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 ** Walk the expression tree pExpr and increase the aggregate function 21 ** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node. 22 ** This needs to occur when copying a TK_AGG_FUNCTION node from an 23 ** outer query into an inner subquery. 24 ** 25 ** incrAggFunctionDepth(pExpr,n) is the main routine. incrAggDepth(..) 26 ** is a helper function - a callback for the tree walker. 27 */ 28 static int incrAggDepth(Walker *pWalker, Expr *pExpr){ 29 if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n; 30 return WRC_Continue; 31 } 32 static void incrAggFunctionDepth(Expr *pExpr, int N){ 33 if( N>0 ){ 34 Walker w; 35 memset(&w, 0, sizeof(w)); 36 w.xExprCallback = incrAggDepth; 37 w.u.n = N; 38 sqlite3WalkExpr(&w, pExpr); 39 } 40 } 41 42 /* 43 ** Turn the pExpr expression into an alias for the iCol-th column of the 44 ** result set in pEList. 45 ** 46 ** If the reference is followed by a COLLATE operator, then make sure 47 ** the COLLATE operator is preserved. For example: 48 ** 49 ** SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase; 50 ** 51 ** Should be transformed into: 52 ** 53 ** SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase; 54 ** 55 ** The nSubquery parameter specifies how many levels of subquery the 56 ** alias is removed from the original expression. The usual value is 57 ** zero but it might be more if the alias is contained within a subquery 58 ** of the original expression. The Expr.op2 field of TK_AGG_FUNCTION 59 ** structures must be increased by the nSubquery amount. 60 */ 61 static void resolveAlias( 62 Parse *pParse, /* Parsing context */ 63 ExprList *pEList, /* A result set */ 64 int iCol, /* A column in the result set. 0..pEList->nExpr-1 */ 65 Expr *pExpr, /* Transform this into an alias to the result set */ 66 const char *zType, /* "GROUP" or "ORDER" or "" */ 67 int nSubquery /* Number of subqueries that the label is moving */ 68 ){ 69 Expr *pOrig; /* The iCol-th column of the result set */ 70 Expr *pDup; /* Copy of pOrig */ 71 sqlite3 *db; /* The database connection */ 72 73 assert( iCol>=0 && iCol<pEList->nExpr ); 74 pOrig = pEList->a[iCol].pExpr; 75 assert( pOrig!=0 ); 76 db = pParse->db; 77 pDup = sqlite3ExprDup(db, pOrig, 0); 78 if( pDup!=0 ){ 79 if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery); 80 if( pExpr->op==TK_COLLATE ){ 81 pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken); 82 } 83 84 /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 85 ** prevents ExprDelete() from deleting the Expr structure itself, 86 ** allowing it to be repopulated by the memcpy() on the following line. 87 ** The pExpr->u.zToken might point into memory that will be freed by the 88 ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to 89 ** make a copy of the token before doing the sqlite3DbFree(). 90 */ 91 ExprSetProperty(pExpr, EP_Static); 92 sqlite3ExprDelete(db, pExpr); 93 memcpy(pExpr, pDup, sizeof(*pExpr)); 94 if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){ 95 assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 ); 96 pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken); 97 pExpr->flags |= EP_MemToken; 98 } 99 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 100 if( pExpr->y.pWin!=0 ){ 101 pExpr->y.pWin->pOwner = pExpr; 102 }else{ 103 assert( db->mallocFailed ); 104 } 105 } 106 sqlite3DbFree(db, pDup); 107 } 108 ExprSetProperty(pExpr, EP_Alias); 109 } 110 111 112 /* 113 ** Return TRUE if the name zCol occurs anywhere in the USING clause. 114 ** 115 ** Return FALSE if the USING clause is NULL or if it does not contain 116 ** zCol. 117 */ 118 static int nameInUsingClause(IdList *pUsing, const char *zCol){ 119 if( pUsing ){ 120 int k; 121 for(k=0; k<pUsing->nId; k++){ 122 if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ) return 1; 123 } 124 } 125 return 0; 126 } 127 128 /* 129 ** Subqueries stores the original database, table and column names for their 130 ** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN". 131 ** Check to see if the zSpan given to this routine matches the zDb, zTab, 132 ** and zCol. If any of zDb, zTab, and zCol are NULL then those fields will 133 ** match anything. 134 */ 135 int sqlite3MatchEName( 136 const struct ExprList_item *pItem, 137 const char *zCol, 138 const char *zTab, 139 const char *zDb 140 ){ 141 int n; 142 const char *zSpan; 143 if( NEVER(pItem->eEName!=ENAME_TAB) ) return 0; 144 zSpan = pItem->zEName; 145 for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} 146 if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){ 147 return 0; 148 } 149 zSpan += n+1; 150 for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} 151 if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){ 152 return 0; 153 } 154 zSpan += n+1; 155 if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){ 156 return 0; 157 } 158 return 1; 159 } 160 161 /* 162 ** Return TRUE if the double-quoted string mis-feature should be supported. 163 */ 164 static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){ 165 if( db->init.busy ) return 1; /* Always support for legacy schemas */ 166 if( pTopNC->ncFlags & NC_IsDDL ){ 167 /* Currently parsing a DDL statement */ 168 if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){ 169 return 1; 170 } 171 return (db->flags & SQLITE_DqsDDL)!=0; 172 }else{ 173 /* Currently parsing a DML statement */ 174 return (db->flags & SQLITE_DqsDML)!=0; 175 } 176 } 177 178 /* 179 ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up 180 ** that name in the set of source tables in pSrcList and make the pExpr 181 ** expression node refer back to that source column. The following changes 182 ** are made to pExpr: 183 ** 184 ** pExpr->iDb Set the index in db->aDb[] of the database X 185 ** (even if X is implied). 186 ** pExpr->iTable Set to the cursor number for the table obtained 187 ** from pSrcList. 188 ** pExpr->y.pTab Points to the Table structure of X.Y (even if 189 ** X and/or Y are implied.) 190 ** pExpr->iColumn Set to the column number within the table. 191 ** pExpr->op Set to TK_COLUMN. 192 ** pExpr->pLeft Any expression this points to is deleted 193 ** pExpr->pRight Any expression this points to is deleted. 194 ** 195 ** The zDb variable is the name of the database (the "X"). This value may be 196 ** NULL meaning that name is of the form Y.Z or Z. Any available database 197 ** can be used. The zTable variable is the name of the table (the "Y"). This 198 ** value can be NULL if zDb is also NULL. If zTable is NULL it 199 ** means that the form of the name is Z and that columns from any table 200 ** can be used. 201 ** 202 ** If the name cannot be resolved unambiguously, leave an error message 203 ** in pParse and return WRC_Abort. Return WRC_Prune on success. 204 */ 205 static int lookupName( 206 Parse *pParse, /* The parsing context */ 207 const char *zDb, /* Name of the database containing table, or NULL */ 208 const char *zTab, /* Name of table containing column, or NULL */ 209 const char *zCol, /* Name of the column. */ 210 NameContext *pNC, /* The name context used to resolve the name */ 211 Expr *pExpr /* Make this EXPR node point to the selected column */ 212 ){ 213 int i, j; /* Loop counters */ 214 int cnt = 0; /* Number of matching column names */ 215 int cntTab = 0; /* Number of matching table names */ 216 int nSubquery = 0; /* How many levels of subquery */ 217 sqlite3 *db = pParse->db; /* The database connection */ 218 struct SrcList_item *pItem; /* Use for looping over pSrcList items */ 219 struct SrcList_item *pMatch = 0; /* The matching pSrcList item */ 220 NameContext *pTopNC = pNC; /* First namecontext in the list */ 221 Schema *pSchema = 0; /* Schema of the expression */ 222 int eNewExprOp = TK_COLUMN; /* New value for pExpr->op on success */ 223 Table *pTab = 0; /* Table hold the row */ 224 Column *pCol; /* A column of pTab */ 225 226 assert( pNC ); /* the name context cannot be NULL. */ 227 assert( zCol ); /* The Z in X.Y.Z cannot be NULL */ 228 assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) ); 229 230 /* Initialize the node to no-match */ 231 pExpr->iTable = -1; 232 ExprSetVVAProperty(pExpr, EP_NoReduce); 233 234 /* Translate the schema name in zDb into a pointer to the corresponding 235 ** schema. If not found, pSchema will remain NULL and nothing will match 236 ** resulting in an appropriate error message toward the end of this routine 237 */ 238 if( zDb ){ 239 testcase( pNC->ncFlags & NC_PartIdx ); 240 testcase( pNC->ncFlags & NC_IsCheck ); 241 if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){ 242 /* Silently ignore database qualifiers inside CHECK constraints and 243 ** partial indices. Do not raise errors because that might break 244 ** legacy and because it does not hurt anything to just ignore the 245 ** database name. */ 246 zDb = 0; 247 }else{ 248 for(i=0; i<db->nDb; i++){ 249 assert( db->aDb[i].zDbSName ); 250 if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){ 251 pSchema = db->aDb[i].pSchema; 252 break; 253 } 254 } 255 } 256 } 257 258 /* Start at the inner-most context and move outward until a match is found */ 259 assert( pNC && cnt==0 ); 260 do{ 261 ExprList *pEList; 262 SrcList *pSrcList = pNC->pSrcList; 263 264 if( pSrcList ){ 265 for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ 266 pTab = pItem->pTab; 267 assert( pTab!=0 && pTab->zName!=0 ); 268 assert( pTab->nCol>0 ); 269 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){ 270 int hit = 0; 271 pEList = pItem->pSelect->pEList; 272 for(j=0; j<pEList->nExpr; j++){ 273 if( sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){ 274 cnt++; 275 cntTab = 2; 276 pMatch = pItem; 277 pExpr->iColumn = j; 278 hit = 1; 279 } 280 } 281 if( hit || zTab==0 ) continue; 282 } 283 if( zDb && pTab->pSchema!=pSchema ){ 284 continue; 285 } 286 if( zTab ){ 287 const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName; 288 assert( zTabName!=0 ); 289 if( sqlite3StrICmp(zTabName, zTab)!=0 ){ 290 continue; 291 } 292 if( IN_RENAME_OBJECT && pItem->zAlias ){ 293 sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab); 294 } 295 } 296 if( 0==(cntTab++) ){ 297 pMatch = pItem; 298 } 299 for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ 300 if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ 301 /* If there has been exactly one prior match and this match 302 ** is for the right-hand table of a NATURAL JOIN or is in a 303 ** USING clause, then skip this match. 304 */ 305 if( cnt==1 ){ 306 if( pItem->fg.jointype & JT_NATURAL ) continue; 307 if( nameInUsingClause(pItem->pUsing, zCol) ) continue; 308 } 309 cnt++; 310 pMatch = pItem; 311 /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ 312 pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j; 313 break; 314 } 315 } 316 } 317 if( pMatch ){ 318 pExpr->iTable = pMatch->iCursor; 319 pExpr->y.pTab = pMatch->pTab; 320 /* RIGHT JOIN not (yet) supported */ 321 assert( (pMatch->fg.jointype & JT_RIGHT)==0 ); 322 if( (pMatch->fg.jointype & JT_LEFT)!=0 ){ 323 ExprSetProperty(pExpr, EP_CanBeNull); 324 } 325 pSchema = pExpr->y.pTab->pSchema; 326 } 327 } /* if( pSrcList ) */ 328 329 #if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) 330 /* If we have not already resolved the name, then maybe 331 ** it is a new.* or old.* trigger argument reference. Or 332 ** maybe it is an excluded.* from an upsert. 333 */ 334 if( zDb==0 && zTab!=0 && cntTab==0 ){ 335 pTab = 0; 336 #ifndef SQLITE_OMIT_TRIGGER 337 if( pParse->pTriggerTab!=0 ){ 338 int op = pParse->eTriggerOp; 339 assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT ); 340 if( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){ 341 pExpr->iTable = 1; 342 pTab = pParse->pTriggerTab; 343 }else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){ 344 pExpr->iTable = 0; 345 pTab = pParse->pTriggerTab; 346 } 347 } 348 #endif /* SQLITE_OMIT_TRIGGER */ 349 #ifndef SQLITE_OMIT_UPSERT 350 if( (pNC->ncFlags & NC_UUpsert)!=0 ){ 351 Upsert *pUpsert = pNC->uNC.pUpsert; 352 if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){ 353 pTab = pUpsert->pUpsertSrc->a[0].pTab; 354 pExpr->iTable = 2; 355 } 356 } 357 #endif /* SQLITE_OMIT_UPSERT */ 358 359 if( pTab ){ 360 int iCol; 361 pSchema = pTab->pSchema; 362 cntTab++; 363 for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){ 364 if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ 365 if( iCol==pTab->iPKey ){ 366 iCol = -1; 367 } 368 break; 369 } 370 } 371 if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){ 372 /* IMP: R-51414-32910 */ 373 iCol = -1; 374 } 375 if( iCol<pTab->nCol ){ 376 cnt++; 377 #ifndef SQLITE_OMIT_UPSERT 378 if( pExpr->iTable==2 ){ 379 testcase( iCol==(-1) ); 380 if( IN_RENAME_OBJECT ){ 381 pExpr->iColumn = iCol; 382 pExpr->y.pTab = pTab; 383 eNewExprOp = TK_COLUMN; 384 }else{ 385 pExpr->iTable = pNC->uNC.pUpsert->regData + iCol; 386 eNewExprOp = TK_REGISTER; 387 ExprSetProperty(pExpr, EP_Alias); 388 } 389 }else 390 #endif /* SQLITE_OMIT_UPSERT */ 391 { 392 #ifndef SQLITE_OMIT_TRIGGER 393 if( iCol<0 ){ 394 pExpr->affExpr = SQLITE_AFF_INTEGER; 395 }else if( pExpr->iTable==0 ){ 396 testcase( iCol==31 ); 397 testcase( iCol==32 ); 398 pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 399 }else{ 400 testcase( iCol==31 ); 401 testcase( iCol==32 ); 402 pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); 403 } 404 pExpr->y.pTab = pTab; 405 pExpr->iColumn = (i16)iCol; 406 eNewExprOp = TK_TRIGGER; 407 #endif /* SQLITE_OMIT_TRIGGER */ 408 } 409 } 410 } 411 } 412 #endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */ 413 414 /* 415 ** Perhaps the name is a reference to the ROWID 416 */ 417 if( cnt==0 418 && cntTab==1 419 && pMatch 420 && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0 421 && sqlite3IsRowid(zCol) 422 && VisibleRowid(pMatch->pTab) 423 ){ 424 cnt = 1; 425 pExpr->iColumn = -1; 426 pExpr->affExpr = SQLITE_AFF_INTEGER; 427 } 428 429 /* 430 ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z 431 ** might refer to an result-set alias. This happens, for example, when 432 ** we are resolving names in the WHERE clause of the following command: 433 ** 434 ** SELECT a+b AS x FROM table WHERE x<10; 435 ** 436 ** In cases like this, replace pExpr with a copy of the expression that 437 ** forms the result set entry ("a+b" in the example) and return immediately. 438 ** Note that the expression in the result set should have already been 439 ** resolved by the time the WHERE clause is resolved. 440 ** 441 ** The ability to use an output result-set column in the WHERE, GROUP BY, 442 ** or HAVING clauses, or as part of a larger expression in the ORDER BY 443 ** clause is not standard SQL. This is a (goofy) SQLite extension, that 444 ** is supported for backwards compatibility only. Hence, we issue a warning 445 ** on sqlite3_log() whenever the capability is used. 446 */ 447 if( (pNC->ncFlags & NC_UEList)!=0 448 && cnt==0 449 && zTab==0 450 ){ 451 pEList = pNC->uNC.pEList; 452 assert( pEList!=0 ); 453 for(j=0; j<pEList->nExpr; j++){ 454 char *zAs = pEList->a[j].zEName; 455 if( pEList->a[j].eEName==ENAME_NAME 456 && sqlite3_stricmp(zAs, zCol)==0 457 ){ 458 Expr *pOrig; 459 assert( pExpr->pLeft==0 && pExpr->pRight==0 ); 460 assert( pExpr->x.pList==0 ); 461 assert( pExpr->x.pSelect==0 ); 462 pOrig = pEList->a[j].pExpr; 463 if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){ 464 sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs); 465 return WRC_Abort; 466 } 467 if( ExprHasProperty(pOrig, EP_Win) 468 && ((pNC->ncFlags&NC_AllowWin)==0 || pNC!=pTopNC ) 469 ){ 470 sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs); 471 return WRC_Abort; 472 } 473 if( sqlite3ExprVectorSize(pOrig)!=1 ){ 474 sqlite3ErrorMsg(pParse, "row value misused"); 475 return WRC_Abort; 476 } 477 resolveAlias(pParse, pEList, j, pExpr, "", nSubquery); 478 cnt = 1; 479 pMatch = 0; 480 assert( zTab==0 && zDb==0 ); 481 if( IN_RENAME_OBJECT ){ 482 sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr); 483 } 484 goto lookupname_end; 485 } 486 } 487 } 488 489 /* Advance to the next name context. The loop will exit when either 490 ** we have a match (cnt>0) or when we run out of name contexts. 491 */ 492 if( cnt ) break; 493 pNC = pNC->pNext; 494 nSubquery++; 495 }while( pNC ); 496 497 498 /* 499 ** If X and Y are NULL (in other words if only the column name Z is 500 ** supplied) and the value of Z is enclosed in double-quotes, then 501 ** Z is a string literal if it doesn't match any column names. In that 502 ** case, we need to return right away and not make any changes to 503 ** pExpr. 504 ** 505 ** Because no reference was made to outer contexts, the pNC->nRef 506 ** fields are not changed in any context. 507 */ 508 if( cnt==0 && zTab==0 ){ 509 assert( pExpr->op==TK_ID ); 510 if( ExprHasProperty(pExpr,EP_DblQuoted) 511 && areDoubleQuotedStringsEnabled(db, pTopNC) 512 ){ 513 /* If a double-quoted identifier does not match any known column name, 514 ** then treat it as a string. 515 ** 516 ** This hack was added in the early days of SQLite in a misguided attempt 517 ** to be compatible with MySQL 3.x, which used double-quotes for strings. 518 ** I now sorely regret putting in this hack. The effect of this hack is 519 ** that misspelled identifier names are silently converted into strings 520 ** rather than causing an error, to the frustration of countless 521 ** programmers. To all those frustrated programmers, my apologies. 522 ** 523 ** Someday, I hope to get rid of this hack. Unfortunately there is 524 ** a huge amount of legacy SQL that uses it. So for now, we just 525 ** issue a warning. 526 */ 527 sqlite3_log(SQLITE_WARNING, 528 "double-quoted string literal: \"%w\"", zCol); 529 #ifdef SQLITE_ENABLE_NORMALIZE 530 sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol); 531 #endif 532 pExpr->op = TK_STRING; 533 pExpr->y.pTab = 0; 534 return WRC_Prune; 535 } 536 if( sqlite3ExprIdToTrueFalse(pExpr) ){ 537 return WRC_Prune; 538 } 539 } 540 541 /* 542 ** cnt==0 means there was not match. cnt>1 means there were two or 543 ** more matches. Either way, we have an error. 544 */ 545 if( cnt!=1 ){ 546 const char *zErr; 547 zErr = cnt==0 ? "no such column" : "ambiguous column name"; 548 if( zDb ){ 549 sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol); 550 }else if( zTab ){ 551 sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol); 552 }else{ 553 sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol); 554 } 555 pParse->checkSchema = 1; 556 pTopNC->nErr++; 557 } 558 559 /* If a column from a table in pSrcList is referenced, then record 560 ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes 561 ** bit 0 to be set. Column 1 sets bit 1. And so forth. Bit 63 is 562 ** set if the 63rd or any subsequent column is used. 563 ** 564 ** The colUsed mask is an optimization used to help determine if an 565 ** index is a covering index. The correct answer is still obtained 566 ** if the mask contains extra set bits. However, it is important to 567 ** avoid setting bits beyond the maximum column number of the table. 568 ** (See ticket [b92e5e8ec2cdbaa1]). 569 ** 570 ** If a generated column is referenced, set bits for every column 571 ** of the table. 572 */ 573 if( pExpr->iColumn>=0 && pMatch!=0 ){ 574 int n = pExpr->iColumn; 575 Table *pExTab = pExpr->y.pTab; 576 assert( pExTab!=0 ); 577 assert( pMatch->iCursor==pExpr->iTable ); 578 if( (pExTab->tabFlags & TF_HasGenerated)!=0 579 && (pExTab->aCol[n].colFlags & COLFLAG_GENERATED)!=0 580 ){ 581 testcase( pExTab->nCol==BMS-1 ); 582 testcase( pExTab->nCol==BMS ); 583 pMatch->colUsed = pExTab->nCol>=BMS ? ALLBITS : MASKBIT(pExTab->nCol)-1; 584 }else{ 585 testcase( n==BMS-1 ); 586 testcase( n==BMS ); 587 if( n>=BMS ) n = BMS-1; 588 pMatch->colUsed |= ((Bitmask)1)<<n; 589 } 590 } 591 592 /* Clean up and return 593 */ 594 sqlite3ExprDelete(db, pExpr->pLeft); 595 pExpr->pLeft = 0; 596 sqlite3ExprDelete(db, pExpr->pRight); 597 pExpr->pRight = 0; 598 pExpr->op = eNewExprOp; 599 ExprSetProperty(pExpr, EP_Leaf); 600 lookupname_end: 601 if( cnt==1 ){ 602 assert( pNC!=0 ); 603 if( !ExprHasProperty(pExpr, EP_Alias) ){ 604 sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); 605 } 606 /* Increment the nRef value on all name contexts from TopNC up to 607 ** the point where the name matched. */ 608 for(;;){ 609 assert( pTopNC!=0 ); 610 pTopNC->nRef++; 611 if( pTopNC==pNC ) break; 612 pTopNC = pTopNC->pNext; 613 } 614 return WRC_Prune; 615 } else { 616 return WRC_Abort; 617 } 618 } 619 620 /* 621 ** Allocate and return a pointer to an expression to load the column iCol 622 ** from datasource iSrc in SrcList pSrc. 623 */ 624 Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){ 625 Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0); 626 if( p ){ 627 struct SrcList_item *pItem = &pSrc->a[iSrc]; 628 Table *pTab = p->y.pTab = pItem->pTab; 629 p->iTable = pItem->iCursor; 630 if( p->y.pTab->iPKey==iCol ){ 631 p->iColumn = -1; 632 }else{ 633 p->iColumn = (ynVar)iCol; 634 if( (pTab->tabFlags & TF_HasGenerated)!=0 635 && (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0 636 ){ 637 testcase( pTab->nCol==63 ); 638 testcase( pTab->nCol==64 ); 639 pItem->colUsed = pTab->nCol>=64 ? ALLBITS : MASKBIT(pTab->nCol)-1; 640 }else{ 641 testcase( iCol==BMS ); 642 testcase( iCol==BMS-1 ); 643 pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol); 644 } 645 } 646 } 647 return p; 648 } 649 650 /* 651 ** Report an error that an expression is not valid for some set of 652 ** pNC->ncFlags values determined by validMask. 653 ** 654 ** static void notValid( 655 ** Parse *pParse, // Leave error message here 656 ** NameContext *pNC, // The name context 657 ** const char *zMsg, // Type of error 658 ** int validMask, // Set of contexts for which prohibited 659 ** Expr *pExpr // Invalidate this expression on error 660 ** ){...} 661 ** 662 ** As an optimization, since the conditional is almost always false 663 ** (because errors are rare), the conditional is moved outside of the 664 ** function call using a macro. 665 */ 666 static void notValidImpl( 667 Parse *pParse, /* Leave error message here */ 668 NameContext *pNC, /* The name context */ 669 const char *zMsg, /* Type of error */ 670 Expr *pExpr /* Invalidate this expression on error */ 671 ){ 672 const char *zIn = "partial index WHERE clauses"; 673 if( pNC->ncFlags & NC_IdxExpr ) zIn = "index expressions"; 674 #ifndef SQLITE_OMIT_CHECK 675 else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints"; 676 #endif 677 #ifndef SQLITE_OMIT_GENERATED_COLUMNS 678 else if( pNC->ncFlags & NC_GenCol ) zIn = "generated columns"; 679 #endif 680 sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn); 681 if( pExpr ) pExpr->op = TK_NULL; 682 } 683 #define sqlite3ResolveNotValid(P,N,M,X,E) \ 684 assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \ 685 if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E); 686 687 /* 688 ** Expression p should encode a floating point value between 1.0 and 0.0. 689 ** Return 1024 times this value. Or return -1 if p is not a floating point 690 ** value between 1.0 and 0.0. 691 */ 692 static int exprProbability(Expr *p){ 693 double r = -1.0; 694 if( p->op!=TK_FLOAT ) return -1; 695 sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8); 696 assert( r>=0.0 ); 697 if( r>1.0 ) return -1; 698 return (int)(r*134217728.0); 699 } 700 701 /* 702 ** This routine is callback for sqlite3WalkExpr(). 703 ** 704 ** Resolve symbolic names into TK_COLUMN operators for the current 705 ** node in the expression tree. Return 0 to continue the search down 706 ** the tree or 2 to abort the tree walk. 707 ** 708 ** This routine also does error checking and name resolution for 709 ** function names. The operator for aggregate functions is changed 710 ** to TK_AGG_FUNCTION. 711 */ 712 static int resolveExprStep(Walker *pWalker, Expr *pExpr){ 713 NameContext *pNC; 714 Parse *pParse; 715 716 pNC = pWalker->u.pNC; 717 assert( pNC!=0 ); 718 pParse = pNC->pParse; 719 assert( pParse==pWalker->pParse ); 720 721 #ifndef NDEBUG 722 if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ 723 SrcList *pSrcList = pNC->pSrcList; 724 int i; 725 for(i=0; i<pNC->pSrcList->nSrc; i++){ 726 assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); 727 } 728 } 729 #endif 730 switch( pExpr->op ){ 731 732 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) 733 /* The special operator TK_ROW means use the rowid for the first 734 ** column in the FROM clause. This is used by the LIMIT and ORDER BY 735 ** clause processing on UPDATE and DELETE statements. 736 */ 737 case TK_ROW: { 738 SrcList *pSrcList = pNC->pSrcList; 739 struct SrcList_item *pItem; 740 assert( pSrcList && pSrcList->nSrc==1 ); 741 pItem = pSrcList->a; 742 assert( HasRowid(pItem->pTab) && pItem->pTab->pSelect==0 ); 743 pExpr->op = TK_COLUMN; 744 pExpr->y.pTab = pItem->pTab; 745 pExpr->iTable = pItem->iCursor; 746 pExpr->iColumn = -1; 747 pExpr->affExpr = SQLITE_AFF_INTEGER; 748 break; 749 } 750 #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) 751 && !defined(SQLITE_OMIT_SUBQUERY) */ 752 753 /* A column name: ID 754 ** Or table name and column name: ID.ID 755 ** Or a database, table and column: ID.ID.ID 756 ** 757 ** The TK_ID and TK_OUT cases are combined so that there will only 758 ** be one call to lookupName(). Then the compiler will in-line 759 ** lookupName() for a size reduction and performance increase. 760 */ 761 case TK_ID: 762 case TK_DOT: { 763 const char *zColumn; 764 const char *zTable; 765 const char *zDb; 766 Expr *pRight; 767 768 if( pExpr->op==TK_ID ){ 769 zDb = 0; 770 zTable = 0; 771 zColumn = pExpr->u.zToken; 772 }else{ 773 Expr *pLeft = pExpr->pLeft; 774 testcase( pNC->ncFlags & NC_IdxExpr ); 775 testcase( pNC->ncFlags & NC_GenCol ); 776 sqlite3ResolveNotValid(pParse, pNC, "the \".\" operator", 777 NC_IdxExpr|NC_GenCol, 0); 778 pRight = pExpr->pRight; 779 if( pRight->op==TK_ID ){ 780 zDb = 0; 781 }else{ 782 assert( pRight->op==TK_DOT ); 783 zDb = pLeft->u.zToken; 784 pLeft = pRight->pLeft; 785 pRight = pRight->pRight; 786 } 787 zTable = pLeft->u.zToken; 788 zColumn = pRight->u.zToken; 789 if( IN_RENAME_OBJECT ){ 790 sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight); 791 sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft); 792 } 793 } 794 return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr); 795 } 796 797 /* Resolve function names 798 */ 799 case TK_FUNCTION: { 800 ExprList *pList = pExpr->x.pList; /* The argument list */ 801 int n = pList ? pList->nExpr : 0; /* Number of arguments */ 802 int no_such_func = 0; /* True if no such function exists */ 803 int wrong_num_args = 0; /* True if wrong number of arguments */ 804 int is_agg = 0; /* True if is an aggregate function */ 805 int nId; /* Number of characters in function name */ 806 const char *zId; /* The function name. */ 807 FuncDef *pDef; /* Information about the function */ 808 u8 enc = ENC(pParse->db); /* The database encoding */ 809 int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin)); 810 #ifndef SQLITE_OMIT_WINDOWFUNC 811 Window *pWin = (IsWindowFunc(pExpr) ? pExpr->y.pWin : 0); 812 #endif 813 assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); 814 zId = pExpr->u.zToken; 815 nId = sqlite3Strlen30(zId); 816 pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0); 817 if( pDef==0 ){ 818 pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0); 819 if( pDef==0 ){ 820 no_such_func = 1; 821 }else{ 822 wrong_num_args = 1; 823 } 824 }else{ 825 is_agg = pDef->xFinalize!=0; 826 if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){ 827 ExprSetProperty(pExpr, EP_Unlikely); 828 if( n==2 ){ 829 pExpr->iTable = exprProbability(pList->a[1].pExpr); 830 if( pExpr->iTable<0 ){ 831 sqlite3ErrorMsg(pParse, 832 "second argument to likelihood() must be a " 833 "constant between 0.0 and 1.0"); 834 pNC->nErr++; 835 } 836 }else{ 837 /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is 838 ** equivalent to likelihood(X, 0.0625). 839 ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is 840 ** short-hand for likelihood(X,0.0625). 841 ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand 842 ** for likelihood(X,0.9375). 843 ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent 844 ** to likelihood(X,0.9375). */ 845 /* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */ 846 pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120; 847 } 848 } 849 #ifndef SQLITE_OMIT_AUTHORIZATION 850 { 851 int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0); 852 if( auth!=SQLITE_OK ){ 853 if( auth==SQLITE_DENY ){ 854 sqlite3ErrorMsg(pParse, "not authorized to use function: %s", 855 pDef->zName); 856 pNC->nErr++; 857 } 858 pExpr->op = TK_NULL; 859 return WRC_Prune; 860 } 861 } 862 #endif 863 if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){ 864 /* For the purposes of the EP_ConstFunc flag, date and time 865 ** functions and other functions that change slowly are considered 866 ** constant because they are constant for the duration of one query. 867 ** This allows them to be factored out of inner loops. */ 868 ExprSetProperty(pExpr,EP_ConstFunc); 869 } 870 if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){ 871 /* Date/time functions that use 'now', and other functions like 872 ** sqlite_version() that might change over time cannot be used 873 ** in an index. */ 874 sqlite3ResolveNotValid(pParse, pNC, "non-deterministic functions", 875 NC_SelfRef, 0); 876 }else{ 877 assert( (NC_SelfRef & 0xff)==NC_SelfRef ); /* Must fit in 8 bits */ 878 pExpr->op2 = pNC->ncFlags & NC_SelfRef; 879 if( pNC->ncFlags & NC_FromDDL ) ExprSetProperty(pExpr, EP_FromDDL); 880 } 881 if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0 882 && pParse->nested==0 883 && (pParse->db->mDbFlags & DBFLAG_InternalFunc)==0 884 ){ 885 /* Internal-use-only functions are disallowed unless the 886 ** SQL is being compiled using sqlite3NestedParse() or 887 ** the SQLITE_TESTCTRL_INTERNAL_FUNCTIONS test-control has be 888 ** used to activate internal functionsn for testing purposes */ 889 no_such_func = 1; 890 pDef = 0; 891 }else 892 if( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 893 && !IN_RENAME_OBJECT 894 ){ 895 sqlite3ExprFunctionUsable(pParse, pExpr, pDef); 896 } 897 } 898 899 if( 0==IN_RENAME_OBJECT ){ 900 #ifndef SQLITE_OMIT_WINDOWFUNC 901 assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX) 902 || (pDef->xValue==0 && pDef->xInverse==0) 903 || (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize) 904 ); 905 if( pDef && pDef->xValue==0 && pWin ){ 906 sqlite3ErrorMsg(pParse, 907 "%.*s() may not be used as a window function", nId, zId 908 ); 909 pNC->nErr++; 910 }else if( 911 (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) 912 || (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pWin) 913 || (is_agg && pWin && (pNC->ncFlags & NC_AllowWin)==0) 914 ){ 915 const char *zType; 916 if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pWin ){ 917 zType = "window"; 918 }else{ 919 zType = "aggregate"; 920 } 921 sqlite3ErrorMsg(pParse, "misuse of %s function %.*s()",zType,nId,zId); 922 pNC->nErr++; 923 is_agg = 0; 924 } 925 #else 926 if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){ 927 sqlite3ErrorMsg(pParse,"misuse of aggregate function %.*s()",nId,zId); 928 pNC->nErr++; 929 is_agg = 0; 930 } 931 #endif 932 else if( no_such_func && pParse->db->init.busy==0 933 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION 934 && pParse->explain==0 935 #endif 936 ){ 937 sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); 938 pNC->nErr++; 939 }else if( wrong_num_args ){ 940 sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", 941 nId, zId); 942 pNC->nErr++; 943 } 944 #ifndef SQLITE_OMIT_WINDOWFUNC 945 else if( is_agg==0 && ExprHasProperty(pExpr, EP_WinFunc) ){ 946 sqlite3ErrorMsg(pParse, 947 "FILTER may not be used with non-aggregate %.*s()", 948 nId, zId 949 ); 950 pNC->nErr++; 951 } 952 #endif 953 if( is_agg ){ 954 /* Window functions may not be arguments of aggregate functions. 955 ** Or arguments of other window functions. But aggregate functions 956 ** may be arguments for window functions. */ 957 #ifndef SQLITE_OMIT_WINDOWFUNC 958 pNC->ncFlags &= ~(NC_AllowWin | (!pWin ? NC_AllowAgg : 0)); 959 #else 960 pNC->ncFlags &= ~NC_AllowAgg; 961 #endif 962 } 963 } 964 #ifndef SQLITE_OMIT_WINDOWFUNC 965 else if( ExprHasProperty(pExpr, EP_WinFunc) ){ 966 is_agg = 1; 967 } 968 #endif 969 sqlite3WalkExprList(pWalker, pList); 970 if( is_agg ){ 971 #ifndef SQLITE_OMIT_WINDOWFUNC 972 if( pWin ){ 973 Select *pSel = pNC->pWinSelect; 974 assert( pWin==pExpr->y.pWin ); 975 if( IN_RENAME_OBJECT==0 ){ 976 sqlite3WindowUpdate(pParse, pSel ? pSel->pWinDefn : 0, pWin, pDef); 977 } 978 sqlite3WalkExprList(pWalker, pWin->pPartition); 979 sqlite3WalkExprList(pWalker, pWin->pOrderBy); 980 sqlite3WalkExpr(pWalker, pWin->pFilter); 981 sqlite3WindowLink(pSel, pWin); 982 pNC->ncFlags |= NC_HasWin; 983 }else 984 #endif /* SQLITE_OMIT_WINDOWFUNC */ 985 { 986 NameContext *pNC2 = pNC; 987 pExpr->op = TK_AGG_FUNCTION; 988 pExpr->op2 = 0; 989 #ifndef SQLITE_OMIT_WINDOWFUNC 990 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 991 sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter); 992 } 993 #endif 994 while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){ 995 pExpr->op2++; 996 pNC2 = pNC2->pNext; 997 } 998 assert( pDef!=0 || IN_RENAME_OBJECT ); 999 if( pNC2 && pDef ){ 1000 assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg ); 1001 testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 ); 1002 pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX); 1003 1004 } 1005 } 1006 pNC->ncFlags |= savedAllowFlags; 1007 } 1008 /* FIX ME: Compute pExpr->affinity based on the expected return 1009 ** type of the function 1010 */ 1011 return WRC_Prune; 1012 } 1013 #ifndef SQLITE_OMIT_SUBQUERY 1014 case TK_SELECT: 1015 case TK_EXISTS: testcase( pExpr->op==TK_EXISTS ); 1016 #endif 1017 case TK_IN: { 1018 testcase( pExpr->op==TK_IN ); 1019 if( ExprHasProperty(pExpr, EP_xIsSelect) ){ 1020 int nRef = pNC->nRef; 1021 testcase( pNC->ncFlags & NC_IsCheck ); 1022 testcase( pNC->ncFlags & NC_PartIdx ); 1023 testcase( pNC->ncFlags & NC_IdxExpr ); 1024 testcase( pNC->ncFlags & NC_GenCol ); 1025 sqlite3ResolveNotValid(pParse, pNC, "subqueries", 1026 NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol, pExpr); 1027 sqlite3WalkSelect(pWalker, pExpr->x.pSelect); 1028 assert( pNC->nRef>=nRef ); 1029 if( nRef!=pNC->nRef ){ 1030 ExprSetProperty(pExpr, EP_VarSelect); 1031 pNC->ncFlags |= NC_VarSelect; 1032 } 1033 } 1034 break; 1035 } 1036 case TK_VARIABLE: { 1037 testcase( pNC->ncFlags & NC_IsCheck ); 1038 testcase( pNC->ncFlags & NC_PartIdx ); 1039 testcase( pNC->ncFlags & NC_IdxExpr ); 1040 testcase( pNC->ncFlags & NC_GenCol ); 1041 sqlite3ResolveNotValid(pParse, pNC, "parameters", 1042 NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol, pExpr); 1043 break; 1044 } 1045 case TK_IS: 1046 case TK_ISNOT: { 1047 Expr *pRight = sqlite3ExprSkipCollateAndLikely(pExpr->pRight); 1048 assert( !ExprHasProperty(pExpr, EP_Reduced) ); 1049 /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE", 1050 ** and "x IS NOT FALSE". */ 1051 if( pRight->op==TK_ID ){ 1052 int rc = resolveExprStep(pWalker, pRight); 1053 if( rc==WRC_Abort ) return WRC_Abort; 1054 if( pRight->op==TK_TRUEFALSE ){ 1055 pExpr->op2 = pExpr->op; 1056 pExpr->op = TK_TRUTH; 1057 return WRC_Continue; 1058 } 1059 } 1060 /* Fall thru */ 1061 } 1062 case TK_BETWEEN: 1063 case TK_EQ: 1064 case TK_NE: 1065 case TK_LT: 1066 case TK_LE: 1067 case TK_GT: 1068 case TK_GE: { 1069 int nLeft, nRight; 1070 if( pParse->db->mallocFailed ) break; 1071 assert( pExpr->pLeft!=0 ); 1072 nLeft = sqlite3ExprVectorSize(pExpr->pLeft); 1073 if( pExpr->op==TK_BETWEEN ){ 1074 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr); 1075 if( nRight==nLeft ){ 1076 nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr); 1077 } 1078 }else{ 1079 assert( pExpr->pRight!=0 ); 1080 nRight = sqlite3ExprVectorSize(pExpr->pRight); 1081 } 1082 if( nLeft!=nRight ){ 1083 testcase( pExpr->op==TK_EQ ); 1084 testcase( pExpr->op==TK_NE ); 1085 testcase( pExpr->op==TK_LT ); 1086 testcase( pExpr->op==TK_LE ); 1087 testcase( pExpr->op==TK_GT ); 1088 testcase( pExpr->op==TK_GE ); 1089 testcase( pExpr->op==TK_IS ); 1090 testcase( pExpr->op==TK_ISNOT ); 1091 testcase( pExpr->op==TK_BETWEEN ); 1092 sqlite3ErrorMsg(pParse, "row value misused"); 1093 } 1094 break; 1095 } 1096 } 1097 return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue; 1098 } 1099 1100 /* 1101 ** pEList is a list of expressions which are really the result set of the 1102 ** a SELECT statement. pE is a term in an ORDER BY or GROUP BY clause. 1103 ** This routine checks to see if pE is a simple identifier which corresponds 1104 ** to the AS-name of one of the terms of the expression list. If it is, 1105 ** this routine return an integer between 1 and N where N is the number of 1106 ** elements in pEList, corresponding to the matching entry. If there is 1107 ** no match, or if pE is not a simple identifier, then this routine 1108 ** return 0. 1109 ** 1110 ** pEList has been resolved. pE has not. 1111 */ 1112 static int resolveAsName( 1113 Parse *pParse, /* Parsing context for error messages */ 1114 ExprList *pEList, /* List of expressions to scan */ 1115 Expr *pE /* Expression we are trying to match */ 1116 ){ 1117 int i; /* Loop counter */ 1118 1119 UNUSED_PARAMETER(pParse); 1120 1121 if( pE->op==TK_ID ){ 1122 char *zCol = pE->u.zToken; 1123 for(i=0; i<pEList->nExpr; i++){ 1124 if( pEList->a[i].eEName==ENAME_NAME 1125 && sqlite3_stricmp(pEList->a[i].zEName, zCol)==0 1126 ){ 1127 return i+1; 1128 } 1129 } 1130 } 1131 return 0; 1132 } 1133 1134 /* 1135 ** pE is a pointer to an expression which is a single term in the 1136 ** ORDER BY of a compound SELECT. The expression has not been 1137 ** name resolved. 1138 ** 1139 ** At the point this routine is called, we already know that the 1140 ** ORDER BY term is not an integer index into the result set. That 1141 ** case is handled by the calling routine. 1142 ** 1143 ** Attempt to match pE against result set columns in the left-most 1144 ** SELECT statement. Return the index i of the matching column, 1145 ** as an indication to the caller that it should sort by the i-th column. 1146 ** The left-most column is 1. In other words, the value returned is the 1147 ** same integer value that would be used in the SQL statement to indicate 1148 ** the column. 1149 ** 1150 ** If there is no match, return 0. Return -1 if an error occurs. 1151 */ 1152 static int resolveOrderByTermToExprList( 1153 Parse *pParse, /* Parsing context for error messages */ 1154 Select *pSelect, /* The SELECT statement with the ORDER BY clause */ 1155 Expr *pE /* The specific ORDER BY term */ 1156 ){ 1157 int i; /* Loop counter */ 1158 ExprList *pEList; /* The columns of the result set */ 1159 NameContext nc; /* Name context for resolving pE */ 1160 sqlite3 *db; /* Database connection */ 1161 int rc; /* Return code from subprocedures */ 1162 u8 savedSuppErr; /* Saved value of db->suppressErr */ 1163 1164 assert( sqlite3ExprIsInteger(pE, &i)==0 ); 1165 pEList = pSelect->pEList; 1166 1167 /* Resolve all names in the ORDER BY term expression 1168 */ 1169 memset(&nc, 0, sizeof(nc)); 1170 nc.pParse = pParse; 1171 nc.pSrcList = pSelect->pSrc; 1172 nc.uNC.pEList = pEList; 1173 nc.ncFlags = NC_AllowAgg|NC_UEList; 1174 nc.nErr = 0; 1175 db = pParse->db; 1176 savedSuppErr = db->suppressErr; 1177 db->suppressErr = 1; 1178 rc = sqlite3ResolveExprNames(&nc, pE); 1179 db->suppressErr = savedSuppErr; 1180 if( rc ) return 0; 1181 1182 /* Try to match the ORDER BY expression against an expression 1183 ** in the result set. Return an 1-based index of the matching 1184 ** result-set entry. 1185 */ 1186 for(i=0; i<pEList->nExpr; i++){ 1187 if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){ 1188 return i+1; 1189 } 1190 } 1191 1192 /* If no match, return 0. */ 1193 return 0; 1194 } 1195 1196 /* 1197 ** Generate an ORDER BY or GROUP BY term out-of-range error. 1198 */ 1199 static void resolveOutOfRangeError( 1200 Parse *pParse, /* The error context into which to write the error */ 1201 const char *zType, /* "ORDER" or "GROUP" */ 1202 int i, /* The index (1-based) of the term out of range */ 1203 int mx /* Largest permissible value of i */ 1204 ){ 1205 sqlite3ErrorMsg(pParse, 1206 "%r %s BY term out of range - should be " 1207 "between 1 and %d", i, zType, mx); 1208 } 1209 1210 /* 1211 ** Analyze the ORDER BY clause in a compound SELECT statement. Modify 1212 ** each term of the ORDER BY clause is a constant integer between 1 1213 ** and N where N is the number of columns in the compound SELECT. 1214 ** 1215 ** ORDER BY terms that are already an integer between 1 and N are 1216 ** unmodified. ORDER BY terms that are integers outside the range of 1217 ** 1 through N generate an error. ORDER BY terms that are expressions 1218 ** are matched against result set expressions of compound SELECT 1219 ** beginning with the left-most SELECT and working toward the right. 1220 ** At the first match, the ORDER BY expression is transformed into 1221 ** the integer column number. 1222 ** 1223 ** Return the number of errors seen. 1224 */ 1225 static int resolveCompoundOrderBy( 1226 Parse *pParse, /* Parsing context. Leave error messages here */ 1227 Select *pSelect /* The SELECT statement containing the ORDER BY */ 1228 ){ 1229 int i; 1230 ExprList *pOrderBy; 1231 ExprList *pEList; 1232 sqlite3 *db; 1233 int moreToDo = 1; 1234 1235 pOrderBy = pSelect->pOrderBy; 1236 if( pOrderBy==0 ) return 0; 1237 db = pParse->db; 1238 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1239 sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause"); 1240 return 1; 1241 } 1242 for(i=0; i<pOrderBy->nExpr; i++){ 1243 pOrderBy->a[i].done = 0; 1244 } 1245 pSelect->pNext = 0; 1246 while( pSelect->pPrior ){ 1247 pSelect->pPrior->pNext = pSelect; 1248 pSelect = pSelect->pPrior; 1249 } 1250 while( pSelect && moreToDo ){ 1251 struct ExprList_item *pItem; 1252 moreToDo = 0; 1253 pEList = pSelect->pEList; 1254 assert( pEList!=0 ); 1255 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1256 int iCol = -1; 1257 Expr *pE, *pDup; 1258 if( pItem->done ) continue; 1259 pE = sqlite3ExprSkipCollateAndLikely(pItem->pExpr); 1260 if( sqlite3ExprIsInteger(pE, &iCol) ){ 1261 if( iCol<=0 || iCol>pEList->nExpr ){ 1262 resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr); 1263 return 1; 1264 } 1265 }else{ 1266 iCol = resolveAsName(pParse, pEList, pE); 1267 if( iCol==0 ){ 1268 /* Now test if expression pE matches one of the values returned 1269 ** by pSelect. In the usual case this is done by duplicating the 1270 ** expression, resolving any symbols in it, and then comparing 1271 ** it against each expression returned by the SELECT statement. 1272 ** Once the comparisons are finished, the duplicate expression 1273 ** is deleted. 1274 ** 1275 ** Or, if this is running as part of an ALTER TABLE operation, 1276 ** resolve the symbols in the actual expression, not a duplicate. 1277 ** And, if one of the comparisons is successful, leave the expression 1278 ** as is instead of transforming it to an integer as in the usual 1279 ** case. This allows the code in alter.c to modify column 1280 ** refererences within the ORDER BY expression as required. */ 1281 if( IN_RENAME_OBJECT ){ 1282 pDup = pE; 1283 }else{ 1284 pDup = sqlite3ExprDup(db, pE, 0); 1285 } 1286 if( !db->mallocFailed ){ 1287 assert(pDup); 1288 iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup); 1289 } 1290 if( !IN_RENAME_OBJECT ){ 1291 sqlite3ExprDelete(db, pDup); 1292 } 1293 } 1294 } 1295 if( iCol>0 ){ 1296 /* Convert the ORDER BY term into an integer column number iCol, 1297 ** taking care to preserve the COLLATE clause if it exists */ 1298 if( !IN_RENAME_OBJECT ){ 1299 Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); 1300 if( pNew==0 ) return 1; 1301 pNew->flags |= EP_IntValue; 1302 pNew->u.iValue = iCol; 1303 if( pItem->pExpr==pE ){ 1304 pItem->pExpr = pNew; 1305 }else{ 1306 Expr *pParent = pItem->pExpr; 1307 assert( pParent->op==TK_COLLATE ); 1308 while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft; 1309 assert( pParent->pLeft==pE ); 1310 pParent->pLeft = pNew; 1311 } 1312 sqlite3ExprDelete(db, pE); 1313 pItem->u.x.iOrderByCol = (u16)iCol; 1314 } 1315 pItem->done = 1; 1316 }else{ 1317 moreToDo = 1; 1318 } 1319 } 1320 pSelect = pSelect->pNext; 1321 } 1322 for(i=0; i<pOrderBy->nExpr; i++){ 1323 if( pOrderBy->a[i].done==0 ){ 1324 sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any " 1325 "column in the result set", i+1); 1326 return 1; 1327 } 1328 } 1329 return 0; 1330 } 1331 1332 /* 1333 ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of 1334 ** the SELECT statement pSelect. If any term is reference to a 1335 ** result set expression (as determined by the ExprList.a.u.x.iOrderByCol 1336 ** field) then convert that term into a copy of the corresponding result set 1337 ** column. 1338 ** 1339 ** If any errors are detected, add an error message to pParse and 1340 ** return non-zero. Return zero if no errors are seen. 1341 */ 1342 int sqlite3ResolveOrderGroupBy( 1343 Parse *pParse, /* Parsing context. Leave error messages here */ 1344 Select *pSelect, /* The SELECT statement containing the clause */ 1345 ExprList *pOrderBy, /* The ORDER BY or GROUP BY clause to be processed */ 1346 const char *zType /* "ORDER" or "GROUP" */ 1347 ){ 1348 int i; 1349 sqlite3 *db = pParse->db; 1350 ExprList *pEList; 1351 struct ExprList_item *pItem; 1352 1353 if( pOrderBy==0 || pParse->db->mallocFailed || IN_RENAME_OBJECT ) return 0; 1354 if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ 1355 sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType); 1356 return 1; 1357 } 1358 pEList = pSelect->pEList; 1359 assert( pEList!=0 ); /* sqlite3SelectNew() guarantees this */ 1360 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1361 if( pItem->u.x.iOrderByCol ){ 1362 if( pItem->u.x.iOrderByCol>pEList->nExpr ){ 1363 resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr); 1364 return 1; 1365 } 1366 resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr, 1367 zType,0); 1368 } 1369 } 1370 return 0; 1371 } 1372 1373 #ifndef SQLITE_OMIT_WINDOWFUNC 1374 /* 1375 ** Walker callback for windowRemoveExprFromSelect(). 1376 */ 1377 static int resolveRemoveWindowsCb(Walker *pWalker, Expr *pExpr){ 1378 UNUSED_PARAMETER(pWalker); 1379 if( ExprHasProperty(pExpr, EP_WinFunc) ){ 1380 Window *pWin = pExpr->y.pWin; 1381 sqlite3WindowUnlinkFromSelect(pWin); 1382 } 1383 return WRC_Continue; 1384 } 1385 1386 /* 1387 ** Remove any Window objects owned by the expression pExpr from the 1388 ** Select.pWin list of Select object pSelect. 1389 */ 1390 static void windowRemoveExprFromSelect(Select *pSelect, Expr *pExpr){ 1391 if( pSelect->pWin ){ 1392 Walker sWalker; 1393 memset(&sWalker, 0, sizeof(Walker)); 1394 sWalker.xExprCallback = resolveRemoveWindowsCb; 1395 sWalker.u.pSelect = pSelect; 1396 sqlite3WalkExpr(&sWalker, pExpr); 1397 } 1398 } 1399 #else 1400 # define windowRemoveExprFromSelect(a, b) 1401 #endif /* SQLITE_OMIT_WINDOWFUNC */ 1402 1403 /* 1404 ** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect. 1405 ** The Name context of the SELECT statement is pNC. zType is either 1406 ** "ORDER" or "GROUP" depending on which type of clause pOrderBy is. 1407 ** 1408 ** This routine resolves each term of the clause into an expression. 1409 ** If the order-by term is an integer I between 1 and N (where N is the 1410 ** number of columns in the result set of the SELECT) then the expression 1411 ** in the resolution is a copy of the I-th result-set expression. If 1412 ** the order-by term is an identifier that corresponds to the AS-name of 1413 ** a result-set expression, then the term resolves to a copy of the 1414 ** result-set expression. Otherwise, the expression is resolved in 1415 ** the usual way - using sqlite3ResolveExprNames(). 1416 ** 1417 ** This routine returns the number of errors. If errors occur, then 1418 ** an appropriate error message might be left in pParse. (OOM errors 1419 ** excepted.) 1420 */ 1421 static int resolveOrderGroupBy( 1422 NameContext *pNC, /* The name context of the SELECT statement */ 1423 Select *pSelect, /* The SELECT statement holding pOrderBy */ 1424 ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */ 1425 const char *zType /* Either "ORDER" or "GROUP", as appropriate */ 1426 ){ 1427 int i, j; /* Loop counters */ 1428 int iCol; /* Column number */ 1429 struct ExprList_item *pItem; /* A term of the ORDER BY clause */ 1430 Parse *pParse; /* Parsing context */ 1431 int nResult; /* Number of terms in the result set */ 1432 1433 if( pOrderBy==0 ) return 0; 1434 nResult = pSelect->pEList->nExpr; 1435 pParse = pNC->pParse; 1436 for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ 1437 Expr *pE = pItem->pExpr; 1438 Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pE); 1439 if( zType[0]!='G' ){ 1440 iCol = resolveAsName(pParse, pSelect->pEList, pE2); 1441 if( iCol>0 ){ 1442 /* If an AS-name match is found, mark this ORDER BY column as being 1443 ** a copy of the iCol-th result-set column. The subsequent call to 1444 ** sqlite3ResolveOrderGroupBy() will convert the expression to a 1445 ** copy of the iCol-th result-set expression. */ 1446 pItem->u.x.iOrderByCol = (u16)iCol; 1447 continue; 1448 } 1449 } 1450 if( sqlite3ExprIsInteger(pE2, &iCol) ){ 1451 /* The ORDER BY term is an integer constant. Again, set the column 1452 ** number so that sqlite3ResolveOrderGroupBy() will convert the 1453 ** order-by term to a copy of the result-set expression */ 1454 if( iCol<1 || iCol>0xffff ){ 1455 resolveOutOfRangeError(pParse, zType, i+1, nResult); 1456 return 1; 1457 } 1458 pItem->u.x.iOrderByCol = (u16)iCol; 1459 continue; 1460 } 1461 1462 /* Otherwise, treat the ORDER BY term as an ordinary expression */ 1463 pItem->u.x.iOrderByCol = 0; 1464 if( sqlite3ResolveExprNames(pNC, pE) ){ 1465 return 1; 1466 } 1467 for(j=0; j<pSelect->pEList->nExpr; j++){ 1468 if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){ 1469 /* Since this expresion is being changed into a reference 1470 ** to an identical expression in the result set, remove all Window 1471 ** objects belonging to the expression from the Select.pWin list. */ 1472 windowRemoveExprFromSelect(pSelect, pE); 1473 pItem->u.x.iOrderByCol = j+1; 1474 } 1475 } 1476 } 1477 return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType); 1478 } 1479 1480 /* 1481 ** Resolve names in the SELECT statement p and all of its descendants. 1482 */ 1483 static int resolveSelectStep(Walker *pWalker, Select *p){ 1484 NameContext *pOuterNC; /* Context that contains this SELECT */ 1485 NameContext sNC; /* Name context of this SELECT */ 1486 int isCompound; /* True if p is a compound select */ 1487 int nCompound; /* Number of compound terms processed so far */ 1488 Parse *pParse; /* Parsing context */ 1489 int i; /* Loop counter */ 1490 ExprList *pGroupBy; /* The GROUP BY clause */ 1491 Select *pLeftmost; /* Left-most of SELECT of a compound */ 1492 sqlite3 *db; /* Database connection */ 1493 1494 1495 assert( p!=0 ); 1496 if( p->selFlags & SF_Resolved ){ 1497 return WRC_Prune; 1498 } 1499 pOuterNC = pWalker->u.pNC; 1500 pParse = pWalker->pParse; 1501 db = pParse->db; 1502 1503 /* Normally sqlite3SelectExpand() will be called first and will have 1504 ** already expanded this SELECT. However, if this is a subquery within 1505 ** an expression, sqlite3ResolveExprNames() will be called without a 1506 ** prior call to sqlite3SelectExpand(). When that happens, let 1507 ** sqlite3SelectPrep() do all of the processing for this SELECT. 1508 ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and 1509 ** this routine in the correct order. 1510 */ 1511 if( (p->selFlags & SF_Expanded)==0 ){ 1512 sqlite3SelectPrep(pParse, p, pOuterNC); 1513 return (pParse->nErr || db->mallocFailed) ? WRC_Abort : WRC_Prune; 1514 } 1515 1516 isCompound = p->pPrior!=0; 1517 nCompound = 0; 1518 pLeftmost = p; 1519 while( p ){ 1520 assert( (p->selFlags & SF_Expanded)!=0 ); 1521 assert( (p->selFlags & SF_Resolved)==0 ); 1522 p->selFlags |= SF_Resolved; 1523 1524 /* Resolve the expressions in the LIMIT and OFFSET clauses. These 1525 ** are not allowed to refer to any names, so pass an empty NameContext. 1526 */ 1527 memset(&sNC, 0, sizeof(sNC)); 1528 sNC.pParse = pParse; 1529 sNC.pWinSelect = p; 1530 if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){ 1531 return WRC_Abort; 1532 } 1533 1534 /* If the SF_Converted flags is set, then this Select object was 1535 ** was created by the convertCompoundSelectToSubquery() function. 1536 ** In this case the ORDER BY clause (p->pOrderBy) should be resolved 1537 ** as if it were part of the sub-query, not the parent. This block 1538 ** moves the pOrderBy down to the sub-query. It will be moved back 1539 ** after the names have been resolved. */ 1540 if( p->selFlags & SF_Converted ){ 1541 Select *pSub = p->pSrc->a[0].pSelect; 1542 assert( p->pSrc->nSrc==1 && p->pOrderBy ); 1543 assert( pSub->pPrior && pSub->pOrderBy==0 ); 1544 pSub->pOrderBy = p->pOrderBy; 1545 p->pOrderBy = 0; 1546 } 1547 1548 /* Recursively resolve names in all subqueries 1549 */ 1550 for(i=0; i<p->pSrc->nSrc; i++){ 1551 struct SrcList_item *pItem = &p->pSrc->a[i]; 1552 if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){ 1553 NameContext *pNC; /* Used to iterate name contexts */ 1554 int nRef = 0; /* Refcount for pOuterNC and outer contexts */ 1555 const char *zSavedContext = pParse->zAuthContext; 1556 1557 /* Count the total number of references to pOuterNC and all of its 1558 ** parent contexts. After resolving references to expressions in 1559 ** pItem->pSelect, check if this value has changed. If so, then 1560 ** SELECT statement pItem->pSelect must be correlated. Set the 1561 ** pItem->fg.isCorrelated flag if this is the case. */ 1562 for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef; 1563 1564 if( pItem->zName ) pParse->zAuthContext = pItem->zName; 1565 sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC); 1566 pParse->zAuthContext = zSavedContext; 1567 if( pParse->nErr || db->mallocFailed ) return WRC_Abort; 1568 1569 for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef; 1570 assert( pItem->fg.isCorrelated==0 && nRef<=0 ); 1571 pItem->fg.isCorrelated = (nRef!=0); 1572 } 1573 } 1574 1575 /* Set up the local name-context to pass to sqlite3ResolveExprNames() to 1576 ** resolve the result-set expression list. 1577 */ 1578 sNC.ncFlags = NC_AllowAgg|NC_AllowWin; 1579 sNC.pSrcList = p->pSrc; 1580 sNC.pNext = pOuterNC; 1581 1582 /* Resolve names in the result set. */ 1583 if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort; 1584 sNC.ncFlags &= ~NC_AllowWin; 1585 1586 /* If there are no aggregate functions in the result-set, and no GROUP BY 1587 ** expression, do not allow aggregates in any of the other expressions. 1588 */ 1589 assert( (p->selFlags & SF_Aggregate)==0 ); 1590 pGroupBy = p->pGroupBy; 1591 if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){ 1592 assert( NC_MinMaxAgg==SF_MinMaxAgg ); 1593 p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg); 1594 }else{ 1595 sNC.ncFlags &= ~NC_AllowAgg; 1596 } 1597 1598 /* If a HAVING clause is present, then there must be a GROUP BY clause. 1599 */ 1600 if( p->pHaving && !pGroupBy ){ 1601 sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING"); 1602 return WRC_Abort; 1603 } 1604 1605 /* Add the output column list to the name-context before parsing the 1606 ** other expressions in the SELECT statement. This is so that 1607 ** expressions in the WHERE clause (etc.) can refer to expressions by 1608 ** aliases in the result set. 1609 ** 1610 ** Minor point: If this is the case, then the expression will be 1611 ** re-evaluated for each reference to it. 1612 */ 1613 assert( (sNC.ncFlags & (NC_UAggInfo|NC_UUpsert))==0 ); 1614 sNC.uNC.pEList = p->pEList; 1615 sNC.ncFlags |= NC_UEList; 1616 if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort; 1617 if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort; 1618 1619 /* Resolve names in table-valued-function arguments */ 1620 for(i=0; i<p->pSrc->nSrc; i++){ 1621 struct SrcList_item *pItem = &p->pSrc->a[i]; 1622 if( pItem->fg.isTabFunc 1623 && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 1624 ){ 1625 return WRC_Abort; 1626 } 1627 } 1628 1629 /* The ORDER BY and GROUP BY clauses may not refer to terms in 1630 ** outer queries 1631 */ 1632 sNC.pNext = 0; 1633 sNC.ncFlags |= NC_AllowAgg|NC_AllowWin; 1634 1635 /* If this is a converted compound query, move the ORDER BY clause from 1636 ** the sub-query back to the parent query. At this point each term 1637 ** within the ORDER BY clause has been transformed to an integer value. 1638 ** These integers will be replaced by copies of the corresponding result 1639 ** set expressions by the call to resolveOrderGroupBy() below. */ 1640 if( p->selFlags & SF_Converted ){ 1641 Select *pSub = p->pSrc->a[0].pSelect; 1642 p->pOrderBy = pSub->pOrderBy; 1643 pSub->pOrderBy = 0; 1644 } 1645 1646 /* Process the ORDER BY clause for singleton SELECT statements. 1647 ** The ORDER BY clause for compounds SELECT statements is handled 1648 ** below, after all of the result-sets for all of the elements of 1649 ** the compound have been resolved. 1650 ** 1651 ** If there is an ORDER BY clause on a term of a compound-select other 1652 ** than the right-most term, then that is a syntax error. But the error 1653 ** is not detected until much later, and so we need to go ahead and 1654 ** resolve those symbols on the incorrect ORDER BY for consistency. 1655 */ 1656 if( isCompound<=nCompound /* Defer right-most ORDER BY of a compound */ 1657 && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") 1658 ){ 1659 return WRC_Abort; 1660 } 1661 if( db->mallocFailed ){ 1662 return WRC_Abort; 1663 } 1664 sNC.ncFlags &= ~NC_AllowWin; 1665 1666 /* Resolve the GROUP BY clause. At the same time, make sure 1667 ** the GROUP BY clause does not contain aggregate functions. 1668 */ 1669 if( pGroupBy ){ 1670 struct ExprList_item *pItem; 1671 1672 if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){ 1673 return WRC_Abort; 1674 } 1675 for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){ 1676 if( ExprHasProperty(pItem->pExpr, EP_Agg) ){ 1677 sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in " 1678 "the GROUP BY clause"); 1679 return WRC_Abort; 1680 } 1681 } 1682 } 1683 1684 #ifndef SQLITE_OMIT_WINDOWFUNC 1685 if( IN_RENAME_OBJECT ){ 1686 Window *pWin; 1687 for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){ 1688 if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy) 1689 || sqlite3ResolveExprListNames(&sNC, pWin->pPartition) 1690 ){ 1691 return WRC_Abort; 1692 } 1693 } 1694 } 1695 #endif 1696 1697 /* If this is part of a compound SELECT, check that it has the right 1698 ** number of expressions in the select list. */ 1699 if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){ 1700 sqlite3SelectWrongNumTermsError(pParse, p->pNext); 1701 return WRC_Abort; 1702 } 1703 1704 /* Advance to the next term of the compound 1705 */ 1706 p = p->pPrior; 1707 nCompound++; 1708 } 1709 1710 /* Resolve the ORDER BY on a compound SELECT after all terms of 1711 ** the compound have been resolved. 1712 */ 1713 if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){ 1714 return WRC_Abort; 1715 } 1716 1717 return WRC_Prune; 1718 } 1719 1720 /* 1721 ** This routine walks an expression tree and resolves references to 1722 ** table columns and result-set columns. At the same time, do error 1723 ** checking on function usage and set a flag if any aggregate functions 1724 ** are seen. 1725 ** 1726 ** To resolve table columns references we look for nodes (or subtrees) of the 1727 ** form X.Y.Z or Y.Z or just Z where 1728 ** 1729 ** X: The name of a database. Ex: "main" or "temp" or 1730 ** the symbolic name assigned to an ATTACH-ed database. 1731 ** 1732 ** Y: The name of a table in a FROM clause. Or in a trigger 1733 ** one of the special names "old" or "new". 1734 ** 1735 ** Z: The name of a column in table Y. 1736 ** 1737 ** The node at the root of the subtree is modified as follows: 1738 ** 1739 ** Expr.op Changed to TK_COLUMN 1740 ** Expr.pTab Points to the Table object for X.Y 1741 ** Expr.iColumn The column index in X.Y. -1 for the rowid. 1742 ** Expr.iTable The VDBE cursor number for X.Y 1743 ** 1744 ** 1745 ** To resolve result-set references, look for expression nodes of the 1746 ** form Z (with no X and Y prefix) where the Z matches the right-hand 1747 ** size of an AS clause in the result-set of a SELECT. The Z expression 1748 ** is replaced by a copy of the left-hand side of the result-set expression. 1749 ** Table-name and function resolution occurs on the substituted expression 1750 ** tree. For example, in: 1751 ** 1752 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x; 1753 ** 1754 ** The "x" term of the order by is replaced by "a+b" to render: 1755 ** 1756 ** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b; 1757 ** 1758 ** Function calls are checked to make sure that the function is 1759 ** defined and that the correct number of arguments are specified. 1760 ** If the function is an aggregate function, then the NC_HasAgg flag is 1761 ** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION. 1762 ** If an expression contains aggregate functions then the EP_Agg 1763 ** property on the expression is set. 1764 ** 1765 ** An error message is left in pParse if anything is amiss. The number 1766 ** if errors is returned. 1767 */ 1768 int sqlite3ResolveExprNames( 1769 NameContext *pNC, /* Namespace to resolve expressions in. */ 1770 Expr *pExpr /* The expression to be analyzed. */ 1771 ){ 1772 int savedHasAgg; 1773 Walker w; 1774 1775 if( pExpr==0 ) return SQLITE_OK; 1776 savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin); 1777 pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin); 1778 w.pParse = pNC->pParse; 1779 w.xExprCallback = resolveExprStep; 1780 w.xSelectCallback = resolveSelectStep; 1781 w.xSelectCallback2 = 0; 1782 w.u.pNC = pNC; 1783 #if SQLITE_MAX_EXPR_DEPTH>0 1784 w.pParse->nHeight += pExpr->nHeight; 1785 if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ 1786 return SQLITE_ERROR; 1787 } 1788 #endif 1789 sqlite3WalkExpr(&w, pExpr); 1790 #if SQLITE_MAX_EXPR_DEPTH>0 1791 w.pParse->nHeight -= pExpr->nHeight; 1792 #endif 1793 assert( EP_Agg==NC_HasAgg ); 1794 assert( EP_Win==NC_HasWin ); 1795 testcase( pNC->ncFlags & NC_HasAgg ); 1796 testcase( pNC->ncFlags & NC_HasWin ); 1797 ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); 1798 pNC->ncFlags |= savedHasAgg; 1799 return pNC->nErr>0 || w.pParse->nErr>0; 1800 } 1801 1802 /* 1803 ** Resolve all names for all expression in an expression list. This is 1804 ** just like sqlite3ResolveExprNames() except that it works for an expression 1805 ** list rather than a single expression. 1806 */ 1807 int sqlite3ResolveExprListNames( 1808 NameContext *pNC, /* Namespace to resolve expressions in. */ 1809 ExprList *pList /* The expression list to be analyzed. */ 1810 ){ 1811 int i; 1812 if( pList ){ 1813 for(i=0; i<pList->nExpr; i++){ 1814 if( sqlite3ResolveExprNames(pNC, pList->a[i].pExpr) ) return WRC_Abort; 1815 } 1816 } 1817 return WRC_Continue; 1818 } 1819 1820 /* 1821 ** Resolve all names in all expressions of a SELECT and in all 1822 ** decendents of the SELECT, including compounds off of p->pPrior, 1823 ** subqueries in expressions, and subqueries used as FROM clause 1824 ** terms. 1825 ** 1826 ** See sqlite3ResolveExprNames() for a description of the kinds of 1827 ** transformations that occur. 1828 ** 1829 ** All SELECT statements should have been expanded using 1830 ** sqlite3SelectExpand() prior to invoking this routine. 1831 */ 1832 void sqlite3ResolveSelectNames( 1833 Parse *pParse, /* The parser context */ 1834 Select *p, /* The SELECT statement being coded. */ 1835 NameContext *pOuterNC /* Name context for parent SELECT statement */ 1836 ){ 1837 Walker w; 1838 1839 assert( p!=0 ); 1840 w.xExprCallback = resolveExprStep; 1841 w.xSelectCallback = resolveSelectStep; 1842 w.xSelectCallback2 = 0; 1843 w.pParse = pParse; 1844 w.u.pNC = pOuterNC; 1845 sqlite3WalkSelect(&w, p); 1846 } 1847 1848 /* 1849 ** Resolve names in expressions that can only reference a single table 1850 ** or which cannot reference any tables at all. Examples: 1851 ** 1852 ** "type" flag 1853 ** ------------ 1854 ** (1) CHECK constraints NC_IsCheck 1855 ** (2) WHERE clauses on partial indices NC_PartIdx 1856 ** (3) Expressions in indexes on expressions NC_IdxExpr 1857 ** (4) Expression arguments to VACUUM INTO. 0 1858 ** (5) GENERATED ALWAYS as expressions NC_GenCol 1859 ** 1860 ** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN 1861 ** nodes of the expression is set to -1 and the Expr.iColumn value is 1862 ** set to the column number. In case (4), TK_COLUMN nodes cause an error. 1863 ** 1864 ** Any errors cause an error message to be set in pParse. 1865 */ 1866 int sqlite3ResolveSelfReference( 1867 Parse *pParse, /* Parsing context */ 1868 Table *pTab, /* The table being referenced, or NULL */ 1869 int type, /* NC_IsCheck, NC_PartIdx, NC_IdxExpr, NC_GenCol, or 0 */ 1870 Expr *pExpr, /* Expression to resolve. May be NULL. */ 1871 ExprList *pList /* Expression list to resolve. May be NULL. */ 1872 ){ 1873 SrcList sSrc; /* Fake SrcList for pParse->pNewTable */ 1874 NameContext sNC; /* Name context for pParse->pNewTable */ 1875 int rc; 1876 1877 assert( type==0 || pTab!=0 ); 1878 assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr 1879 || type==NC_GenCol || pTab==0 ); 1880 memset(&sNC, 0, sizeof(sNC)); 1881 memset(&sSrc, 0, sizeof(sSrc)); 1882 if( pTab ){ 1883 sSrc.nSrc = 1; 1884 sSrc.a[0].zName = pTab->zName; 1885 sSrc.a[0].pTab = pTab; 1886 sSrc.a[0].iCursor = -1; 1887 if( pTab->pSchema!=pParse->db->aDb[1].pSchema ){ 1888 /* Cause EP_FromDDL to be set on TK_FUNCTION nodes of non-TEMP 1889 ** schema elements */ 1890 type |= NC_FromDDL; 1891 } 1892 } 1893 sNC.pParse = pParse; 1894 sNC.pSrcList = &sSrc; 1895 sNC.ncFlags = type | NC_IsDDL; 1896 if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc; 1897 if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList); 1898 return rc; 1899 } 1900