/*
** 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;
}
