X-Original-To: pgsql-sql@postgresql.org Received: from spampd.localdomain (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 0AC86475A45 for ; Sun, 11 May 2003 18:21:52 -0400 (EDT) Received: from secure.tritus.ca (baxter.tritus.ca [209.47.166.15]) by postgresql.org (Postfix) with ESMTP id 703D24758F1 for ; Sun, 11 May 2003 18:21:51 -0400 (EDT) Received: from [10.200.200.129] (CPE00045ae165bc-CM014320108734.cpe.net.cable.rogers.com [::ffff:24.157.7.10]) (AUTH: CRAM-MD5 adam@tritus.ca, TLS: TLSv1/SSLv3, 168bits, DES-CBC3-SHA) by secure.tritus.ca with esmtp; Sun, 11 May 2003 18:21:52 -0400 Date: Sun, 11 May 2003 18:17:54 -0400 From: Adam Sherman To: pgsql-sql@postgresql.org Subject: Constraint Syntax Question Message-ID: <7380000.1052691474@saturn> X-Mailer: Mulberry/3.0.3 (Linux/x86) X-OpenPGP: 82C7 7288 650F 8F77 2FFB C170 3698 125A 79C3 FC80 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Spam-Status: No, hits=-6.6 required=5.0 tests=BAYES_01 version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) X-Archive-Number: 200305/210 X-Sequence-Number: 13375 I have a many-to-many relationship between A & B where a B *must* relate to at least 1 A but an A may have zero Bs. How do add this using an ALTER TABLE statement? Thanks, A. -- Adam Sherman Tritus CG Inc. http://www.tritus.ca/ +1 (613) 797-6819