From ca0d2197ca1ed1e72243c5a3466d93e4954d30b0 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 26 Jun 2006 17:24:41 +0000
Subject: Change the row constructor syntax (ROW(...)) so that list elements
 foo.* will be expanded to a list of their member fields, rather than creating
 a nested rowtype field as formerly.  (The old behavior is still available by
 omitting '.*'.)  This syntax is not allowed by the SQL spec AFAICS, so
 changing its behavior doesn't violate the spec.  The new behavior is
 substantially more useful since it allows, for example, triggers to check for
 data changes with 'if row(new.*) is distinct from row(old.*)'.  Per my recent
 proposal.

---
 src/backend/parser/parse_expr.c | 40 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

(limited to 'src/backend/parser/parse_expr.c')

diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 414afe6dfa5..17d221ac19b 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.192 2006/04/22 01:26:00 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.193 2006/06/26 17:24:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -29,6 +29,7 @@
 #include "parser/parse_func.h"
 #include "parser/parse_oper.h"
 #include "parser/parse_relation.h"
+#include "parser/parse_target.h"
 #include "parser/parse_type.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
@@ -1289,6 +1290,43 @@ transformRowExpr(ParseState *pstate, RowExpr *r)
 		Node	   *e = (Node *) lfirst(arg);
 		Node	   *newe;
 
+		/*
+		 * Check for "something.*".  Depending on the complexity of the
+		 * "something", the star could appear as the last name in ColumnRef,
+		 * or as the last indirection item in A_Indirection.
+		 */
+		if (IsA(e, ColumnRef))
+		{
+			ColumnRef  *cref = (ColumnRef *) e;
+
+			if (strcmp(strVal(llast(cref->fields)), "*") == 0)
+			{
+				/* It is something.*, expand into multiple items */
+				newargs = list_concat(newargs,
+									  ExpandColumnRefStar(pstate, cref,
+														  false));
+				continue;
+			}
+		}
+		else if (IsA(e, A_Indirection))
+		{
+			A_Indirection *ind = (A_Indirection *) e;
+			Node	   *lastitem = llast(ind->indirection);
+
+			if (IsA(lastitem, String) &&
+				strcmp(strVal(lastitem), "*") == 0)
+			{
+				/* It is something.*, expand into multiple items */
+				newargs = list_concat(newargs,
+									  ExpandIndirectionStar(pstate, ind,
+															false));
+				continue;
+			}
+		}
+
+		/*
+		 * Not "something.*", so transform as a single expression
+		 */
 		newe = transformExpr(pstate, e);
 		newargs = lappend(newargs, newe);
 	}
-- 
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