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Teach query_tree_walker, query_tree_mutator, and SS_finalize_plan to

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process function RTE expressions, which they were previously missing.
This allows outer-Var references and subselects to work correctly in
the arguments of a function RTE.  Install check to prevent function RTEs
from cross-referencing Vars of sibling FROM-items, which doesn't make
any sense (if you want to join, write a JOIN or WHERE clause).
This commit is contained in:
Tom Lane
2002-05-18 18:49:41 +00:00
parent 2c50f6344b
commit a5b370943e
5 changed files with 87 additions and 41 deletions
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51
src/backend/parser/parse_clause.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.92 2002/05/12 23:43:03 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.93 2002/05/18 18:49:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -410,7 +410,9 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r)
*/
save_namespace = pstate->p_namespace;
pstate->p_namespace = NIL;
parsetrees = parse_analyze(r->subquery, pstate);
pstate->p_namespace = save_namespace;
/*
@ -455,26 +457,49 @@ transformRangeFunction(ParseState *pstate, RangeFunction *r)
{
Node *funcexpr;
char *funcname;
List *save_namespace;
RangeTblEntry *rte;
RangeTblRef *rtr;
/*
* Transform the raw FuncCall node
*/
funcexpr = transformExpr(pstate, r->funccallnode);
/* Get function name for possible use as alias */
Assert(IsA(r->funccallnode, FuncCall));
funcname = strVal(llast(((FuncCall *) r->funccallnode)->funcname));
/*
* Disallow aggregate functions and subselects in the expression.
* (Aggregates clearly make no sense; perhaps later we could support
* subselects, though.)
* Transform the raw FuncCall node. This is a bit tricky because we don't
* want the function expression to be able to see any FROM items already
* created in the current query (compare to transformRangeSubselect).
* But it does need to be able to see any further-up parent states.
* So, temporarily make the current query level have an empty namespace.
* NOTE: this code is OK only because the expression can't legally alter
* the namespace by causing implicit relation refs to be added.
*/
if (contain_agg_clause(funcexpr))
elog(ERROR, "cannot use aggregate function in FROM function expression");
if (contain_subplans(funcexpr))
elog(ERROR, "cannot use subselect in FROM function expression");
save_namespace = pstate->p_namespace;
pstate->p_namespace = NIL;
funcexpr = transformExpr(pstate, r->funccallnode);
pstate->p_namespace = save_namespace;
/*
* We still need to check that the function parameters don't refer
* to any other rels. That could happen despite our hack on the namespace
* if fully-qualified names are used. So, check there are no local
* Var references in the transformed expression. (Outer references
* are OK, and are ignored here.)
*/
if (pull_varnos(funcexpr) != NIL)
elog(ERROR, "FROM function expression may not refer to other relations of same query level");
/*
* Disallow aggregate functions in the expression. (No reason to postpone
* this check until parseCheckAggregates.)
*/
if (pstate->p_hasAggs)
{
if (contain_agg_clause(funcexpr))
elog(ERROR, "cannot use aggregate function in FROM function expression");
}
/*
* Insist we have a bare function call (explain.c is the only place