diff options
Diffstat (limited to 'src/backend/parser/parse_clause.c')
| -rw-r--r-- | src/backend/parser/parse_clause.c | 95 |
1 files changed, 45 insertions, 50 deletions
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index ec33e5c3090..7893b52f604 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -8,7 +8,7 @@ * * * 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 $ * *------------------------------------------------------------------------- */ @@ -41,8 +41,8 @@ static List *addTargetToSortList(TargetEntry *tle, List *sortlist, 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 @@ -94,32 +94,33 @@ setTargetTable(ParseState *pstate, char *relname) } -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() */ /* @@ -131,7 +132,7 @@ transformWhereClause(ParseState *pstate, Node *clause) { Node *qual; - if (pstate->p_join_quals != NULL) + if (pstate->p_join_quals != NIL) clause = mergeInnerJoinQuals(pstate, clause); if (clause == NULL) @@ -275,21 +276,22 @@ ExpandAttrs(Attr *attr) /* 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 @@ -324,22 +326,11 @@ transformUsingClause(ParseState *pstate, List *usingList, List *leftList, List * 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 @@ -632,7 +623,7 @@ parseFromClause(ParseState *pstate, List *frmList) 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)); @@ -650,7 +641,12 @@ parseFromClause(ParseState *pstate, List *frmList) 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) @@ -660,11 +656,13 @@ parseFromClause(ParseState *pstate, List *frmList) #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) { @@ -682,9 +680,6 @@ parseFromClause(ParseState *pstate, List *frmList) else *qual = (Node *) j->quals; } -#endif - -#if 0 } else { |