to 1837 ** table columns and result-set columns. At the same time, do error 1838 ** checking on function usage and set a flag if any aggregate functions 1839 ** are seen. 1840 ** 1841 ** To resolve table columns references we look for nodes (or subtrees) of the 1842 ** form X.Y.Z or Y.Z or just Z where 1843 ** 1844 ** X: The name of a database. Ex: "main" or "temp" or 1845 ** the symbolic name assigned to an ATTACH-ed database. 1846 ** 1847 ** Y: The name of a table in a FROM clause. Or in a trigger 1848 ** one of the special names "old" or "new". 1849 ** 1850 ** Z: The name of a column in table Y. 1851 ** 1852 ** The node at the root of the subtree is modified as follows: 1853 ** 1854 ** Expr.op Changed to TK_COLUMN 1855 ** Expr.pTab Points to the Table object for X.Y 1856 ** Expr.iColumn The column index in X.Y. -1 for the rowid. 1857 ** Expr.iTable The VDBE cursor number for X.Y 1858 ** 1859 ** 1860 ** To resolve result-set references, look for expression nodes of the 1861 ** form Z (with no X and Y prefix) where the Z matches the right-hand 1862 ** size of an AS clause in the result-set of a SELECT. The Z expression 1863 ** is replaced by a copy of the left-hand side of the result-set expression. 1864 ** Table-name and function resolution occurs on the substituted expression 1865 ** tree. For example, in: 1866 ** 1867 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x; 1868 ** 1869 ** The "x" term of the order by is replaced by "a+b" to render: 1870 ** 1871 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b; 1872 ** 1873 ** Function calls are checked to make sure that the function is 1874 ** defined and that the correct number of arguments are specified. 1875 ** If the function is an aggregate function, then the NC_HasAgg flag is 1876 ** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION. 1877 ** If an expression contains aggregate functions then the EP_Agg 1878 ** property on the expression is set. 1879 ** 1880 ** An error message is left in pParse if anything is amiss. The number 1881 ** if errors is returned. 1882 */ 1883 int sqlite3ResolveExprNames( 1884 NameContext *pNC, /* Namespace to resolve expressions in. */ 1885 Expr *pExpr /* The expression to be analyzed. */ 1886 ){ 1887 int savedHasAgg; 1888 Walker w; 1889 1890 if( pExpr==0 ) return SQLITE_OK; 1891 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1892 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1893 w.pParse = pNC->pParse; 1894 w.xExprCallback = resolveExprStep; 1895 w.xSelectCallback = (pNC->ncFlags & NC_NoSelect) ? 0 : resolveSelectStep; 1896 w.xSelectCallback2 = 0; 1897 w.u.pNC = pNC; 1898 #if SQLITE_MAX_EXPR_DEPTH>0 1899 w.pParse->nHeight += pExpr->nHeight; 1900 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1901 return SQLITE_ERROR; 1902 } 1903 #endif 1904 sqlite3WalkExpr(&w, pExpr); 1905 #if SQLITE_MAX_EXPR_DEPTH>0 1906 w.pParse->nHeight -= pExpr->nHeight; 1907 #endif 1908 assert( EP_Agg==NC_HasAgg ); 1909 assert( EP_Win==NC_HasWin ); 1910 testcase( pNC->ncFlags & NC_HasAgg ); 1911 testcase( pNC->ncFlags & NC_HasWin ); 1912 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1913 pNC->ncFlags |= savedHasAgg; 1914 return pNC->nNcErr>0 || w.pParse->nErr>0; 1915 } 1916 1917 /* 1918 ** Resolve all names for all expression in an expression list. This is 1919 ** just like sqlite3ResolveExprNames() except that it works for an expression 1920 ** list rather than a single expression. 1921 */ 1922 int sqlite3ResolveExprListNames( 1923 NameContext *pNC, /* Namespace to resolve expressions in. */ 1924 ExprList *pList /* The expression list to be analyzed. */ 1925 ){ 1926 int i; 1927 int savedHasAgg = 0; 1928 Walker w; 1929 if( pList==0 ) return WRC_Continue; 1930 w.pParse = pNC->pParse; 1931 w.xExprCallback = resolveExprStep; 1932 w.xSelectCallback = resolveSelectStep; 1933 w.xSelectCallback2 = 0; 1934 w.u.pNC = pNC; 1935 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1936 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1937 for(i=0; i<pList->nExpr; i++){ 1938 Expr *pExpr = pList->a[i].pExpr; 1939 if( pExpr==0 ) continue; 1940 #if SQLITE_MAX_EXPR_DEPTH>0 1941 w.pParse->nHeight += pExpr->nHeight; 1942 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1943 return WRC_Abort; 1944 } 1945 #endif 1946 sqlite3WalkExpr(&w, pExpr); 1947 #if SQLITE_MAX_EXPR_DEPTH>0 1948 w.pParse->nHeight -= pExpr->nHeight; 1949 #endif 1950 assert( EP_Agg==NC_HasAgg ); 1951 assert( EP_Win==NC_HasWin ); 1952 testcase( pNC->ncFlags & NC_HasAgg ); 1953 testcase( pNC->ncFlags & NC_HasWin ); 1954 if( pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg) ){ 1955 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1956 savedHasAgg |= pNC->ncFlags & 1957 (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1958 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); 1959 } 1960 if( w.pParse->nErr>0 ) return WRC_Abort; 1961 } 1962 pNC->ncFlags |= savedHasAgg; 1963 return WRC_Continue; 1964 } 1965 1966 /* 1967 ** Resolve all names in all expressions of a SELECT and in all 1968 ** decendents of the SELECT, including compounds off of p->pPrior, 1969 ** subqueries in expressions, and subqueries used as FROM clause 1970 ** terms. 1971 ** 1972 ** See sqlite3ResolveExprNames() for a description of the kinds of 1973 ** transformations that occur. 1974 ** 1975 ** All SELECT statements should have been expanded using 1976 ** sqlite3SelectExpand() prior to invoking this routine. 1977 */ 1978 void sqlite3ResolveSelectNames( 1979 Parse *pParse, /* The parser context */ 1980 Select *p, /* The SELECT statement being coded. */ 1981 NameContext *pOuterNC /* Name context for parent SELECT statement */ 1982 ){ 1983 Walker w; 1984 1985 assert( p!=0 ); 1986 w.xExprCallback = resolveExprStep; 1987 w.xSelectCallback = resolveSelectStep; 1988 w.xSelectCallback2 = 0; 1989 w.pParse = pParse; 1990 w.u.pNC = pOuterNC; 1991 sqlite3WalkSelect(&w, p); 1992 } 1993 1994 /* 1995 ** Resolve names in expressions that can only reference a single table 1996 ** or which cannot reference any tables at all. Examples: 1997 ** 1998 ** "type" flag 1999 ** ------------ 2000 ** (1) CHECK constraints NC_IsCheck 2001 ** (2) WHERE clauses on partial indices NC_PartIdx 2002 ** (3) Expressions in indexes on expressions NC_IdxExpr 2003 ** (4) Expression arguments to VACUUM INTO. 0 2004 ** (5) GENERATED ALWAYS as expressions NC_GenCol 2005 ** 2006 ** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN 2007 ** nodes of the expression is set to -1 and the Expr.iColumn value is 2008 ** set to the column number. In case (4), TK_COLUMN nodes cause an error. 2009 ** 2010 ** Any errors cause an error message to be set in pParse. 2011 */ 2012 int sqlite3ResolveSelfReference( 2013 Parse *pParse, /* Parsing context */ 2014 Table *pTab, /* The table being referenced, or NULL */ 2015 int type, /* NC_IsCheck, NC_PartIdx, NC_IdxExpr, NC_GenCol, or 0 */ 2016 Expr *pExpr, /* Expression to resolve. May be NULL. */ 2017 ExprList *pList /* Expression list to resolve. May be NULL. */ 2018 ){ 2019 SrcList sSrc; /* Fake SrcList for pParse->pNewTable */ 2020 NameContext sNC; /* Name context for pParse->pNewTable */ 2021 int rc; 2022 2023 assert( type==0 || pTab!=0 ); 2024 assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr 2025 || type==NC_GenCol || pTab==0 ); 2026 memset(&sNC, 0, sizeof(sNC)); 2027 memset(&sSrc, 0, sizeof(sSrc)); 2028 if( pTab ){ 2029 sSrc.nSrc = 1; 2030 sSrc.a[0].zName = pTab->zName; 2031 sSrc.a[0].pTab = pTab; 2032 sSrc.a[0].iCursor = -1; 2033 if( pTab->pSchema!=pParse->db->aDb[1].pSchema ){ 2034 /* Cause EP_FromDDL to be set on TK_FUNCTION nodes of non-TEMP 2035 ** schema elements */ 2036 type |= NC_FromDDL; 2037 } 2038 } 2039 sNC.pParse = pParse; 2040 sNC.pSrcList = &sSrc; 2041 sNC.ncFlags = type | NC_IsDDL; 2042 if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc; 2043 if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList); 2044 return rc; 2045 } 2046