Received: from maia.hub.org (unknown [200.46.204.183])
	by mail.postgresql.org (Postfix) with ESMTP id 245A2632F1A
	for <pgsql-sql-postgresql.org@mail.postgresql.org>;
	Fri,  9 Oct 2009 20:48:39 -0300 (ADT)
Received: from mail.postgresql.org ([200.46.204.86])
	by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia,
	port 10024) with ESMTP id 76779-10 for
	<pgsql-sql-postgresql.org@mail.postgresql.org>;
	Fri,  9 Oct 2009 23:48:30 +0000 (UTC)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from tim.des.no (tim.des.no [194.63.250.121])
	by mail.postgresql.org (Postfix) with ESMTP id 11C02632DBA
	for <pgsql-sql@postgresql.org>; Fri,  9 Oct 2009 20:48:31 -0300 (ADT)
Received: from ds4.des.no (des.no [84.49.246.2])
	by smtp.des.no (Postfix) with ESMTP id 2C2EE6D41B;
	Fri,  9 Oct 2009 23:48:28 +0000 (UTC)
Received: by ds4.des.no (Postfix, from userid 1001)
	id CDB4484503; Sat, 10 Oct 2009 01:48:27 +0200 (CEST)
From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Richard Albright <ralbright@insiderscore.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Existential quantifier
References: <86bpkgqiv8.fsf@ds4.des.no>
	<1255129869.11289.4.camel@indie-desktop>
Date: Sat, 10 Oct 2009 01:48:27 +0200
In-Reply-To: <1255129869.11289.4.camel@indie-desktop> (Richard Albright's
	message of "Fri, 09 Oct 2009 19:11:09 -0400")
Message-ID: <86zl80p1ro.fsf@ds4.des.no>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.95 (berkeley-unix)
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=-2.599 tagged_above=-10 required=5
	tests=BAYES_00=-2.599
X-Spam-Level: 
X-Archive-Number: 200910/37
X-Sequence-Number: 33236

Richard Albright <ralbright@insiderscore.com> writes:
> you could use distinct on
>
> select distinct on (fs.film.title, fs.film.year ) title, year
> from fs.film left join fs.star on fs.film.id =3D fs.star.film
>   where fs.star.last =3D 'Sheen';

Thanks, I didn't know about "distinct on".  This version uses the
primary (surrogage) key:

select distinct on (fs.film.id) fs.film.title, fs.film.year
  from fs.film left join fs.star on fs.film.id =3D fs.star.film
  where fs.star.last =3D 'Sheen';

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no