Received: from localhost (maia-4.hub.org [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id DD6379FB908
	for <pgsql-sql-postgresql.org@postgresql.org>;
	Tue, 27 Mar 2007 14:42:22 -0300 (ADT)
Received: from postgresql.org ([200.46.204.71])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-new, port 10024)
	with ESMTP id 72042-02-9 for <pgsql-sql-postgresql.org@postgresql.org>;
	Tue, 27 Mar 2007 14:42:22 -0300 (ADT)
X-Greylist: delayed 00:06:38.892566 by SQLgrey-1.7.4
Received: from rrr1-v3.mail.re4.yahoo.com (rrr1-v3.mail.re4.yahoo.com
	[216.39.53.4]) by postgresql.org (Postfix) with SMTP id 4827C9FB890
	for <pgsql-sql@postgresql.org>; Tue, 27 Mar 2007 14:42:21 -0300 (ADT)
Received: (qmail 42904 invoked from network); 27 Mar 2007 17:35:40 -0000
Received: from web54310.mail.yahoo.com (206.190.49.120)
	by rrr1-v3.mail.re4.yahoo.com with SMTP; 27 Mar 2007 17:35:40 -0000
Received: (qmail 67803 invoked by uid 60001); 27 Mar 2007 17:35:37 -0000
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com;
	h=X-YMail-OSG:Received:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID;
	b=LmtUKzW3dwlU9a4JbBgNA8+IaBdvxcEMzbtSDB/Ocqg34ryMG+K/i94/LonFpaAsjV3Hh57idbv9bA8ohfhDfCfGzqBoWbmpEHU+BqtPd11Me+yKQt8tukex16SE6N0iHprwvb5YypRInSTrp1p4kMenKAwA/IZMHmNavfWKxwI=;
X-YMail-OSG: 
 _EfX0WUVM1mvqT2AAyBqRZmTUsmO7RUuTGN_Ib7ha3LgLHhh10BMt1s66645bYn7N7sEmBFFK4xym1lldwb7Y_X_k_CIWhhOV3uj2YSG9mrS9wf.rbrsEDE1WWhhEA--
Received: from [24.10.123.39] by web54310.mail.yahoo.com via HTTP;
	Tue, 27 Mar 2007 10:35:37 PDT
Date: Tue, 27 Mar 2007 10:35:37 -0700 (PDT)
From: chester c young <chestercyoung@yahoo.com>
Subject: Re: Foreign Unique Constraint
To: Jon Horsman <horshaq@gmail.com>
Cc: sql pgsql <pgsql-sql@postgresql.org>
In-Reply-To: <4f4c2a010703270621h5137a4e5rb515a9be9034a543@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
Message-ID: <415536.67726.qm@web54310.mail.yahoo.com>
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200703/322
X-Sequence-Number: 27960


> 
> create table table1 (
> id SERIAL PRIMARY KEY
> extension UNIQUE,
> <other fields>
> )
> 
> create table table2 (
> id SERIAL PRIMARY KEY
> extension UNIQUE,
> <different fields>
> )
> 
> Basically table 1 and table 2 both have the concept of an extension
> that must be unique but the rest of the info in the tables are
> different.  I need to ensure that if i add an entry to table 1 with
> extension 1000 that it will fail if there is already an entry in
> table2 with the same extension.

use a pre-insert triggers - one for each table.  include something like

if exists( select 1 from table2 where extension=new.extension ) then
  raise exception ...
end if;




 
____________________________________________________________________________________
Expecting? Get great news right away with email Auto-Check. 
Try the Yahoo! Mail Beta.
http://advision.webevents.yahoo.com/mailbeta/newmail_tools.html