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Diffstat (limited to 'src/resolve.c')
| -rw-r--r-- | src/resolve.c | 2135 |
1 files changed, 2135 insertions, 0 deletions
diff --git a/src/resolve.c b/src/resolve.c new file mode 100644 index 0000000..1c3a9d9 --- /dev/null +++ b/src/resolve.c @@ -0,0 +1,2135 @@ +/* +** 2008 August 18 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** +** This file contains routines used for walking the parser tree and +** resolve all identifiers by associating them with a particular +** table and column. +*/ +#include "sqliteInt.h" + +/* +** Magic table number to mean the EXCLUDED table in an UPSERT statement. +*/ +#define EXCLUDED_TABLE_NUMBER 2 + +/* +** Walk the expression tree pExpr and increase the aggregate function +** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node. +** This needs to occur when copying a TK_AGG_FUNCTION node from an +** outer query into an inner subquery. +** +** incrAggFunctionDepth(pExpr,n) is the main routine. incrAggDepth(..) +** is a helper function - a callback for the tree walker. +** +** See also the sqlite3WindowExtraAggFuncDepth() routine in window.c +*/ +static int incrAggDepth(Walker *pWalker, Expr *pExpr){ + if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n; + return WRC_Continue; +} +static void incrAggFunctionDepth(Expr *pExpr, int N){ + if( N>0 ){ + Walker w; + memset(&w, 0, sizeof(w)); + w.xExprCallback = incrAggDepth; + w.u.n = N; + sqlite3WalkExpr(&w, pExpr); + } +} + +/* +** Turn the pExpr expression into an alias for the iCol-th column of the +** result set in pEList. +** +** If the reference is followed by a COLLATE operator, then make sure +** the COLLATE operator is preserved. For example: +** +** SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase; +** +** Should be transformed into: +** +** SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase; +** +** The nSubquery parameter specifies how many levels of subquery the +** alias is removed from the original expression. The usual value is +** zero but it might be more if the alias is contained within a subquery +** of the original expression. The Expr.op2 field of TK_AGG_FUNCTION +** structures must be increased by the nSubquery amount. +*/ +static void resolveAlias( + Parse *pParse, /* Parsing context */ + ExprList *pEList, /* A result set */ + int iCol, /* A column in the result set. 0..pEList->nExpr-1 */ + Expr *pExpr, /* Transform this into an alias to the result set */ + int nSubquery /* Number of subqueries that the label is moving */ +){ + Expr *pOrig; /* The iCol-th column of the result set */ + Expr *pDup; /* Copy of pOrig */ + sqlite3 *db; /* The database connection */ + + assert( iCol>=0 && iCol<pEList->nExpr ); + pOrig = pEList->a[iCol].pExpr; + assert( pOrig!=0 ); + db = pParse->db; + pDup = sqlite3ExprDup(db, pOrig, 0); + if( db->mallocFailed ){ + sqlite3ExprDelete(db, pDup); + pDup = 0; + }else{ + Expr temp; + incrAggFunctionDepth(pDup, nSubquery); + if( pExpr->op==TK_COLLATE ){ + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken); + } + memcpy(&temp, pDup, sizeof(Expr)); + memcpy(pDup, pExpr, sizeof(Expr)); + memcpy(pExpr, &temp, sizeof(Expr)); + if( ExprHasProperty(pExpr, EP_WinFunc) ){ + if( ALWAYS(pExpr->y.pWin!=0) ){ + pExpr->y.pWin->pOwner = pExpr; + } + } + sqlite3ExprDeferredDelete(pParse, pDup); + } +} + +/* +** Subqueries stores the original database, table and column names for their +** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN". +** Check to see if the zSpan given to this routine matches the zDb, zTab, +** and zCol. If any of zDb, zTab, and zCol are NULL then those fields will +** match anything. +*/ +int sqlite3MatchEName( + const struct ExprList_item *pItem, + const char *zCol, + const char *zTab, + const char *zDb +){ + int n; + const char *zSpan; + if( pItem->fg.eEName!=ENAME_TAB ) return 0; + zSpan = pItem->zEName; + for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} + if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){ + return 0; + } + zSpan += n+1; + for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} + if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){ + return 0; + } + zSpan += n+1; + if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){ + return 0; + } + return 1; +} + +/* +** Return TRUE if the double-quoted string mis-feature should be supported. +*/ +static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){ + if( db->init.busy ) return 1; /* Always support for legacy schemas */ + if( pTopNC->ncFlags & NC_IsDDL ){ + /* Currently parsing a DDL statement */ + if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){ + return 1; + } + return (db->flags & SQLITE_DqsDDL)!=0; + }else{ + /* Currently parsing a DML statement */ + return (db->flags & SQLITE_DqsDML)!=0; + } +} + +/* +** The argument is guaranteed to be a non-NULL Expr node of type TK_COLUMN. +** return the appropriate colUsed mask. +*/ +Bitmask sqlite3ExprColUsed(Expr *pExpr){ + int n; + Table *pExTab; + + n = pExpr->iColumn; + assert( ExprUseYTab(pExpr) ); + pExTab = pExpr->y.pTab; + assert( pExTab!=0 ); + if( (pExTab->tabFlags & TF_HasGenerated)!=0 + && (pExTab->aCol[n].colFlags & COLFLAG_GENERATED)!=0 + ){ + testcase( pExTab->nCol==BMS-1 ); + testcase( pExTab->nCol==BMS ); + return pExTab->nCol>=BMS ? ALLBITS : MASKBIT(pExTab->nCol)-1; + }else{ + testcase( n==BMS-1 ); + testcase( n==BMS ); + if( n>=BMS ) n = BMS-1; + return ((Bitmask)1)<<n; + } +} + +/* +** Create a new expression term for the column specified by pMatch and +** iColumn. Append this new expression term to the FULL JOIN Match set +** in *ppList. Create a new *ppList if this is the first term in the +** set. +*/ +static void extendFJMatch( + Parse *pParse, /* Parsing context */ + ExprList **ppList, /* ExprList to extend */ + SrcItem *pMatch, /* Source table containing the column */ + i16 iColumn /* The column number */ +){ + Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0); + if( pNew ){ + pNew->iTable = pMatch->iCursor; + pNew->iColumn = iColumn; + pNew->y.pTab = pMatch->pTab; + assert( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 ); + ExprSetProperty(pNew, EP_CanBeNull); + *ppList = sqlite3ExprListAppend(pParse, *ppList, pNew); + } +} + +/* +** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up +** that name in the set of source tables in pSrcList and make the pExpr +** expression node refer back to that source column. The following changes +** are made to pExpr: +** +** pExpr->iDb Set the index in db->aDb[] of the database X +** (even if X is implied). +** pExpr->iTable Set to the cursor number for the table obtained +** from pSrcList. +** pExpr->y.pTab Points to the Table structure of X.Y (even if +** X and/or Y are implied.) +** pExpr->iColumn Set to the column number within the table. +** pExpr->op Set to TK_COLUMN. +** pExpr->pLeft Any expression this points to is deleted +** pExpr->pRight Any expression this points to is deleted. +** +** The zDb variable is the name of the database (the "X"). This value may be +** NULL meaning that name is of the form Y.Z or Z. Any available database +** can be used. The zTable variable is the name of the table (the "Y"). This +** value can be NULL if zDb is also NULL. If zTable is NULL it +** means that the form of the name is Z and that columns from any table +** can be used. +** +** If the name cannot be resolved unambiguously, leave an error message +** in pParse and return WRC_Abort. Return WRC_Prune on success. +*/ +static int lookupName( + Parse *pParse, /* The parsing context */ + const char *zDb, /* Name of the database containing table, or NULL */ + const char *zTab, /* Name of table containing column, or NULL */ + const char *zCol, /* Name of the column. */ + NameContext *pNC, /* The name context used to resolve the name */ + Expr *pExpr /* Make this EXPR node point to the selected column */ +){ + int i, j; /* Loop counters */ + int cnt = 0; /* Number of matching column names */ + int cntTab = 0; /* Number of matching table names */ + int nSubquery = 0; /* How many levels of subquery */ + sqlite3 *db = pParse->db; /* The database connection */ + SrcItem *pItem; /* Use for looping over pSrcList items */ + SrcItem *pMatch = 0; /* The matching pSrcList item */ + NameContext *pTopNC = pNC; /* First namecontext in the list */ + Schema *pSchema = 0; /* Schema of the expression */ + int eNewExprOp = TK_COLUMN; /* New value for pExpr->op on success */ + Table *pTab = 0; /* Table holding the row */ + Column *pCol; /* A column of pTab */ + ExprList *pFJMatch = 0; /* Matches for FULL JOIN .. USING */ + + assert( pNC ); /* the name context cannot be NULL. */ + assert( zCol ); /* The Z in X.Y.Z cannot be NULL */ + assert( zDb==0 || zTab!=0 ); + assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) ); + + /* Initialize the node to no-match */ + pExpr->iTable = -1; + ExprSetVVAProperty(pExpr, EP_NoReduce); + + /* Translate the schema name in zDb into a pointer to the corresponding + ** schema. If not found, pSchema will remain NULL and nothing will match + ** resulting in an appropriate error message toward the end of this routine + */ + if( zDb ){ + testcase( pNC->ncFlags & NC_PartIdx ); + testcase( pNC->ncFlags & NC_IsCheck ); + if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){ + /* Silently ignore database qualifiers inside CHECK constraints and + ** partial indices. Do not raise errors because that might break + ** legacy and because it does not hurt anything to just ignore the + ** database name. */ + zDb = 0; + }else{ + for(i=0; i<db->nDb; i++){ + assert( db->aDb[i].zDbSName ); + if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){ + pSchema = db->aDb[i].pSchema; + break; + } + } + if( i==db->nDb && sqlite3StrICmp("main", zDb)==0 ){ + /* This branch is taken when the main database has been renamed + ** using SQLITE_DBCONFIG_MAINDBNAME. */ + pSchema = db->aDb[0].pSchema; + zDb = db->aDb[0].zDbSName; + } + } + } + + /* Start at the inner-most context and move outward until a match is found */ + assert( pNC && cnt==0 ); + do{ + ExprList *pEList; + SrcList *pSrcList = pNC->pSrcList; + + if( pSrcList ){ + for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ + u8 hCol; + pTab = pItem->pTab; + assert( pTab!=0 && pTab->zName!=0 ); + assert( pTab->nCol>0 || pParse->nErr ); + assert( (int)pItem->fg.isNestedFrom == IsNestedFrom(pItem->pSelect) ); + if( pItem->fg.isNestedFrom ){ + /* In this case, pItem is a subquery that has been formed from a + ** parenthesized subset of the FROM clause terms. Example: + ** .... FROM t1 LEFT JOIN (t2 RIGHT JOIN t3 USING(x)) USING(y) ... + ** \_________________________/ + ** This pItem -------------^ + */ + int hit = 0; + assert( pItem->pSelect!=0 ); + pEList = pItem->pSelect->pEList; + assert( pEList!=0 ); + assert( pEList->nExpr==pTab->nCol ); + for(j=0; j<pEList->nExpr; j++){ + if( !sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){ + continue; + } + if( cnt>0 ){ + if( pItem->fg.isUsing==0 + || sqlite3IdListIndex(pItem->u3.pUsing, zCol)<0 + ){ + /* Two or more tables have the same column name which is + ** not joined by USING. This is an error. Signal as much + ** by clearing pFJMatch and letting cnt go above 1. */ + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + }else + if( (pItem->fg.jointype & JT_RIGHT)==0 ){ + /* An INNER or LEFT JOIN. Use the left-most table */ + continue; + }else + if( (pItem->fg.jointype & JT_LEFT)==0 ){ + /* A RIGHT JOIN. Use the right-most table */ + cnt = 0; + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + }else{ + /* For a FULL JOIN, we must construct a coalesce() func */ + extendFJMatch(pParse, &pFJMatch, pMatch, pExpr->iColumn); + } + } + cnt++; + cntTab = 2; + pMatch = pItem; + pExpr->iColumn = j; + pEList->a[j].fg.bUsed = 1; + hit = 1; + if( pEList->a[j].fg.bUsingTerm ) break; + } + if( hit || zTab==0 ) continue; + } + assert( zDb==0 || zTab!=0 ); + if( zTab ){ + const char *zTabName; + if( zDb ){ + if( pTab->pSchema!=pSchema ) continue; + if( pSchema==0 && strcmp(zDb,"*")!=0 ) continue; + } + zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName; + assert( zTabName!=0 ); + if( sqlite3StrICmp(zTabName, zTab)!=0 ){ + continue; + } + assert( ExprUseYTab(pExpr) ); + if( IN_RENAME_OBJECT && pItem->zAlias ){ + sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab); + } + } + hCol = sqlite3StrIHash(zCol); + for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ + if( pCol->hName==hCol + && sqlite3StrICmp(pCol->zCnName, zCol)==0 + ){ + if( cnt>0 ){ + if( pItem->fg.isUsing==0 + || sqlite3IdListIndex(pItem->u3.pUsing, zCol)<0 + ){ + /* Two or more tables have the same column name which is + ** not joined by USING. This is an error. Signal as much + ** by clearing pFJMatch and letting cnt go above 1. */ + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + }else + if( (pItem->fg.jointype & JT_RIGHT)==0 ){ + /* An INNER or LEFT JOIN. Use the left-most table */ + continue; + }else + if( (pItem->fg.jointype & JT_LEFT)==0 ){ + /* A RIGHT JOIN. Use the right-most table */ + cnt = 0; + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + }else{ + /* For a FULL JOIN, we must construct a coalesce() func */ + extendFJMatch(pParse, &pFJMatch, pMatch, pExpr->iColumn); + } + } + cnt++; + pMatch = pItem; + /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ + pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j; + if( pItem->fg.isNestedFrom ){ + sqlite3SrcItemColumnUsed(pItem, j); + } + break; + } + } + if( 0==cnt && VisibleRowid(pTab) ){ + cntTab++; + pMatch = pItem; + } + } + if( pMatch ){ + pExpr->iTable = pMatch->iCursor; + assert( ExprUseYTab(pExpr) ); + pExpr->y.pTab = pMatch->pTab; + if( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 ){ + ExprSetProperty(pExpr, EP_CanBeNull); + } + pSchema = pExpr->y.pTab->pSchema; + } + } /* if( pSrcList ) */ + +#if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) + /* If we have not already resolved the name, then maybe + ** it is a new.* or old.* trigger argument reference. Or + ** maybe it is an excluded.* from an upsert. Or maybe it is + ** a reference in the RETURNING clause to a table being modified. + */ + if( cnt==0 && zDb==0 ){ + pTab = 0; +#ifndef SQLITE_OMIT_TRIGGER + if( pParse->pTriggerTab!=0 ){ + int op = pParse->eTriggerOp; + assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT ); + if( pParse->bReturning ){ + if( (pNC->ncFlags & NC_UBaseReg)!=0 + && (zTab==0 || sqlite3StrICmp(zTab,pParse->pTriggerTab->zName)==0) + ){ + pExpr->iTable = op!=TK_DELETE; + pTab = pParse->pTriggerTab; + } + }else if( op!=TK_DELETE && zTab && sqlite3StrICmp("new",zTab) == 0 ){ + pExpr->iTable = 1; + pTab = pParse->pTriggerTab; + }else if( op!=TK_INSERT && zTab && sqlite3StrICmp("old",zTab)==0 ){ + pExpr->iTable = 0; + pTab = pParse->pTriggerTab; + } + } +#endif /* SQLITE_OMIT_TRIGGER */ +#ifndef SQLITE_OMIT_UPSERT + if( (pNC->ncFlags & NC_UUpsert)!=0 && zTab!=0 ){ + Upsert *pUpsert = pNC->uNC.pUpsert; + if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){ + pTab = pUpsert->pUpsertSrc->a[0].pTab; + pExpr->iTable = EXCLUDED_TABLE_NUMBER; + } + } +#endif /* SQLITE_OMIT_UPSERT */ + + if( pTab ){ + int iCol; + u8 hCol = sqlite3StrIHash(zCol); + pSchema = pTab->pSchema; + cntTab++; + for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){ + if( pCol->hName==hCol + && sqlite3StrICmp(pCol->zCnName, zCol)==0 + ){ + if( iCol==pTab->iPKey ){ + iCol = -1; + } + break; + } + } + if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){ + /* IMP: R-51414-32910 */ + iCol = -1; + } + if( iCol<pTab->nCol ){ + cnt++; + pMatch = 0; +#ifndef SQLITE_OMIT_UPSERT + if( pExpr->iTable==EXCLUDED_TABLE_NUMBER ){ + testcase( iCol==(-1) ); + assert( ExprUseYTab(pExpr) ); + if( IN_RENAME_OBJECT ){ + pExpr->iColumn = iCol; + pExpr->y.pTab = pTab; + eNewExprOp = TK_COLUMN; + }else{ + pExpr->iTable = pNC->uNC.pUpsert->regData + + sqlite3TableColumnToStorage(pTab, iCol); + eNewExprOp = TK_REGISTER; + } + }else +#endif /* SQLITE_OMIT_UPSERT */ + { + assert( ExprUseYTab(pExpr) ); + pExpr->y.pTab = pTab; + if( pParse->bReturning ){ + eNewExprOp = TK_REGISTER; + pExpr->op2 = TK_COLUMN; + pExpr->iTable = pNC->uNC.iBaseReg + (pTab->nCol+1)*pExpr->iTable + + sqlite3TableColumnToStorage(pTab, iCol) + 1; + }else{ + pExpr->iColumn = (i16)iCol; + eNewExprOp = TK_TRIGGER; +#ifndef SQLITE_OMIT_TRIGGER + if( iCol<0 ){ + pExpr->affExpr = SQLITE_AFF_INTEGER; + }else if( pExpr->iTable==0 ){ + testcase( iCol==31 ); + testcase( iCol==32 ); + pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); + }else{ + testcase( iCol==31 ); + testcase( iCol==32 ); + pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol)); + } +#endif /* SQLITE_OMIT_TRIGGER */ + } + } + } + } + } +#endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */ + + /* + ** Perhaps the name is a reference to the ROWID + */ + if( cnt==0 + && cntTab==1 + && pMatch + && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0 + && sqlite3IsRowid(zCol) + && ALWAYS(VisibleRowid(pMatch->pTab)) + ){ + cnt = 1; + pExpr->iColumn = -1; + pExpr->affExpr = SQLITE_AFF_INTEGER; + } + + /* + ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z + ** might refer to an result-set alias. This happens, for example, when + ** we are resolving names in the WHERE clause of the following command: + ** + ** SELECT a+b AS x FROM table WHERE x<10; + ** + ** In cases like this, replace pExpr with a copy of the expression that + ** forms the result set entry ("a+b" in the example) and return immediately. + ** Note that the expression in the result set should have already been + ** resolved by the time the WHERE clause is resolved. + ** + ** The ability to use an output result-set column in the WHERE, GROUP BY, + ** or HAVING clauses, or as part of a larger expression in the ORDER BY + ** clause is not standard SQL. This is a (goofy) SQLite extension, that + ** is supported for backwards compatibility only. Hence, we issue a warning + ** on sqlite3_log() whenever the capability is used. + */ + if( cnt==0 + && (pNC->ncFlags & NC_UEList)!=0 + && zTab==0 + ){ + pEList = pNC->uNC.pEList; + assert( pEList!=0 ); + for(j=0; j<pEList->nExpr; j++){ + char *zAs = pEList->a[j].zEName; + if( pEList->a[j].fg.eEName==ENAME_NAME + && sqlite3_stricmp(zAs, zCol)==0 + ){ + Expr *pOrig; + assert( pExpr->pLeft==0 && pExpr->pRight==0 ); + assert( ExprUseXList(pExpr)==0 || pExpr->x.pList==0 ); + assert( ExprUseXSelect(pExpr)==0 || pExpr->x.pSelect==0 ); + pOrig = pEList->a[j].pExpr; + if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){ + sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs); + return WRC_Abort; + } + if( ExprHasProperty(pOrig, EP_Win) + && ((pNC->ncFlags&NC_AllowWin)==0 || pNC!=pTopNC ) + ){ + sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs); + return WRC_Abort; + } + if( sqlite3ExprVectorSize(pOrig)!=1 ){ + sqlite3ErrorMsg(pParse, "row value misused"); + return WRC_Abort; + } + resolveAlias(pParse, pEList, j, pExpr, nSubquery); + cnt = 1; + pMatch = 0; + assert( zTab==0 && zDb==0 ); + if( IN_RENAME_OBJECT ){ + sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr); + } + goto lookupname_end; + } + } + } + + /* Advance to the next name context. The loop will exit when either + ** we have a match (cnt>0) or when we run out of name contexts. + */ + if( cnt ) break; + pNC = pNC->pNext; + nSubquery++; + }while( pNC ); + + + /* + ** If X and Y are NULL (in other words if only the column name Z is + ** supplied) and the value of Z is enclosed in double-quotes, then + ** Z is a string literal if it doesn't match any column names. In that + ** case, we need to return right away and not make any changes to + ** pExpr. + ** + ** Because no reference was made to outer contexts, the pNC->nRef + ** fields are not changed in any context. + */ + if( cnt==0 && zTab==0 ){ + assert( pExpr->op==TK_ID ); + if( ExprHasProperty(pExpr,EP_DblQuoted) + && areDoubleQuotedStringsEnabled(db, pTopNC) + ){ + /* If a double-quoted identifier does not match any known column name, + ** then treat it as a string. + ** + ** This hack was added in the early days of SQLite in a misguided attempt + ** to be compatible with MySQL 3.x, which used double-quotes for strings. + ** I now sorely regret putting in this hack. The effect of this hack is + ** that misspelled identifier names are silently converted into strings + ** rather than causing an error, to the frustration of countless + ** programmers. To all those frustrated programmers, my apologies. + ** + ** Someday, I hope to get rid of this hack. Unfortunately there is + ** a huge amount of legacy SQL that uses it. So for now, we just + ** issue a warning. + */ + sqlite3_log(SQLITE_WARNING, + "double-quoted string literal: \"%w\"", zCol); +#ifdef SQLITE_ENABLE_NORMALIZE + sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol); +#endif + pExpr->op = TK_STRING; + memset(&pExpr->y, 0, sizeof(pExpr->y)); + return WRC_Prune; + } + if( sqlite3ExprIdToTrueFalse(pExpr) ){ + return WRC_Prune; + } + } + + /* + ** cnt==0 means there was not match. + ** cnt>1 means there were two or more matches. + ** + ** cnt==0 is always an error. cnt>1 is often an error, but might + ** be multiple matches for a NATURAL LEFT JOIN or a LEFT JOIN USING. + */ + assert( pFJMatch==0 || cnt>0 ); + assert( !ExprHasProperty(pExpr, EP_xIsSelect|EP_IntValue) ); + if( cnt!=1 ){ + const char *zErr; + if( pFJMatch ){ + if( pFJMatch->nExpr==cnt-1 ){ + if( ExprHasProperty(pExpr,EP_Leaf) ){ + ExprClearProperty(pExpr,EP_Leaf); + }else{ + sqlite3ExprDelete(db, pExpr->pLeft); + pExpr->pLeft = 0; + sqlite3ExprDelete(db, pExpr->pRight); + pExpr->pRight = 0; + } + extendFJMatch(pParse, &pFJMatch, pMatch, pExpr->iColumn); + pExpr->op = TK_FUNCTION; + pExpr->u.zToken = "coalesce"; + pExpr->x.pList = pFJMatch; + cnt = 1; + goto lookupname_end; + }else{ + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + } + } + zErr = cnt==0 ? "no such column" : "ambiguous column name"; + if( zDb ){ + sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol); + }else if( zTab ){ + sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol); + }else{ + sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol); + } + sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr); + pParse->checkSchema = 1; + pTopNC->nNcErr++; + } + assert( pFJMatch==0 ); + + /* Remove all substructure from pExpr */ + if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){ + sqlite3ExprDelete(db, pExpr->pLeft); + pExpr->pLeft = 0; + sqlite3ExprDelete(db, pExpr->pRight); + pExpr->pRight = 0; + ExprSetProperty(pExpr, EP_Leaf); + } + + /* If a column from a table in pSrcList is referenced, then record + ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes + ** bit 0 to be set. Column 1 sets bit 1. And so forth. Bit 63 is + ** set if the 63rd or any subsequent column is used. + ** + ** The colUsed mask is an optimization used to help determine if an + ** index is a covering index. The correct answer is still obtained + ** if the mask contains extra set bits. However, it is important to + ** avoid setting bits beyond the maximum column number of the table. + ** (See ticket [b92e5e8ec2cdbaa1]). + ** + ** If a generated column is referenced, set bits for every column + ** of the table. + */ + if( pExpr->iColumn>=0 && pMatch!=0 ){ + pMatch->colUsed |= sqlite3ExprColUsed(pExpr); + } + + pExpr->op = eNewExprOp; +lookupname_end: + if( cnt==1 ){ + assert( pNC!=0 ); +#ifndef SQLITE_OMIT_AUTHORIZATION + if( pParse->db->xAuth + && (pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER) + ){ + sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); + } +#endif + /* Increment the nRef value on all name contexts from TopNC up to + ** the point where the name matched. */ + for(;;){ + assert( pTopNC!=0 ); + pTopNC->nRef++; + if( pTopNC==pNC ) break; + pTopNC = pTopNC->pNext; + } + return WRC_Prune; + } else { + return WRC_Abort; + } +} + +/* +** Allocate and return a pointer to an expression to load the column iCol +** from datasource iSrc in SrcList pSrc. +*/ +Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){ + Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0); + if( p ){ + SrcItem *pItem = &pSrc->a[iSrc]; + Table *pTab; + assert( ExprUseYTab(p) ); + pTab = p->y.pTab = pItem->pTab; + p->iTable = pItem->iCursor; + if( p->y.pTab->iPKey==iCol ){ + p->iColumn = -1; + }else{ + p->iColumn = (ynVar)iCol; + if( (pTab->tabFlags & TF_HasGenerated)!=0 + && (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0 + ){ + testcase( pTab->nCol==63 ); + testcase( pTab->nCol==64 ); + pItem->colUsed = pTab->nCol>=64 ? ALLBITS : MASKBIT(pTab->nCol)-1; + }else{ + testcase( iCol==BMS ); + testcase( iCol==BMS-1 ); + pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol); + } + } + } + return p; +} + +/* +** Report an error that an expression is not valid for some set of +** pNC->ncFlags values determined by validMask. +** +** static void notValid( +** Parse *pParse, // Leave error message here +** NameContext *pNC, // The name context +** const char *zMsg, // Type of error +** int validMask, // Set of contexts for which prohibited +** Expr *pExpr // Invalidate this expression on error +** ){...} +** +** As an optimization, since the conditional is almost always false +** (because errors are rare), the conditional is moved outside of the +** function call using a macro. +*/ +static void notValidImpl( + Parse *pParse, /* Leave error message here */ + NameContext *pNC, /* The name context */ + const char *zMsg, /* Type of error */ + Expr *pExpr, /* Invalidate this expression on error */ + Expr *pError /* Associate error with this expression */ +){ + const char *zIn = "partial index WHERE clauses"; + if( pNC->ncFlags & NC_IdxExpr ) zIn = "index expressions"; +#ifndef SQLITE_OMIT_CHECK + else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints"; +#endif +#ifndef SQLITE_OMIT_GENERATED_COLUMNS + else if( pNC->ncFlags & NC_GenCol ) zIn = "generated columns"; +#endif + sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn); + if( pExpr ) pExpr->op = TK_NULL; + sqlite3RecordErrorOffsetOfExpr(pParse->db, pError); +} +#define sqlite3ResolveNotValid(P,N,M,X,E,R) \ + assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \ + if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E,R); + +/* +** Expression p should encode a floating point value between 1.0 and 0.0. +** Return 1024 times this value. Or return -1 if p is not a floating point +** value between 1.0 and 0.0. +*/ +static int exprProbability(Expr *p){ + double r = -1.0; + if( p->op!=TK_FLOAT ) return -1; + assert( !ExprHasProperty(p, EP_IntValue) ); + sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8); + assert( r>=0.0 ); + if( r>1.0 ) return -1; + return (int)(r*134217728.0); +} + +/* +** This routine is callback for sqlite3WalkExpr(). +** +** Resolve symbolic names into TK_COLUMN operators for the current +** node in the expression tree. Return 0 to continue the search down +** the tree or 2 to abort the tree walk. +** +** This routine also does error checking and name resolution for +** function names. The operator for aggregate functions is changed +** to TK_AGG_FUNCTION. +*/ +static int resolveExprStep(Walker *pWalker, Expr *pExpr){ + NameContext *pNC; + Parse *pParse; + + pNC = pWalker->u.pNC; + assert( pNC!=0 ); + pParse = pNC->pParse; + assert( pParse==pWalker->pParse ); + +#ifndef NDEBUG + if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ + SrcList *pSrcList = pNC->pSrcList; + int i; + for(i=0; i<pNC->pSrcList->nSrc; i++){ + assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); + } + } +#endif + switch( pExpr->op ){ + + /* The special operator TK_ROW means use the rowid for the first + ** column in the FROM clause. This is used by the LIMIT and ORDER BY + ** clause processing on UPDATE and DELETE statements, and by + ** UPDATE ... FROM statement processing. + */ + case TK_ROW: { + SrcList *pSrcList = pNC->pSrcList; + SrcItem *pItem; + assert( pSrcList && pSrcList->nSrc>=1 ); + pItem = pSrcList->a; + pExpr->op = TK_COLUMN; + assert( ExprUseYTab(pExpr) ); + pExpr->y.pTab = pItem->pTab; + pExpr->iTable = pItem->iCursor; + pExpr->iColumn--; + pExpr->affExpr = SQLITE_AFF_INTEGER; + break; + } + + /* An optimization: Attempt to convert + ** + ** "expr IS NOT NULL" --> "TRUE" + ** "expr IS NULL" --> "FALSE" + ** + ** if we can prove that "expr" is never NULL. Call this the + ** "NOT NULL strength reduction optimization". + ** + ** If this optimization occurs, also restore the NameContext ref-counts + ** to the state they where in before the "column" LHS expression was + ** resolved. This prevents "column" from being counted as having been + ** referenced, which might prevent a SELECT from being erroneously + ** marked as correlated. + */ + case TK_NOTNULL: + case TK_ISNULL: { + int anRef[8]; + NameContext *p; + int i; + for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ + anRef[i] = p->nRef; + } + sqlite3WalkExpr(pWalker, pExpr->pLeft); + if( 0==sqlite3ExprCanBeNull(pExpr->pLeft) && !IN_RENAME_OBJECT ){ + testcase( ExprHasProperty(pExpr, EP_OuterON) ); + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + if( pExpr->op==TK_NOTNULL ){ + pExpr->u.zToken = "true"; + ExprSetProperty(pExpr, EP_IsTrue); + }else{ + pExpr->u.zToken = "false"; + ExprSetProperty(pExpr, EP_IsFalse); + } + pExpr->op = TK_TRUEFALSE; + for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){ + p->nRef = anRef[i]; + } + sqlite3ExprDelete(pParse->db, pExpr->pLeft); + pExpr->pLeft = 0; + } + return WRC_Prune; + } + + /* A column name: ID + ** Or table name and column name: ID.ID + ** Or a database, table and column: ID.ID.ID + ** + ** The TK_ID and TK_OUT cases are combined so that there will only + ** be one call to lookupName(). Then the compiler will in-line + ** lookupName() for a size reduction and performance increase. + */ + case TK_ID: + case TK_DOT: { + const char *zColumn; + const char *zTable; + const char *zDb; + Expr *pRight; + + if( pExpr->op==TK_ID ){ + zDb = 0; + zTable = 0; + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + zColumn = pExpr->u.zToken; + }else{ + Expr *pLeft = pExpr->pLeft; + testcase( pNC->ncFlags & NC_IdxExpr ); + testcase( pNC->ncFlags & NC_GenCol ); + sqlite3ResolveNotValid(pParse, pNC, "the \".\" operator", + NC_IdxExpr|NC_GenCol, 0, pExpr); + pRight = pExpr->pRight; + if( pRight->op==TK_ID ){ + zDb = 0; + }else{ + assert( pRight->op==TK_DOT ); + assert( !ExprHasProperty(pRight, EP_IntValue) ); + zDb = pLeft->u.zToken; + pLeft = pRight->pLeft; + pRight = pRight->pRight; + } + assert( ExprUseUToken(pLeft) && ExprUseUToken(pRight) ); + zTable = pLeft->u.zToken; + zColumn = pRight->u.zToken; + assert( ExprUseYTab(pExpr) ); + if( IN_RENAME_OBJECT ){ + sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight); + sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft); + } + } + return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr); + } + + /* Resolve function names + */ + case TK_FUNCTION: { + ExprList *pList = pExpr->x.pList; /* The argument list */ + int n = pList ? pList->nExpr : 0; /* Number of arguments */ + int no_such_func = 0; /* True if no such function exists */ + int wrong_num_args = 0; /* True if wrong number of arguments */ + int is_agg = 0; /* True if is an aggregate function */ + const char *zId; /* The function name. */ + FuncDef *pDef; /* Information about the function */ + u8 enc = ENC(pParse->db); /* The database encoding */ + int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin)); +#ifndef SQLITE_OMIT_WINDOWFUNC + Window *pWin = (IsWindowFunc(pExpr) ? pExpr->y.pWin : 0); +#endif + assert( !ExprHasProperty(pExpr, EP_xIsSelect|EP_IntValue) ); + zId = pExpr->u.zToken; + pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0); + if( pDef==0 ){ + pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0); + if( pDef==0 ){ + no_such_func = 1; + }else{ + wrong_num_args = 1; + } + }else{ + is_agg = pDef->xFinalize!=0; + if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){ + ExprSetProperty(pExpr, EP_Unlikely); + if( n==2 ){ + pExpr->iTable = exprProbability(pList->a[1].pExpr); + if( pExpr->iTable<0 ){ + sqlite3ErrorMsg(pParse, + "second argument to %#T() must be a " + "constant between 0.0 and 1.0", pExpr); + pNC->nNcErr++; + } + }else{ + /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is + ** equivalent to likelihood(X, 0.0625). + ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is + ** short-hand for likelihood(X,0.0625). + ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand + ** for likelihood(X,0.9375). + ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent + ** to likelihood(X,0.9375). */ + /* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */ + pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120; + } + } +#ifndef SQLITE_OMIT_AUTHORIZATION + { + int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0); + if( auth!=SQLITE_OK ){ + if( auth==SQLITE_DENY ){ + sqlite3ErrorMsg(pParse, "not authorized to use function: %#T", + pExpr); + pNC->nNcErr++; + } + pExpr->op = TK_NULL; + return WRC_Prune; + } + } +#endif + if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){ + /* For the purposes of the EP_ConstFunc flag, date and time + ** functions and other functions that change slowly are considered + ** constant because they are constant for the duration of one query. + ** This allows them to be factored out of inner loops. */ + ExprSetProperty(pExpr,EP_ConstFunc); + } + if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){ + /* Clearly non-deterministic functions like random(), but also + ** date/time functions that use 'now', and other functions like + ** sqlite_version() that might change over time cannot be used + ** in an index or generated column. Curiously, they can be used + ** in a CHECK constraint. SQLServer, MySQL, and PostgreSQL all + ** all this. */ + sqlite3ResolveNotValid(pParse, pNC, "non-deterministic functions", + NC_IdxExpr|NC_PartIdx|NC_GenCol, 0, pExpr); + }else{ + assert( (NC_SelfRef & 0xff)==NC_SelfRef ); /* Must fit in 8 bits */ + pExpr->op2 = pNC->ncFlags & NC_SelfRef; + if( pNC->ncFlags & NC_FromDDL ) ExprSetProperty(pExpr, EP_FromDDL); + } + if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0 + && pParse->nested==0 + && (pParse->db->mDbFlags & DBFLAG_InternalFunc)==0 + ){ + /* Internal-use-only functions are disallowed unless the + ** SQL is being compiled using sqlite3NestedParse() or + ** the SQLITE_TESTCTRL_INTERNAL_FUNCTIONS test-control has be + ** used to activate internal functions for testing purposes */ + no_such_func = 1; + pDef = 0; + }else + if( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 + && !IN_RENAME_OBJECT + ){ + sqlite3ExprFunctionUsable(pParse, pExpr, pDef); + } + } + + if( 0==IN_RENAME_OBJECT ){ +#ifndef SQLITE_OMIT_WINDOWFUNC + assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX) + || (pDef->xValue==0 && pDef->xInverse==0) + || (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize) + ); + if( pDef && pDef->xValue==0 && pWin ){ + sqlite3ErrorMsg(pParse, + "%#T() may not be used as a window function", pExpr + ); + pNC->nNcErr++; + }else if( + (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) + || (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pWin) + || (is_agg && pWin && (pNC->ncFlags & NC_AllowWin)==0) + ){ + const char *zType; + if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pWin ){ + zType = "window"; + }else{ + zType = "aggregate"; + } + sqlite3ErrorMsg(pParse, "misuse of %s function %#T()",zType,pExpr); + pNC->nNcErr++; + is_agg = 0; + } +#else + if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){ + sqlite3ErrorMsg(pParse,"misuse of aggregate function %#T()",pExpr); + pNC->nNcErr++; + is_agg = 0; + } +#endif + else if( no_such_func && pParse->db->init.busy==0 +#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION + && pParse->explain==0 +#endif + ){ + sqlite3ErrorMsg(pParse, "no such function: %#T", pExpr); + pNC->nNcErr++; + }else if( wrong_num_args ){ + sqlite3ErrorMsg(pParse,"wrong number of arguments to function %#T()", + pExpr); + pNC->nNcErr++; + } +#ifndef SQLITE_OMIT_WINDOWFUNC + else if( is_agg==0 && ExprHasProperty(pExpr, EP_WinFunc) ){ + sqlite3ErrorMsg(pParse, + "FILTER may not be used with non-aggregate %#T()", + pExpr + ); + pNC->nNcErr++; + } +#endif + if( is_agg ){ + /* Window functions may not be arguments of aggregate functions. + ** Or arguments of other window functions. But aggregate functions + ** may be arguments for window functions. */ +#ifndef SQLITE_OMIT_WINDOWFUNC + pNC->ncFlags &= ~(NC_AllowWin | (!pWin ? NC_AllowAgg : 0)); +#else + pNC->ncFlags &= ~NC_AllowAgg; +#endif + } + } +#ifndef SQLITE_OMIT_WINDOWFUNC + else if( ExprHasProperty(pExpr, EP_WinFunc) ){ + is_agg = 1; + } +#endif + sqlite3WalkExprList(pWalker, pList); + if( is_agg ){ +#ifndef SQLITE_OMIT_WINDOWFUNC + if( pWin ){ + Select *pSel = pNC->pWinSelect; + assert( pWin==0 || (ExprUseYWin(pExpr) && pWin==pExpr->y.pWin) ); + if( IN_RENAME_OBJECT==0 ){ + sqlite3WindowUpdate(pParse, pSel ? pSel->pWinDefn : 0, pWin, pDef); + if( pParse->db->mallocFailed ) break; + } + sqlite3WalkExprList(pWalker, pWin->pPartition); + sqlite3WalkExprList(pWalker, pWin->pOrderBy); + sqlite3WalkExpr(pWalker, pWin->pFilter); + sqlite3WindowLink(pSel, pWin); + pNC->ncFlags |= NC_HasWin; + }else +#endif /* SQLITE_OMIT_WINDOWFUNC */ + { + NameContext *pNC2; /* For looping up thru outer contexts */ + pExpr->op = TK_AGG_FUNCTION; + pExpr->op2 = 0; +#ifndef SQLITE_OMIT_WINDOWFUNC + if( ExprHasProperty(pExpr, EP_WinFunc) ){ + sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter); + } +#endif + pNC2 = pNC; + while( pNC2 + && sqlite3ReferencesSrcList(pParse, pExpr, pNC2->pSrcList)==0 + ){ + pExpr->op2++; + pNC2 = pNC2->pNext; + } + assert( pDef!=0 || IN_RENAME_OBJECT ); + if( pNC2 && pDef ){ + assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg ); + assert( SQLITE_FUNC_ANYORDER==NC_OrderAgg ); + testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 ); + testcase( (pDef->funcFlags & SQLITE_FUNC_ANYORDER)!=0 ); + pNC2->ncFlags |= NC_HasAgg + | ((pDef->funcFlags^SQLITE_FUNC_ANYORDER) + & (SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER)); + } + } + pNC->ncFlags |= savedAllowFlags; + } + /* FIX ME: Compute pExpr->affinity based on the expected return + ** type of the function + */ + return WRC_Prune; + } +#ifndef SQLITE_OMIT_SUBQUERY + case TK_SELECT: + case TK_EXISTS: testcase( pExpr->op==TK_EXISTS ); +#endif + case TK_IN: { + testcase( pExpr->op==TK_IN ); + if( ExprUseXSelect(pExpr) ){ + int nRef = pNC->nRef; + testcase( pNC->ncFlags & NC_IsCheck ); + testcase( pNC->ncFlags & NC_PartIdx ); + testcase( pNC->ncFlags & NC_IdxExpr ); + testcase( pNC->ncFlags & NC_GenCol ); + if( pNC->ncFlags & NC_SelfRef ){ + notValidImpl(pParse, pNC, "subqueries", pExpr, pExpr); + }else{ + sqlite3WalkSelect(pWalker, pExpr->x.pSelect); + } + assert( pNC->nRef>=nRef ); + if( nRef!=pNC->nRef ){ + ExprSetProperty(pExpr, EP_VarSelect); + pNC->ncFlags |= NC_VarSelect; + } + } + break; + } + case TK_VARIABLE: { + testcase( pNC->ncFlags & NC_IsCheck ); + testcase( pNC->ncFlags & NC_PartIdx ); + testcase( pNC->ncFlags & NC_IdxExpr ); + testcase( pNC->ncFlags & NC_GenCol ); + sqlite3ResolveNotValid(pParse, pNC, "parameters", + NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol, pExpr, pExpr); + break; + } + case TK_IS: + case TK_ISNOT: { + Expr *pRight = sqlite3ExprSkipCollateAndLikely(pExpr->pRight); + assert( !ExprHasProperty(pExpr, EP_Reduced) ); + /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE", + ** and "x IS NOT FALSE". */ + if( ALWAYS(pRight) && (pRight->op==TK_ID || pRight->op==TK_TRUEFALSE) ){ + int rc = resolveExprStep(pWalker, pRight); + if( rc==WRC_Abort ) return WRC_Abort; + if( pRight->op==TK_TRUEFALSE ){ + pExpr->op2 = pExpr->op; + pExpr->op = TK_TRUTH; + return WRC_Continue; + } + } + /* no break */ deliberate_fall_through + } + case TK_BETWEEN: + case TK_EQ: + case TK_NE: + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: { + int nLeft, nRight; + if( pParse->db->mallocFailed ) break; + assert( pExpr->pLeft!=0 ); + nLeft = sqlite3ExprVectorSize(pExpr->pLeft); + if( pExpr->op==TK_BETWEEN ){ + assert( ExprUseXList(pExpr) ); + nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr); + if( nRight==nLeft ){ + nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr); + } + }else{ + assert( pExpr->pRight!=0 ); + nRight = sqlite3ExprVectorSize(pExpr->pRight); + } + if( nLeft!=nRight ){ + testcase( pExpr->op==TK_EQ ); + testcase( pExpr->op==TK_NE ); + testcase( pExpr->op==TK_LT ); + testcase( pExpr->op==TK_LE ); + testcase( pExpr->op==TK_GT ); + testcase( pExpr->op==TK_GE ); + testcase( pExpr->op==TK_IS ); + testcase( pExpr->op==TK_ISNOT ); + testcase( pExpr->op==TK_BETWEEN ); + sqlite3ErrorMsg(pParse, "row value misused"); + sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr); + } + break; + } + } + assert( pParse->db->mallocFailed==0 || pParse->nErr!=0 ); + return pParse->nErr ? WRC_Abort : WRC_Continue; +} + +/* +** pEList is a list of expressions which are really the result set of the +** a SELECT statement. pE is a term in an ORDER BY or GROUP BY clause. +** This routine checks to see if pE is a simple identifier which corresponds +** to the AS-name of one of the terms of the expression list. If it is, +** this routine return an integer between 1 and N where N is the number of +** elements in pEList, corresponding to the matching entry. If there is +** no match, or if pE is not a simple identifier, then this routine +** return 0. +** +** pEList has been resolved. pE has not. +*/ +static int resolveAsName( + Parse *pParse, /* Parsing context for error messages */ + ExprList *pEList, /* List of expressions to scan */ + Expr *pE /* Expression we are trying to match */ +){ + int i; /* Loop counter */ + + UNUSED_PARAMETER(pParse); + + if( pE->op==TK_ID ){ + const char *zCol; + assert( !ExprHasProperty(pE, EP_IntValue) ); + zCol = pE->u.zToken; + for(i=0; i<pEList->nExpr; i++){ + if( pEList->a[i].fg.eEName==ENAME_NAME + && sqlite3_stricmp(pEList->a[i].zEName, zCol)==0 + ){ + return i+1; + } + } + } + return 0; +} + +/* +** pE is a pointer to an expression which is a single term in the +** ORDER BY of a compound SELECT. The expression has not been +** name resolved. +** +** At the point this routine is called, we already know that the +** ORDER BY term is not an integer index into the result set. That +** case is handled by the calling routine. +** +** Attempt to match pE against result set columns in the left-most +** SELECT statement. Return the index i of the matching column, +** as an indication to the caller that it should sort by the i-th column. +** The left-most column is 1. In other words, the value returned is the +** same integer value that would be used in the SQL statement to indicate +** the column. +** +** If there is no match, return 0. Return -1 if an error occurs. +*/ +static int resolveOrderByTermToExprList( + Parse *pParse, /* Parsing context for error messages */ + Select *pSelect, /* The SELECT statement with the ORDER BY clause */ + Expr *pE /* The specific ORDER BY term */ +){ + int i; /* Loop counter */ + ExprList *pEList; /* The columns of the result set */ + NameContext nc; /* Name context for resolving pE */ + sqlite3 *db; /* Database connection */ + int rc; /* Return code from subprocedures */ + u8 savedSuppErr; /* Saved value of db->suppressErr */ + + assert( sqlite3ExprIsInteger(pE, &i)==0 ); + pEList = pSelect->pEList; + + /* Resolve all names in the ORDER BY term expression + */ + memset(&nc, 0, sizeof(nc)); + nc.pParse = pParse; + nc.pSrcList = pSelect->pSrc; + nc.uNC.pEList = pEList; + nc.ncFlags = NC_AllowAgg|NC_UEList|NC_NoSelect; + nc.nNcErr = 0; + db = pParse->db; + savedSuppErr = db->suppressErr; + db->suppressErr = 1; + rc = sqlite3ResolveExprNames(&nc, pE); + db->suppressErr = savedSuppErr; + if( rc ) return 0; + + /* Try to match the ORDER BY expression against an expression + ** in the result set. Return an 1-based index of the matching + ** result-set entry. + */ + for(i=0; i<pEList->nExpr; i++){ + if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){ + return i+1; + } + } + + /* If no match, return 0. */ + return 0; +} + +/* +** Generate an ORDER BY or GROUP BY term out-of-range error. +*/ +static void resolveOutOfRangeError( + Parse *pParse, /* The error context into which to write the error */ + const char *zType, /* "ORDER" or "GROUP" */ + int i, /* The index (1-based) of the term out of range */ + int mx, /* Largest permissible value of i */ + Expr *pError /* Associate the error with the expression */ +){ + sqlite3ErrorMsg(pParse, + "%r %s BY term out of range - should be " + "between 1 and %d", i, zType, mx); + sqlite3RecordErrorOffsetOfExpr(pParse->db, pError); +} + +/* +** Analyze the ORDER BY clause in a compound SELECT statement. Modify +** each term of the ORDER BY clause is a constant integer between 1 +** and N where N is the number of columns in the compound SELECT. +** +** ORDER BY terms that are already an integer between 1 and N are +** unmodified. ORDER BY terms that are integers outside the range of +** 1 through N generate an error. ORDER BY terms that are expressions +** are matched against result set expressions of compound SELECT +** beginning with the left-most SELECT and working toward the right. +** At the first match, the ORDER BY expression is transformed into +** the integer column number. +** +** Return the number of errors seen. +*/ +static int resolveCompoundOrderBy( + Parse *pParse, /* Parsing context. Leave error messages here */ + Select *pSelect /* The SELECT statement containing the ORDER BY */ +){ + int i; + ExprList *pOrderBy; + ExprList *pEList; + sqlite3 *db; + int moreToDo = 1; + + pOrderBy = pSelect->pOrderBy; + if( pOrderBy==0 ) return 0; + db = pParse->db; + if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ + sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause"); + return 1; + } + for(i=0; i<pOrderBy->nExpr; i++){ + pOrderBy->a[i].fg.done = 0; + } + pSelect->pNext = 0; + while( pSelect->pPrior ){ + pSelect->pPrior->pNext = pSelect; + pSelect = pSelect->pPrior; + } + while( pSelect && moreToDo ){ + struct ExprList_item *pItem; + moreToDo = 0; + pEList = pSelect->pEList; + assert( pEList!=0 ); + for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ + int iCol = -1; + Expr *pE, *pDup; + if( pItem->fg.done ) continue; + pE = sqlite3ExprSkipCollateAndLikely(pItem->pExpr); + if( NEVER(pE==0) ) continue; + if( sqlite3ExprIsInteger(pE, &iCol) ){ + if( iCol<=0 || iCol>pEList->nExpr ){ + resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr, pE); + return 1; + } + }else{ + iCol = resolveAsName(pParse, pEList, pE); + if( iCol==0 ){ + /* Now test if expression pE matches one of the values returned + ** by pSelect. In the usual case this is done by duplicating the + ** expression, resolving any symbols in it, and then comparing + ** it against each expression returned by the SELECT statement. + ** Once the comparisons are finished, the duplicate expression + ** is deleted. + ** + ** If this is running as part of an ALTER TABLE operation and + ** the symbols resolve successfully, also resolve the symbols in the + ** actual expression. This allows the code in alter.c to modify + ** column references within the ORDER BY expression as required. */ + pDup = sqlite3ExprDup(db, pE, 0); + if( !db->mallocFailed ){ + assert(pDup); + iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup); + if( IN_RENAME_OBJECT && iCol>0 ){ + resolveOrderByTermToExprList(pParse, pSelect, pE); + } + } + sqlite3ExprDelete(db, pDup); + } + } + if( iCol>0 ){ + /* Convert the ORDER BY term into an integer column number iCol, + ** taking care to preserve the COLLATE clause if it exists. */ + if( !IN_RENAME_OBJECT ){ + Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); + if( pNew==0 ) return 1; + pNew->flags |= EP_IntValue; + pNew->u.iValue = iCol; + if( pItem->pExpr==pE ){ + pItem->pExpr = pNew; + }else{ + Expr *pParent = pItem->pExpr; + assert( pParent->op==TK_COLLATE ); + while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft; + assert( pParent->pLeft==pE ); + pParent->pLeft = pNew; + } + sqlite3ExprDelete(db, pE); + pItem->u.x.iOrderByCol = (u16)iCol; + } + pItem->fg.done = 1; + }else{ + moreToDo = 1; + } + } + pSelect = pSelect->pNext; + } + for(i=0; i<pOrderBy->nExpr; i++){ + if( pOrderBy->a[i].fg.done==0 ){ + sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any " + "column in the result set", i+1); + return 1; + } + } + return 0; +} + +/* +** Check every term in the ORDER BY or GROUP BY clause pOrderBy of +** the SELECT statement pSelect. If any term is reference to a +** result set expression (as determined by the ExprList.a.u.x.iOrderByCol +** field) then convert that term into a copy of the corresponding result set +** column. +** +** If any errors are detected, add an error message to pParse and +** return non-zero. Return zero if no errors are seen. +*/ +int sqlite3ResolveOrderGroupBy( + Parse *pParse, /* Parsing context. Leave error messages here */ + Select *pSelect, /* The SELECT statement containing the clause */ + ExprList *pOrderBy, /* The ORDER BY or GROUP BY clause to be processed */ + const char *zType /* "ORDER" or "GROUP" */ +){ + int i; + sqlite3 *db = pParse->db; + ExprList *pEList; + struct ExprList_item *pItem; + + if( pOrderBy==0 || pParse->db->mallocFailed || IN_RENAME_OBJECT ) return 0; + if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ + sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType); + return 1; + } + pEList = pSelect->pEList; + assert( pEList!=0 ); /* sqlite3SelectNew() guarantees this */ + for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ + if( pItem->u.x.iOrderByCol ){ + if( pItem->u.x.iOrderByCol>pEList->nExpr ){ + resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr, 0); + return 1; + } + resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,0); + } + } + return 0; +} + +#ifndef SQLITE_OMIT_WINDOWFUNC +/* +** Walker callback for windowRemoveExprFromSelect(). +*/ +static int resolveRemoveWindowsCb(Walker *pWalker, Expr *pExpr){ + UNUSED_PARAMETER(pWalker); + if( ExprHasProperty(pExpr, EP_WinFunc) ){ + Window *pWin = pExpr->y.pWin; + sqlite3WindowUnlinkFromSelect(pWin); + } + return WRC_Continue; +} + +/* +** Remove any Window objects owned by the expression pExpr from the +** Select.pWin list of Select object pSelect. +*/ +static void windowRemoveExprFromSelect(Select *pSelect, Expr *pExpr){ + if( pSelect->pWin ){ + Walker sWalker; + memset(&sWalker, 0, sizeof(Walker)); + sWalker.xExprCallback = resolveRemoveWindowsCb; + sWalker.u.pSelect = pSelect; + sqlite3WalkExpr(&sWalker, pExpr); + } +} +#else +# define windowRemoveExprFromSelect(a, b) +#endif /* SQLITE_OMIT_WINDOWFUNC */ + +/* +** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect. +** The Name context of the SELECT statement is pNC. zType is either +** "ORDER" or "GROUP" depending on which type of clause pOrderBy is. +** +** This routine resolves each term of the clause into an expression. +** If the order-by term is an integer I between 1 and N (where N is the +** number of columns in the result set of the SELECT) then the expression +** in the resolution is a copy of the I-th result-set expression. If +** the order-by term is an identifier that corresponds to the AS-name of +** a result-set expression, then the term resolves to a copy of the +** result-set expression. Otherwise, the expression is resolved in +** the usual way - using sqlite3ResolveExprNames(). +** +** This routine returns the number of errors. If errors occur, then +** an appropriate error message might be left in pParse. (OOM errors +** excepted.) +*/ +static int resolveOrderGroupBy( + NameContext *pNC, /* The name context of the SELECT statement */ + Select *pSelect, /* The SELECT statement holding pOrderBy */ + ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */ + const char *zType /* Either "ORDER" or "GROUP", as appropriate */ +){ + int i, j; /* Loop counters */ + int iCol; /* Column number */ + struct ExprList_item *pItem; /* A term of the ORDER BY clause */ + Parse *pParse; /* Parsing context */ + int nResult; /* Number of terms in the result set */ + + assert( pOrderBy!=0 ); + nResult = pSelect->pEList->nExpr; + pParse = pNC->pParse; + for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ + Expr *pE = pItem->pExpr; + Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pE); + if( NEVER(pE2==0) ) continue; + if( zType[0]!='G' ){ + iCol = resolveAsName(pParse, pSelect->pEList, pE2); + if( iCol>0 ){ + /* If an AS-name match is found, mark this ORDER BY column as being + ** a copy of the iCol-th result-set column. The subsequent call to + ** sqlite3ResolveOrderGroupBy() will convert the expression to a + ** copy of the iCol-th result-set expression. */ + pItem->u.x.iOrderByCol = (u16)iCol; + continue; + } + } + if( sqlite3ExprIsInteger(pE2, &iCol) ){ + /* The ORDER BY term is an integer constant. Again, set the column + ** number so that sqlite3ResolveOrderGroupBy() will convert the + ** order-by term to a copy of the result-set expression */ + if( iCol<1 || iCol>0xffff ){ + resolveOutOfRangeError(pParse, zType, i+1, nResult, pE2); + return 1; + } + pItem->u.x.iOrderByCol = (u16)iCol; + continue; + } + + /* Otherwise, treat the ORDER BY term as an ordinary expression */ + pItem->u.x.iOrderByCol = 0; + if( sqlite3ResolveExprNames(pNC, pE) ){ + return 1; + } + for(j=0; j<pSelect->pEList->nExpr; j++){ + if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){ + /* Since this expresion is being changed into a reference + ** to an identical expression in the result set, remove all Window + ** objects belonging to the expression from the Select.pWin list. */ + windowRemoveExprFromSelect(pSelect, pE); + pItem->u.x.iOrderByCol = j+1; + } + } + } + return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType); +} + +/* +** Resolve names in the SELECT statement p and all of its descendants. +*/ +static int resolveSelectStep(Walker *pWalker, Select *p){ + NameContext *pOuterNC; /* Context that contains this SELECT */ + NameContext sNC; /* Name context of this SELECT */ + int isCompound; /* True if p is a compound select */ + int nCompound; /* Number of compound terms processed so far */ + Parse *pParse; /* Parsing context */ + int i; /* Loop counter */ + ExprList *pGroupBy; /* The GROUP BY clause */ + Select *pLeftmost; /* Left-most of SELECT of a compound */ + sqlite3 *db; /* Database connection */ + + + assert( p!=0 ); + if( p->selFlags & SF_Resolved ){ + return WRC_Prune; + } + pOuterNC = pWalker->u.pNC; + pParse = pWalker->pParse; + db = pParse->db; + + /* Normally sqlite3SelectExpand() will be called first and will have + ** already expanded this SELECT. However, if this is a subquery within + ** an expression, sqlite3ResolveExprNames() will be called without a + ** prior call to sqlite3SelectExpand(). When that happens, let + ** sqlite3SelectPrep() do all of the processing for this SELECT. + ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and + ** this routine in the correct order. + */ + if( (p->selFlags & SF_Expanded)==0 ){ + sqlite3SelectPrep(pParse, p, pOuterNC); + return pParse->nErr ? WRC_Abort : WRC_Prune; + } + + isCompound = p->pPrior!=0; + nCompound = 0; + pLeftmost = p; + while( p ){ + assert( (p->selFlags & SF_Expanded)!=0 ); + assert( (p->selFlags & SF_Resolved)==0 ); + assert( db->suppressErr==0 ); /* SF_Resolved not set if errors suppressed */ + p->selFlags |= SF_Resolved; + + + /* Resolve the expressions in the LIMIT and OFFSET clauses. These + ** are not allowed to refer to any names, so pass an empty NameContext. + */ + memset(&sNC, 0, sizeof(sNC)); + sNC.pParse = pParse; + sNC.pWinSelect = p; + if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){ + return WRC_Abort; + } + + /* If the SF_Converted flags is set, then this Select object was + ** was created by the convertCompoundSelectToSubquery() function. + ** In this case the ORDER BY clause (p->pOrderBy) should be resolved + ** as if it were part of the sub-query, not the parent. This block + ** moves the pOrderBy down to the sub-query. It will be moved back + ** after the names have been resolved. */ + if( p->selFlags & SF_Converted ){ + Select *pSub = p->pSrc->a[0].pSelect; + assert( p->pSrc->nSrc==1 && p->pOrderBy ); + assert( pSub->pPrior && pSub->pOrderBy==0 ); + pSub->pOrderBy = p->pOrderBy; + p->pOrderBy = 0; + } + + /* Recursively resolve names in all subqueries in the FROM clause + */ + for(i=0; i<p->pSrc->nSrc; i++){ + SrcItem *pItem = &p->pSrc->a[i]; + if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){ + int nRef = pOuterNC ? pOuterNC->nRef : 0; + const char *zSavedContext = pParse->zAuthContext; + + if( pItem->zName ) pParse->zAuthContext = pItem->zName; + sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC); + pParse->zAuthContext = zSavedContext; + if( pParse->nErr ) return WRC_Abort; + assert( db->mallocFailed==0 ); + + /* If the number of references to the outer context changed when + ** expressions in the sub-select were resolved, the sub-select + ** is correlated. It is not required to check the refcount on any + ** but the innermost outer context object, as lookupName() increments + ** the refcount on all contexts between the current one and the + ** context containing the column when it resolves a name. */ + if( pOuterNC ){ + assert( pItem->fg.isCorrelated==0 && pOuterNC->nRef>=nRef ); + pItem->fg.isCorrelated = (pOuterNC->nRef>nRef); + } + } + } + + /* Set up the local name-context to pass to sqlite3ResolveExprNames() to + ** resolve the result-set expression list. + */ + sNC.ncFlags = NC_AllowAgg|NC_AllowWin; + sNC.pSrcList = p->pSrc; + sNC.pNext = pOuterNC; + + /* Resolve names in the result set. */ + if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort; + sNC.ncFlags &= ~NC_AllowWin; + + /* If there are no aggregate functions in the result-set, and no GROUP BY + ** expression, do not allow aggregates in any of the other expressions. + */ + assert( (p->selFlags & SF_Aggregate)==0 ); + pGroupBy = p->pGroupBy; + if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){ + assert( NC_MinMaxAgg==SF_MinMaxAgg ); + assert( NC_OrderAgg==SF_OrderByReqd ); + p->selFlags |= SF_Aggregate | (sNC.ncFlags&(NC_MinMaxAgg|NC_OrderAgg)); + }else{ + sNC.ncFlags &= ~NC_AllowAgg; + } + + /* Add the output column list to the name-context before parsing the + ** other expressions in the SELECT statement. This is so that + ** expressions in the WHERE clause (etc.) can refer to expressions by + ** aliases in the result set. + ** + ** Minor point: If this is the case, then the expression will be + ** re-evaluated for each reference to it. + */ + assert( (sNC.ncFlags & (NC_UAggInfo|NC_UUpsert|NC_UBaseReg))==0 ); + sNC.uNC.pEList = p->pEList; + sNC.ncFlags |= NC_UEList; + if( p->pHaving ){ + if( (p->selFlags & SF_Aggregate)==0 ){ + sqlite3ErrorMsg(pParse, "HAVING clause on a non-aggregate query"); + return WRC_Abort; + } + if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort; + } + if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort; + + /* Resolve names in table-valued-function arguments */ + for(i=0; i<p->pSrc->nSrc; i++){ + SrcItem *pItem = &p->pSrc->a[i]; + if( pItem->fg.isTabFunc + && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) + ){ + return WRC_Abort; + } + } + +#ifndef SQLITE_OMIT_WINDOWFUNC + if( IN_RENAME_OBJECT ){ + Window *pWin; + for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){ + if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy) + || sqlite3ResolveExprListNames(&sNC, pWin->pPartition) + ){ + return WRC_Abort; + } + } + } +#endif + + /* The ORDER BY and GROUP BY clauses may not refer to terms in + ** outer queries + */ + sNC.pNext = 0; + sNC.ncFlags |= NC_AllowAgg|NC_AllowWin; + + /* If this is a converted compound query, move the ORDER BY clause from + ** the sub-query back to the parent query. At this point each term + ** within the ORDER BY clause has been transformed to an integer value. + ** These integers will be replaced by copies of the corresponding result + ** set expressions by the call to resolveOrderGroupBy() below. */ + if( p->selFlags & SF_Converted ){ + Select *pSub = p->pSrc->a[0].pSelect; + p->pOrderBy = pSub->pOrderBy; + pSub->pOrderBy = 0; + } + + /* Process the ORDER BY clause for singleton SELECT statements. + ** The ORDER BY clause for compounds SELECT statements is handled + ** below, after all of the result-sets for all of the elements of + ** the compound have been resolved. + ** + ** If there is an ORDER BY clause on a term of a compound-select other + ** than the right-most term, then that is a syntax error. But the error + ** is not detected until much later, and so we need to go ahead and + ** resolve those symbols on the incorrect ORDER BY for consistency. + */ + if( p->pOrderBy!=0 + && isCompound<=nCompound /* Defer right-most ORDER BY of a compound */ + && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") + ){ + return WRC_Abort; + } + if( db->mallocFailed ){ + return WRC_Abort; + } + sNC.ncFlags &= ~NC_AllowWin; + + /* Resolve the GROUP BY clause. At the same time, make sure + ** the GROUP BY clause does not contain aggregate functions. + */ + if( pGroupBy ){ + struct ExprList_item *pItem; + + if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){ + return WRC_Abort; + } + for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){ + if( ExprHasProperty(pItem->pExpr, EP_Agg) ){ + sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in " + "the GROUP BY clause"); + return WRC_Abort; + } + } + } + + /* If this is part of a compound SELECT, check that it has the right + ** number of expressions in the select list. */ + if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){ + sqlite3SelectWrongNumTermsError(pParse, p->pNext); + return WRC_Abort; + } + + /* Advance to the next term of the compound + */ + p = p->pPrior; + nCompound++; + } + + /* Resolve the ORDER BY on a compound SELECT after all terms of + ** the compound have been resolved. + */ + if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){ + return WRC_Abort; + } + + return WRC_Prune; +} + +/* +** This routine walks an expression tree and resolves references to +** table columns and result-set columns. At the same time, do error +** checking on function usage and set a flag if any aggregate functions +** are seen. +** +** To resolve table columns references we look for nodes (or subtrees) of the +** form X.Y.Z or Y.Z or just Z where +** +** X: The name of a database. Ex: "main" or "temp" or +** the symbolic name assigned to an ATTACH-ed database. +** +** Y: The name of a table in a FROM clause. Or in a trigger +** one of the special names "old" or "new". +** +** Z: The name of a column in table Y. +** +** The node at the root of the subtree is modified as follows: +** +** Expr.op Changed to TK_COLUMN +** Expr.pTab Points to the Table object for X.Y +** Expr.iColumn The column index in X.Y. -1 for the rowid. +** Expr.iTable The VDBE cursor number for X.Y +** +** +** To resolve result-set references, look for expression nodes of the +** form Z (with no X and Y prefix) where the Z matches the right-hand +** size of an AS clause in the result-set of a SELECT. The Z expression +** is replaced by a copy of the left-hand side of the result-set expression. +** Table-name and function resolution occurs on the substituted expression +** tree. For example, in: +** +** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x; +** +** The "x" term of the order by is replaced by "a+b" to render: +** +** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b; +** +** Function calls are checked to make sure that the function is +** defined and that the correct number of arguments are specified. +** If the function is an aggregate function, then the NC_HasAgg flag is +** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION. +** If an expression contains aggregate functions then the EP_Agg +** property on the expression is set. +** +** An error message is left in pParse if anything is amiss. The number +** if errors is returned. +*/ +int sqlite3ResolveExprNames( + NameContext *pNC, /* Namespace to resolve expressions in. */ + Expr *pExpr /* The expression to be analyzed. */ +){ + int savedHasAgg; + Walker w; + + if( pExpr==0 ) return SQLITE_OK; + savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); + pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); + w.pParse = pNC->pParse; + w.xExprCallback = resolveExprStep; + w.xSelectCallback = (pNC->ncFlags & NC_NoSelect) ? 0 : resolveSelectStep; + w.xSelectCallback2 = 0; + w.u.pNC = pNC; +#if SQLITE_MAX_EXPR_DEPTH>0 + w.pParse->nHeight += pExpr->nHeight; + if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ + return SQLITE_ERROR; + } +#endif + sqlite3WalkExpr(&w, pExpr); +#if SQLITE_MAX_EXPR_DEPTH>0 + w.pParse->nHeight -= pExpr->nHeight; +#endif + assert( EP_Agg==NC_HasAgg ); + assert( EP_Win==NC_HasWin ); + testcase( pNC->ncFlags & NC_HasAgg ); + testcase( pNC->ncFlags & NC_HasWin ); + ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); + pNC->ncFlags |= savedHasAgg; + return pNC->nNcErr>0 || w.pParse->nErr>0; +} + +/* +** Resolve all names for all expression in an expression list. This is +** just like sqlite3ResolveExprNames() except that it works for an expression +** list rather than a single expression. +*/ +int sqlite3ResolveExprListNames( + NameContext *pNC, /* Namespace to resolve expressions in. */ + ExprList *pList /* The expression list to be analyzed. */ +){ + int i; + int savedHasAgg = 0; + Walker w; + if( pList==0 ) return WRC_Continue; + w.pParse = pNC->pParse; + w.xExprCallback = resolveExprStep; + w.xSelectCallback = resolveSelectStep; + w.xSelectCallback2 = 0; + w.u.pNC = pNC; + savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); + pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); + for(i=0; i<pList->nExpr; i++){ + Expr *pExpr = pList->a[i].pExpr; + if( pExpr==0 ) continue; +#if SQLITE_MAX_EXPR_DEPTH>0 + w.pParse->nHeight += pExpr->nHeight; + if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){ + return WRC_Abort; + } +#endif + sqlite3WalkExpr(&w, pExpr); +#if SQLITE_MAX_EXPR_DEPTH>0 + w.pParse->nHeight -= pExpr->nHeight; +#endif + assert( EP_Agg==NC_HasAgg ); + assert( EP_Win==NC_HasWin ); + testcase( pNC->ncFlags & NC_HasAgg ); + testcase( pNC->ncFlags & NC_HasWin ); + if( pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg) ){ + ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) ); + savedHasAgg |= pNC->ncFlags & + (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); + pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg); + } + if( w.pParse->nErr>0 ) return WRC_Abort; + } + pNC->ncFlags |= savedHasAgg; + return WRC_Continue; +} + +/* +** Resolve all names in all expressions of a SELECT and in all +** decendents of the SELECT, including compounds off of p->pPrior, +** subqueries in expressions, and subqueries used as FROM clause +** terms. +** +** See sqlite3ResolveExprNames() for a description of the kinds of +** transformations that occur. +** +** All SELECT statements should have been expanded using +** sqlite3SelectExpand() prior to invoking this routine. +*/ +void sqlite3ResolveSelectNames( + Parse *pParse, /* The parser context */ + Select *p, /* The SELECT statement being coded. */ + NameContext *pOuterNC /* Name context for parent SELECT statement */ +){ + Walker w; + + assert( p!=0 ); + w.xExprCallback = resolveExprStep; + w.xSelectCallback = resolveSelectStep; + w.xSelectCallback2 = 0; + w.pParse = pParse; + w.u.pNC = pOuterNC; + sqlite3WalkSelect(&w, p); +} + +/* +** Resolve names in expressions that can only reference a single table +** or which cannot reference any tables at all. Examples: +** +** "type" flag +** ------------ +** (1) CHECK constraints NC_IsCheck +** (2) WHERE clauses on partial indices NC_PartIdx +** (3) Expressions in indexes on expressions NC_IdxExpr +** (4) Expression arguments to VACUUM INTO. 0 +** (5) GENERATED ALWAYS as expressions NC_GenCol +** +** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN +** nodes of the expression is set to -1 and the Expr.iColumn value is +** set to the column number. In case (4), TK_COLUMN nodes cause an error. +** +** Any errors cause an error message to be set in pParse. +*/ +int sqlite3ResolveSelfReference( + Parse *pParse, /* Parsing context */ + Table *pTab, /* The table being referenced, or NULL */ + int type, /* NC_IsCheck, NC_PartIdx, NC_IdxExpr, NC_GenCol, or 0 */ + Expr *pExpr, /* Expression to resolve. May be NULL. */ + ExprList *pList /* Expression list to resolve. May be NULL. */ +){ + SrcList sSrc; /* Fake SrcList for pParse->pNewTable */ + NameContext sNC; /* Name context for pParse->pNewTable */ + int rc; + + assert( type==0 || pTab!=0 ); + assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr + || type==NC_GenCol || pTab==0 ); + memset(&sNC, 0, sizeof(sNC)); + memset(&sSrc, 0, sizeof(sSrc)); + if( pTab ){ + sSrc.nSrc = 1; + sSrc.a[0].zName = pTab->zName; + sSrc.a[0].pTab = pTab; + sSrc.a[0].iCursor = -1; + if( pTab->pSchema!=pParse->db->aDb[1].pSchema ){ + /* Cause EP_FromDDL to be set on TK_FUNCTION nodes of non-TEMP + ** schema elements */ + type |= NC_FromDDL; + } + } + sNC.pParse = pParse; + sNC.pSrcList = &sSrc; + sNC.ncFlags = type | NC_IsDDL; + if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc; + if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList); + return rc; +} |