* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.262 2003/02/11 04:13:06 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.263 2003/02/13 20:45:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "commands/prepare.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
+#include "optimizer/var.h"
#include "parser/analyze.h"
#include "parser/gramparse.h"
#include "parser/parsetree.h"
Assert(length(selectList) == 1);
selectQuery = (Query *) lfirst(selectList);
+ Assert(IsA(selectQuery, Query));
+
+ /*
+ * Check for bogus references to Vars on the current query level
+ * (but upper-level references are okay).
+ * Normally this can't happen because the namespace will be empty,
+ * but it could happen if we are inside a rule.
+ */
+ if (pstate->p_namespace)
+ {
+ if (contain_vars_of_level((Node *) selectQuery, 1))
+ elog(ERROR, "UNION/INTERSECT/EXCEPT member statement may not refer to other relations of same query level");
+ }
/*
* Make the leaf query be a subquery in the top-level rangetable.
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.108 2003/02/13 05:53:46 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.109 2003/02/13 20:45:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static RangeTblRef *
transformRangeSubselect(ParseState *pstate, RangeSubselect *r)
{
- List *save_namespace;
List *parsetrees;
Query *query;
RangeTblEntry *rte;
elog(ERROR, "sub-select in FROM must have an alias");
/*
- * Analyze and transform the subquery. This is a bit tricky because
- * we don't want the subquery to be able to see any FROM items already
- * created in the current query (per SQL92, the scope of a FROM item
- * does not include other FROM items). But it does need to be able to
- * see any further-up parent states, so we can't just pass a null
- * parent pstate link. So, temporarily make the current query level
- * have an empty namespace.
+ * Analyze and transform the subquery.
*/
- save_namespace = pstate->p_namespace;
- pstate->p_namespace = NIL;
-
parsetrees = parse_analyze(r->subquery, pstate);
- pstate->p_namespace = save_namespace;
-
/*
* Check that we got something reasonable. Some of these conditions
* are probably impossible given restrictions of the grammar, but
if (query->resultRelation != 0 || query->into != NULL || query->isPortal)
elog(ERROR, "Subselect in FROM may not have SELECT INTO");
+ /*
+ * The subquery cannot make use of any variables from FROM items created
+ * earlier in the current query. Per SQL92, the scope of a FROM item
+ * does not include other FROM items. Formerly we hacked the namespace
+ * so that the other variables weren't even visible, but it seems more
+ * useful to leave them visible and give a specific error message.
+ *
+ * XXX this will need further work to support SQL99's LATERAL() feature,
+ * wherein such references would indeed be legal.
+ *
+ * We can skip groveling through the subquery if there's not anything
+ * visible in the current query. Also note that outer references are OK.
+ */
+ if (pstate->p_namespace)
+ {
+ if (contain_vars_of_level((Node *) query, 1))
+ elog(ERROR, "Subselect in FROM may not refer to other relations of same query level");
+ }
+
/*
* OK, build an RTE for the subquery.
*/
{
Node *funcexpr;
char *funcname;
- List *save_namespace;
RangeTblEntry *rte;
RangeTblRef *rtr;
funcname = strVal(llast(((FuncCall *) r->funccallnode)->funcname));
/*
- * 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.
+ * Transform the raw FuncCall node.
*/
- 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.)
+ * The function parameters cannot make use of any variables from other
+ * FROM items. (Compare to transformRangeSubselect(); the coding is
+ * different though because we didn't parse as a sub-select with its own
+ * level of namespace.)
+ *
+ * XXX this will need further work to support SQL99's LATERAL() feature,
+ * wherein such references would indeed be legal.
*/
- if (!bms_is_empty(pull_varnos(funcexpr)))
- elog(ERROR, "FROM function expression may not refer to other relations of same query level");
+ if (pstate->p_namespace)
+ {
+ if (contain_vars_of_level(funcexpr, 0))
+ elog(ERROR, "FROM function expression may not refer to other relations of same query level");
+ }
/*
* Disallow aggregate functions in the expression. (No reason to
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