Use variable aliases, if supplied, rather than real column names in

complaints about ungrouped variables.  This is for consistency with
behavior elsewhere, notably the fact that the relname is reported as
an alias in these same complaints.  Also, it'll work with subselect-
in-FROM where old code didn't.

src/include/parser/parsetree.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsetree.h,v 1.11 2000/09/12 21:07:12 tgl Exp $
+ * $Id: parsetree.h,v 1.12 2000/09/25 18:14:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,12 +16,8 @@
 #define PARSETREE_H
 
 #include "nodes/parsenodes.h"
-#include "nodes/pg_list.h"
+#include "nodes/pg_list.h"		/* for nth(), etc */
 
-/* ----------------
- *		need pg_list.h for definitions of nth(), etc.
- * ----------------
- */
 
 /* ----------------
  *		range table macros
@@ -33,10 +29,9 @@
  *		rt_store
  *
  *		Access and (destructively) replace rangetable entries.
- *
  */
 #define rt_fetch(rangetable_index, rangetable) \
-	((RangeTblEntry*) nth((rangetable_index)-1, rangetable))
+	((RangeTblEntry *) nth((rangetable_index)-1, rangetable))
 
 #define rt_store(rangetable_index, rangetable, rt) \
 	set_nth(rangetable, (rangetable_index)-1, rt)
@@ -45,9 +40,16 @@
  *		getrelid
  *
  *		Given the range index of a relation, return the corresponding
- *		relation OID.
+ *		relation OID.  Note that InvalidOid will be returned if the
+ *		RTE is for a sub-select rather than a relation.
  */
 #define getrelid(rangeindex,rangetable) \
 	(rt_fetch(rangeindex, rangetable)->relid)
 
+/*
+ * Given an RTE and an attribute number, return the appropriate
+ * variable name or alias for that attribute of that RTE.
+ */
+extern char *get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum);
+
 #endif	 /* PARSETREE_H */