77 *
88 *
99 * IDENTIFICATION
10- * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.20 1998/07/09 14:34:05 thomas Exp $
10+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.21 1998/07/14 03:51:42 thomas Exp $
1111 *
1212 *-------------------------------------------------------------------------
1313 */
@@ -472,7 +472,25 @@ transformUnionClause(List *unionClause, List *targetlist)
472472Oid otype ;
473473otype = ((TargetEntry * )lfirst (prev_target ))-> resdom -> restype ;
474474itype = ((TargetEntry * )lfirst (next_target ))-> resdom -> restype ;
475- if (itype != otype )
475+
476+ #ifdef PARSEDEBUG
477+ printf ("transformUnionClause: types are %d -> %d\n" ,itype ,otype );
478+ #endif
479+
480+ /* one or both is a NULL column? then don't convert... */
481+ if (otype == InvalidOid )
482+ {
483+ /* propagate a known type forward, if available */
484+ if (itype != InvalidOid )
485+ {
486+ ((TargetEntry * )lfirst (prev_target ))-> resdom -> restype = itype ;
487+ }
488+ }
489+ else if (itype == InvalidOid )
490+ {
491+ }
492+ /* they don't match in type? then convert... */
493+ else if (itype != otype )
476494{
477495Node * expr ;
478496
@@ -488,6 +506,7 @@ transformUnionClause(List *unionClause, List *targetlist)
488506((TargetEntry * )lfirst (next_target ))-> expr = expr ;
489507((TargetEntry * )lfirst (next_target ))-> resdom -> restype = otype ;
490508}
509+
491510/* both are UNKNOWN? then evaluate as text... */
492511else if (itype == UNKNOWNOID )
493512{
