From 499c81d3a3ffef4645b720ace5909f00609bff79 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 4 Jul 2001 17:36:54 +0000
Subject: [PATCH] Prohibit a column from appearing twice in a PRIMARY KEY or
 UNIQUE constraint.  This case (a) is useless, (b) violates SQL92, and (c) is
 certain to cause a failure downstream when we try to create an index with
 duplicated column names.  So give an appropriate error message instead of
 letting the index failure occur.  Per report from Colin Strickland.  NOTE:
 currently, CREATE INDEX fooi ON foo(f1,f1) still fails with 'cannot insert
 duplicate key' error.  Should we change that too?  What about functional
 indexes?

---
 src/backend/parser/analyze.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index fc03173ce3..9d6dfeb69a 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.191 2001/06/25 21:11:44 tgl Exp $
+ *	$Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.192 2001/07/04 17:36:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -954,8 +954,8 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
 
 		index = makeNode(IndexStmt);
 
-		index->unique = TRUE;
-		index->primary = (constraint->contype == CONSTR_PRIMARY ? TRUE : FALSE);
+		index->unique = true;
+		index->primary = (constraint->contype == CONSTR_PRIMARY);
 		if (index->primary)
 		{
 			if (pkey != NULL)
@@ -1057,6 +1057,17 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
 				elog(ERROR, "CREATE TABLE: column \"%s\" named in key does not exist",
 					 key->name);
 
+			/* Check for PRIMARY KEY(foo, foo) */
+			foreach(columns, index->indexParams)
+			{
+				iparam = (IndexElem *) lfirst(columns);
+				if (strcmp(key->name, iparam->name) == 0)
+					elog(ERROR, "CREATE TABLE: column \"%s\" appears twice in %s constraint",
+						 key->name,
+						 index->primary ? "PRIMARY KEY" : "UNIQUE");
+			}
+
+			/* OK, add it to the index definition */
 			iparam = makeNode(IndexElem);
 			iparam->name = pstrdup(key->name);
 			iparam->args = NIL;