/* ** Turn the pExpr expression into an alias for the iCol-th column of the ** result set in pEList. ** ** If the result set column is a simple column reference, then this routine ** makes an exact copy. But for any other kind of expression, this ** routine make a copy of the result set column as the argument to the ** TK_AS operator. The TK_AS operator causes the expression to be ** evaluated just once and then reused for each alias. ** ** The reason for suppressing the TK_AS term when the expression is a simple ** column reference is so that the column reference will be recognized as ** usable by indices within the WHERE clause processing logic. ** ** The TK_AS operator is inhibited if zType[0]=='G'. This means ** that in a GROUP BY clause, the expression is evaluated twice. Hence: ** ** SELECT random()%5 AS x, count(*) FROM tab GROUP BY x ** ** Is equivalent to: ** ** SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5 ** ** The result of random()%5 in the GROUP BY clause is probably different ** from the result in the result-set. On the other hand Standard SQL does ** not allow the GROUP BY clause to contain references to result-set columns. ** So this should never come up in well-formed queries. ** ** 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 usually 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 */ const char *zType, /* "GROUP" or "ORDER" or "" */ 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 ); assert( pOrig->flags & EP_Resolved ); db = pParse->db; pDup = sqlite3ExprDup(db, pOrig, 0); if( pDup==0 ) return; if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){ incrAggFunctionDepth(pDup, nSubquery); pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0); if( pDup==0 ) return; ExprSetProperty(pDup, EP_Skip); if( pEList->a[iCol].u.x.iAlias==0 ){ pEList->a[iCol].u.x.iAlias = (u16)(++pParse->nAlias); } pDup->iTable = pEList->a[iCol].u.x.iAlias; } if( pExpr->op==TK_COLLATE ){ pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken); } /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This ** prevents ExprDelete() from deleting the Expr structure itself, ** allowing it to be repopulated by the memcpy() on the following line. ** The pExpr->u.zToken might point into memory that will be freed by the ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to ** make a copy of the token before doing the sqlite3DbFree(). */ ExprSetProperty(pExpr, EP_Static); sqlite3ExprDelete(db, pExpr); memcpy(pExpr, pDup, sizeof(*pExpr)); if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){ assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 ); pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken); pExpr->flags |= EP_MemToken; } sqlite3DbFree(db, pDup); }
static void resolveMatchArg(Parse *pParse, NameContext *pNC, Expr *pExpr){ SrcList *pSrc = pNC->pSrcList; SrcListItem *pItem; char *zLhs; int i; if( pExpr->op!=TK_ID || pSrc==0 || pExpr==0 ){ sqlite4ErrorMsg(pParse, "first argument xxx must be a table name"); return; } zLhs = pExpr->u.zToken; for(i=0; i<pSrc->nSrc; i++){ pItem = &pSrc->a[i]; if( pItem->zAlias && sqlite4_stricmp(zLhs, pItem->zAlias)==0 ) break; if( pItem->zAlias==0 && sqlite4_stricmp(zLhs, pItem->zName)==0 ) break; } if( i==pSrc->nSrc ){ sqlite4ErrorMsg(pParse, "no such table: %s", zLhs); return; } pExpr->op = TK_NULL; pExpr->iTable = pItem->iCursor; ExprSetProperty(pExpr, EP_Resolved); }
/* ** Turn the pExpr expression into an alias for the iCol-th column of the ** result set in pEList. ** ** If the result set column is a simple column reference, then this routine ** makes an exact copy. But for any other kind of expression, this ** routine make a copy of the result set column as the argument to the ** TK_AS operator. The TK_AS operator causes the expression to be ** evaluated just once and then reused for each alias. ** ** The reason for suppressing the TK_AS term when the expression is a simple ** column reference is so that the column reference will be recognized as ** usable by indices within the WHERE clause processing logic. ** ** Hack: The TK_AS operator is inhibited if zType[0]=='G'. This means ** that in a GROUP BY clause, the expression is evaluated twice. Hence: ** ** SELECT random()%5 AS x, count(*) FROM tab GROUP BY x ** ** Is equivalent to: ** ** SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5 ** ** The result of random()%5 in the GROUP BY clause is probably different ** from the result in the result-set. We might fix this someday. Or ** then again, we might not... */ 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 */ const char *zType /* "GROUP" or "ORDER" or "" */ ){ 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 ); assert( pOrig->flags & EP_Resolved ); db = pParse->db; if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){ pDup = sqlite3ExprDup(db, pOrig, 0); pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0); if( pDup==0 ) return; if( pEList->a[iCol].iAlias==0 ){ pEList->a[iCol].iAlias = (u16)(++pParse->nAlias); } pDup->iTable = pEList->a[iCol].iAlias; }else if( ExprHasProperty(pOrig, EP_IntValue) || pOrig->u.zToken==0 ){ pDup = sqlite3ExprDup(db, pOrig, 0); if( pDup==0 ) return; }else{ char *zToken = pOrig->u.zToken; assert( zToken!=0 ); pOrig->u.zToken = 0; pDup = sqlite3ExprDup(db, pOrig, 0); pOrig->u.zToken = zToken; if( pDup==0 ) return; assert( (pDup->flags & (EP_Reduced|EP_TokenOnly))==0 ); pDup->flags2 |= EP2_MallocedToken; pDup->u.zToken = sqlite3DbStrDup(db, zToken); } if( pExpr->flags & EP_ExpCollate ){ pDup->pColl = pExpr->pColl; pDup->flags |= EP_ExpCollate; } /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This ** prevents ExprDelete() from deleting the Expr structure itself, ** allowing it to be repopulated by the memcpy() on the following line. */ ExprSetProperty(pExpr, EP_Static); sqlite3ExprDelete(db, pExpr); memcpy(pExpr, pDup, sizeof(*pExpr)); sqlite3DbFree(db, pDup); }
/* ** 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. */ ){ u8 savedHasAgg; Walker w; if( pExpr==0 ) return 0; #if SQLITE_MAX_EXPR_DEPTH>0 { Parse *pParse = pNC->pParse; if( sqlite3ExprCheckHeight(pParse, pExpr->nHeight+pNC->pParse->nHeight) ){ return 1; } pParse->nHeight += pExpr->nHeight; } #endif savedHasAgg = pNC->ncFlags & NC_HasAgg; pNC->ncFlags &= ~NC_HasAgg; memset(&w, 0, sizeof(w)); w.xExprCallback = resolveExprStep; w.xSelectCallback = resolveSelectStep; w.pParse = pNC->pParse; w.u.pNC = pNC; sqlite3WalkExpr(&w, pExpr); #if SQLITE_MAX_EXPR_DEPTH>0 pNC->pParse->nHeight -= pExpr->nHeight; #endif if( pNC->nErr>0 || w.pParse->nErr>0 ){ ExprSetProperty(pExpr, EP_Error); } if( pNC->ncFlags & NC_HasAgg ){ ExprSetProperty(pExpr, EP_Agg); }else if( savedHasAgg ){ pNC->ncFlags |= NC_HasAgg; } return ExprHasProperty(pExpr, EP_Error); }
/* ** Allocate and return a pointer to an expression to load the column iCol ** from datasource iSrc in SrcList pSrc. */ Expr *sqlite4CreateColumnExpr(sqlite4 *db, SrcList *pSrc, int iSrc, int iCol){ Expr *p = sqlite4ExprAlloc(db, TK_COLUMN, 0, 0); if( p ){ SrcListItem *pItem = &pSrc->a[iSrc]; p->pTab = pItem->pTab; p->iTable = pItem->iCursor; p->iColumn = (ynVar)iCol; testcase( iCol==BMS ); testcase( iCol==BMS-1 ); pItem->colUsed |= ((Bitmask)1)<<((iCol>=BMS || iCol<0) ? BMS-1 : iCol); ExprSetProperty(p, EP_Resolved); } return p; }
/* ** Allocate and return a pointer to an expression to load the column iCol ** from datasource iSrc datasource in SrcList pSrc. */ Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){ Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0); if( p ){ struct SrcList_item *pItem = &pSrc->a[iSrc]; p->pTab = pItem->pTab; p->iTable = pItem->iCursor; if( p->pTab->iPKey==iCol ){ p->iColumn = -1; }else{ p->iColumn = (ynVar)iCol; pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol); } ExprSetProperty(p, EP_Resolved); } return p; }
/* ** 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 ); if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return WRC_Prune; ExprSetProperty(pExpr, EP_Resolved); #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 ){ #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) /* 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. */ case TK_ROW: { SrcList *pSrcList = pNC->pSrcList; struct SrcList_item *pItem; assert( pSrcList && pSrcList->nSrc==1 ); pItem = pSrcList->a; pExpr->op = TK_COLUMN; pExpr->pTab = pItem->pTab; pExpr->iTable = pItem->iCursor; pExpr->iColumn = -1; pExpr->affinity = SQLITE_AFF_INTEGER; break; } #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */ /* A lone identifier is the name of a column. */ case TK_ID: { return lookupName(pParse, 0, 0, pExpr->u.zToken, pNC, pExpr); } /* A table name and column name: ID.ID ** Or a database, table and column: ID.ID.ID */ case TK_DOT: { const char *zColumn; const char *zTable; const char *zDb; Expr *pRight; /* if( pSrcList==0 ) break; */ pRight = pExpr->pRight; if( pRight->op==TK_ID ){ zDb = 0; zTable = pExpr->pLeft->u.zToken; zColumn = pRight->u.zToken; }else{ assert( pRight->op==TK_DOT ); zDb = pExpr->pLeft->u.zToken; zTable = pRight->pLeft->u.zToken; zColumn = pRight->pRight->u.zToken; } return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr); } /* Resolve function names */ case TK_CONST_FUNC: 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 */ int auth; /* Authorization to use the function */ int nId; /* Number of characters in function name */ const char *zId; /* The function name. */ FuncDef *pDef; /* Information about the function */ u8 enc = ENC(pParse->db); /* The database encoding */ testcase( pExpr->op==TK_CONST_FUNC ); assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); zId = pExpr->u.zToken; nId = sqlite3Strlen30(zId); pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0); if( pDef==0 ){ pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0); if( pDef==0 ){ no_such_func = 1; }else{ wrong_num_args = 1; } }else{ is_agg = pDef->xFunc==0; } #ifndef SQLITE_OMIT_AUTHORIZATION if( pDef ){ auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0); if( auth!=SQLITE_OK ){ if( auth==SQLITE_DENY ){ sqlite3ErrorMsg(pParse, "not authorized to use function: %s", pDef->zName); pNC->nErr++; } pExpr->op = TK_NULL; return WRC_Prune; } } #endif if( is_agg && !pNC->allowAgg ){ sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId); pNC->nErr++; is_agg = 0; }else if( no_such_func ){ sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); pNC->nErr++; }else if( wrong_num_args ){ sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", nId, zId); pNC->nErr++; } if( is_agg ){ pExpr->op = TK_AGG_FUNCTION; pNC->hasAgg = 1; } if( is_agg ) pNC->allowAgg = 0; sqlite3WalkExprList(pWalker, pList); if( is_agg ) pNC->allowAgg = 1; /* 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( ExprHasProperty(pExpr, EP_xIsSelect) ){ int nRef = pNC->nRef; #ifndef SQLITE_OMIT_CHECK if( pNC->isCheck ){ sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints"); } #endif sqlite3WalkSelect(pWalker, pExpr->x.pSelect); assert( pNC->nRef>=nRef ); if( nRef!=pNC->nRef ){ ExprSetProperty(pExpr, EP_VarSelect); } } break; } #ifndef SQLITE_OMIT_CHECK case TK_VARIABLE: { if( pNC->isCheck ){ sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints"); } break; } #endif } return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue; }
/* ** 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 ); if( ExprHasProperty(pExpr, EP_Resolved) ) return WRC_Prune; ExprSetProperty(pExpr, EP_Resolved); #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 ){ #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) /* 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. */ case TK_ROW: { SrcList *pSrcList = pNC->pSrcList; struct SrcList_item *pItem; assert( pSrcList && pSrcList->nSrc==1 ); pItem = pSrcList->a; pExpr->op = TK_COLUMN; pExpr->pTab = pItem->pTab; pExpr->iTable = pItem->iCursor; pExpr->iColumn = -1; pExpr->affinity = SQLITE_AFF_INTEGER; break; } #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */ /* A lone identifier is the name of a column. */ case TK_ID: { return lookupName(pParse, 0, 0, pExpr->u.zToken, pNC, pExpr); } /* A table name and column name: ID.ID ** Or a database, table and column: ID.ID.ID */ case TK_DOT: { const char *zColumn; const char *zTable; const char *zDb; Expr *pRight; /* if( pSrcList==0 ) break; */ pRight = pExpr->pRight; if( pRight->op==TK_ID ){ zDb = 0; zTable = pExpr->pLeft->u.zToken; zColumn = pRight->u.zToken; }else{ assert( pRight->op==TK_DOT ); zDb = pExpr->pLeft->u.zToken; zTable = pRight->pLeft->u.zToken; zColumn = pRight->pRight->u.zToken; } 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 */ int auth; /* Authorization to use the function */ int nId; /* Number of characters in function name */ const char *zId; /* The function name. */ FuncDef *pDef; /* Information about the function */ u8 enc = ENC(pParse->db); /* The database encoding */ assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); notValidPartIdxWhere(pParse, pNC, "functions"); zId = pExpr->u.zToken; nId = sqlite3Strlen30(zId); pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0); if( pDef==0 ){ pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0); if( pDef==0 ){ no_such_func = 1; }else{ wrong_num_args = 1; } }else{ is_agg = pDef->xFunc==0; if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){ ExprSetProperty(pExpr, EP_Unlikely|EP_Skip); if( n==2 ){ pExpr->iTable = exprProbability(pList->a[1].pExpr); if( pExpr->iTable<0 ){ sqlite3ErrorMsg(pParse, "second argument to likelihood() must be a " "constant between 0.0 and 1.0"); pNC->nErr++; } }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). */ pExpr->iTable = 62; /* TUNING: Default 2nd arg to unlikely() is 0.0625 */ } } } #ifndef SQLITE_OMIT_AUTHORIZATION if( pDef ){ auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0); if( auth!=SQLITE_OK ){ if( auth==SQLITE_DENY ){ sqlite3ErrorMsg(pParse, "not authorized to use function: %s", pDef->zName); pNC->nErr++; } pExpr->op = TK_NULL; return WRC_Prune; } if( pDef->funcFlags & SQLITE_FUNC_CONSTANT ) ExprSetProperty(pExpr,EP_Constant); } #endif if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){ sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId); pNC->nErr++; is_agg = 0; }else if( no_such_func && pParse->db->init.busy==0 ){ sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); pNC->nErr++; }else if( wrong_num_args ){ sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", nId, zId); pNC->nErr++; } if( is_agg ) pNC->ncFlags &= ~NC_AllowAgg; sqlite3WalkExprList(pWalker, pList); if( is_agg ){ NameContext *pNC2 = pNC; pExpr->op = TK_AGG_FUNCTION; pExpr->op2 = 0; while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){ pExpr->op2++; pNC2 = pNC2->pNext; } if( pNC2 ) pNC2->ncFlags |= NC_HasAgg; pNC->ncFlags |= NC_AllowAgg; } /* 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( ExprHasProperty(pExpr, EP_xIsSelect) ){ int nRef = pNC->nRef; notValidCheckConstraint(pParse, pNC, "subqueries"); notValidPartIdxWhere(pParse, pNC, "subqueries"); sqlite3WalkSelect(pWalker, pExpr->x.pSelect); assert( pNC->nRef>=nRef ); if( nRef!=pNC->nRef ){ ExprSetProperty(pExpr, EP_VarSelect); } } break; } case TK_VARIABLE: { notValidCheckConstraint(pParse, pNC, "parameters"); notValidPartIdxWhere(pParse, pNC, "parameters"); break; } } return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue; }
/* ** 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 ); if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return WRC_Prune; ExprSetProperty(pExpr, EP_Resolved); #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 ){ /* A lone identifier is the name of a column. */ case TK_ID: { lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr); return WRC_Prune; } /* A table name and column name: ID.ID ** Or a database, table and column: ID.ID.ID */ case TK_DOT: { Token *pColumn; Token *pTable; Token *pDb; Expr *pRight; /* if( pSrcList==0 ) break; */ pRight = pExpr->pRight; if( pRight->op==TK_ID ){ pDb = 0; pTable = &pExpr->pLeft->token; pColumn = &pRight->token; }else{ assert( pRight->op==TK_DOT ); pDb = &pExpr->pLeft->token; pTable = &pRight->pLeft->token; pColumn = &pRight->pRight->token; } lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr); return WRC_Prune; } /* Resolve function names */ case TK_CONST_FUNC: case TK_FUNCTION: { ExprList *pList = pExpr->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 */ int auth; /* Authorization to use the function */ int nId; /* Number of characters in function name */ const char *zId; /* The function name. */ FuncDef *pDef; /* Information about the function */ int enc = ENC(pParse->db); /* The database encoding */ zId = (char*)pExpr->token.z; nId = pExpr->token.n; pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0); if( pDef==0 ){ pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0); if( pDef==0 ){ no_such_func = 1; }else{ wrong_num_args = 1; } }else{ is_agg = pDef->xFunc==0; } #ifndef SQLITE_OMIT_AUTHORIZATION if( pDef ){ auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0); if( auth!=SQLITE_OK ){ if( auth==SQLITE_DENY ){ sqlite3ErrorMsg(pParse, "not authorized to use function: %s", pDef->zName); pNC->nErr++; } pExpr->op = TK_NULL; return WRC_Prune; } } #endif if( is_agg && !pNC->allowAgg ){ sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId); pNC->nErr++; is_agg = 0; }else if( no_such_func ){ sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); pNC->nErr++; }else if( wrong_num_args ){ sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", nId, zId); pNC->nErr++; } if( is_agg ){ pExpr->op = TK_AGG_FUNCTION; pNC->hasAgg = 1; } if( is_agg ) pNC->allowAgg = 0; sqlite3WalkExprList(pWalker, pList); if( is_agg ) pNC->allowAgg = 1; /* 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: #endif case TK_IN: { if( pExpr->pSelect ){ int nRef = pNC->nRef; #ifndef SQLITE_OMIT_CHECK if( pNC->isCheck ){ sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints"); } #endif sqlite3WalkSelect(pWalker, pExpr->pSelect); assert( pNC->nRef>=nRef ); if( nRef!=pNC->nRef ){ ExprSetProperty(pExpr, EP_VarSelect); } } break; } #ifndef SQLITE_OMIT_CHECK case TK_VARIABLE: { if( pNC->isCheck ){ sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints"); } break; } #endif } return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue; }