*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.59 2000/04/12 17:15:26 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.60 2000/05/12 01:33:54 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static bool exprIsInSortList(Node *expr, List *sortList, List *targetList);
#ifndef DISABLE_OUTER_JOINS
-static Node *transformUsingClause(ParseState *pstate, List *using, List *left, List *right);
-
+static List *transformUsingClause(ParseState *pstate, List *using,
+ List *left, List *right);
#endif
}
-Node *
- mergeInnerJoinQuals(ParseState *pstate, Node *clause);
-
-Node *
+static Node *
mergeInnerJoinQuals(ParseState *pstate, Node *clause)
{
- A_Expr *expr = (A_Expr *) pstate->p_join_quals;
+ List *jquals;
- if (expr == NULL)
- return clause;
-
- if (clause != NULL)
+ foreach(jquals, pstate->p_join_quals)
{
- A_Expr *a = makeNode(A_Expr);
+ Node *jqual = (Node *) lfirst(jquals);
+
+ if (clause == NULL)
+ clause = jqual;
+ else
+ {
+ A_Expr *a = makeNode(A_Expr);
- a->oper = AND;
- a->opname = NULL;
- a->lexpr = (Node *) expr;
- a->rexpr = clause;
- expr = a;
+ a->oper = AND;
+ a->opname = NULL;
+ a->lexpr = clause;
+ a->rexpr = jqual;
+ clause = (Node *) a;
+ }
}
- /* Make sure that we don't do this twice... */
- pstate->p_join_quals = NULL;
+ /* Make sure that we don't add same quals twice... */
+ pstate->p_join_quals = NIL;
- return (Node *) expr;
+ return clause;
} /* mergeInnerJoinQuals() */
/*
{
Node *qual;
- if (pstate->p_join_quals != NULL)
+ if (pstate->p_join_quals != NIL)
clause = mergeInnerJoinQuals(pstate, clause);
if (clause == NULL)
/* transformUsingClause()
* Take an ON or USING clause from a join expression and expand if necessary.
+ * Result is an implicitly-ANDed list of untransformed qualification clauses.
*/
-static Node *
-transformUsingClause(ParseState *pstate, List *usingList, List *leftList, List *rightList)
+static List *
+transformUsingClause(ParseState *pstate, List *usingList,
+ List *leftList, List *rightList)
{
- A_Expr *expr = NULL;
+ List *result = NIL;
List *using;
foreach(using, usingList)
{
- List *col;
- A_Expr *e;
-
Attr *uattr = lfirst(using);
Attr *lattr = NULL,
*rattr = NULL;
+ List *col;
+ A_Expr *e;
/*
* find the first instances of this column in the shape list and
e->lexpr = (Node *) lattr;
e->rexpr = (Node *) rattr;
- if (expr != NULL)
- {
- A_Expr *a = makeNode(A_Expr);
-
- a->oper = AND;
- a->opname = NULL;
- a->lexpr = (Node *) expr;
- a->rexpr = (Node *) e;
- expr = a;
- }
- else
- expr = e;
+ result = lappend(result, e);
}
- return ((Node *) transformExpr(pstate, (Node *) expr, EXPR_COLUMN_FIRST));
-} /* transformUsiongClause() */
+ return result;
+} /* transformUsingClause() */
#endif
printf("JOIN/USING input quals are %s\n", nodeToString(j->quals));
- j->quals = (List *) transformUsingClause(pstate, shape, l_cols, r_cols);
+ j->quals = transformUsingClause(pstate, shape, l_cols, r_cols);
printf("JOIN/USING transformed quals are %s\n", nodeToString(j->quals));
else
j->quals = (List *) lcons(j->quals, NIL);
- pstate->p_join_quals = (Node *) j->quals;
+ /* listCopy may not be needed here --- will j->quals list
+ * be used again anywhere? The #ifdef'd code below may need
+ * it, if it ever gets used...
+ */
+ pstate->p_join_quals = nconc(pstate->p_join_quals,
+ listCopy(j->quals));
#if 0
if (qual == NULL)
#endif
#if 0
+ /* XXX this code is WRONG because j->quals is a List
+ * not a simple expression. Perhaps *qual
+ * ought also to be a List and we append to it,
+ * similarly to the way p_join_quals is handled above?
+ */
if (*qual == NULL)
{
-#endif
-
-#if 0
/* merge qualified join clauses... */
if (j->quals != NULL)
{
else
*qual = (Node *) j->quals;
}
-#endif
-
-#if 0
}
else
{
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: parse_node.h,v 1.19 2000/04/12 17:16:45 momjian Exp $
+ * $Id: parse_node.h,v 1.20 2000/05/12 01:33:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "utils/rel.h"
/* State information used during parse analysis
- * p_join_quals is a list of qualification expressions
- * found in the FROM clause. Needs to be available later
- * to merge with other qualifiers from the WHERE clause.
+ * p_join_quals is a list of untransformed qualification expressions
+ * (implicitly ANDed together) found in the FROM clause.
+ * Needs to be available later to merge with other qualifiers from the
+ * WHERE clause.
*/
typedef struct ParseState
{
RangeTblEntry *p_target_rangetblentry;
List *p_shape;
List *p_alias;
- Node *p_join_quals;
+ List *p_join_quals;
} ParseState;
extern ParseState *make_parsestate(ParseState *parentParseState);
--
SELECT '' AS "xxx", *
FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i = J2_TBL.i);
-ERROR: transformExpr: does not know how to transform node 501 (internal error)
+ xxx | i | j | t | i | k
+-----+---+---+-------+---+----
+ | 1 | 3 | one | 1 | -1
+ | 2 | 2 | two | 2 | 2
+ | 2 | 2 | two | 2 | 4
+ | 3 | 1 | three | 3 | -3
+(4 rows)
+
SELECT '' AS "xxx", *
FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i = J2_TBL.k);
-ERROR: transformExpr: does not know how to transform node 501 (internal error)
+ xxx | i | j | t | i | k
+-----+---+---+------+---+---
+ | 2 | 2 | two | 2 | 2
+ | 4 | 0 | four | 2 | 4
+(2 rows)
+
SELECT '' AS "xxx", *
FROM J1_TBL CROSS JOIN J2_TBL;
xxx | i | j | t | i | k
--
SELECT '' AS "xxx", *
FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i <= J2_TBL.k);
-ERROR: transformExpr: does not know how to transform node 501 (internal error)
+ xxx | i | j | t | i | k
+-----+---+---+-------+---+---
+ | 1 | 3 | one | 2 | 2
+ | 2 | 2 | two | 2 | 2
+ | 1 | 3 | one | 2 | 4
+ | 2 | 2 | two | 2 | 4
+ | 3 | 1 | three | 2 | 4
+ | 4 | 0 | four | 2 | 4
+(6 rows)
+
--
-- Outer joins
--
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