From 2337780e0e17a9d7e7caf72a69440e1e6c7abe4b Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 26 Nov 2001 21:15:14 +0000
Subject: [PATCH] Change display of FieldSelect nodes from arg.field to
 field(arg), per bug report from Stefan Hadjistoytchev.  There are some cases
 where the dot notation works, but there are more where it doesn't. Eventually
 ought to consider fixing the parser to allow cases like func().field, but for
 now this is the simplest patch.

---
 src/backend/utils/adt/ruleutils.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 421c6a828c..27abf6ace5 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -3,7 +3,7 @@
  *				back to source text
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.88 2001/11/26 00:29:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.89 2001/11/26 21:15:14 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1866,28 +1866,36 @@ get_rule_expr(Node *node, deparse_context *context)
 		case T_FieldSelect:
 			{
 				FieldSelect *fselect = (FieldSelect *) node;
+				Oid			argType = exprType(fselect->arg);
 				HeapTuple	typetup;
 				Form_pg_type typeStruct;
 				Oid			typrelid;
 				char	   *fieldname;
 
-				/* we do NOT parenthesize the arg expression, for now */
-				get_rule_expr(fselect->arg, context);
+				/* lookup arg type and get the field name */
 				typetup = SearchSysCache(TYPEOID,
-								ObjectIdGetDatum(exprType(fselect->arg)),
+										 ObjectIdGetDatum(argType),
 										 0, 0, 0);
 				if (!HeapTupleIsValid(typetup))
 					elog(ERROR, "cache lookup of type %u failed",
-						 exprType(fselect->arg));
+						 argType);
 				typeStruct = (Form_pg_type) GETSTRUCT(typetup);
 				typrelid = typeStruct->typrelid;
 				if (!OidIsValid(typrelid))
 					elog(ERROR, "Argument type %s of FieldSelect is not a tuple type",
-						 NameStr(typeStruct->typname));
+						 format_type_be(argType));
+				ReleaseSysCache(typetup);
 				fieldname = get_relid_attribute_name(typrelid,
 													 fselect->fieldnum);
-				appendStringInfo(buf, ".%s", quote_identifier(fieldname));
-				ReleaseSysCache(typetup);
+				/*
+				 * If the argument is simple enough, we could emit
+				 * arg.fieldname, but most cases where FieldSelect is used
+				 * are *not* simple.  For now, always use the projection-
+				 * function syntax.
+				 */
+				appendStringInfo(buf, "%s(", quote_identifier(fieldname));
+				get_rule_expr(fselect->arg, context);
+				appendStringInfoChar(buf, ')');
 			}
 			break;
 
-- 
2.11.0