From: Andreas Gaab <A.Gaab@scanlab.de>
To: '8q5tmkyqry@sneakemail.com' <8q5tmkyqry@sneakemail.com>
To: pgsql-sql@postgresql.org <pgsql-sql@postgresql.org>
Subject: Re: selecting rows tagged with "a" but not "b"
Date: Mon, 1 Feb 2010 14:50:44 +0100
Message-ID: <48DA836F3865C54B8FBF424A3B775AF6F8ED2A6D@Exchange-Server.scanlab-intern.de> (raw)
In-Reply-To: <11366-1265031099-334353@sneakemail.com>
References: <11366-1265031099-334353@sneakemail.com>
Hi Darrell,
SELECT DISTINCT articleID FROM tags WHERE tag = "a"
EXCEPT
SELECT DISTINCT articleID FROM tags WHERE tag = "b";
Regards,
Andreas
-----Ursprüngliche Nachricht-----
Von: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org] Im Auftrag von 8q5tmkyqry@sneakemail.com
Gesendet: Montag, 1. Februar 2010 14:32
An: pgsql-sql@postgresql.org
Betreff: [SQL] selecting rows tagged with "a" but not "b"
Hi,
I have a two tables:
article
articleID, name, content
tags
articleID, tag
I want to find all articles that are tagged with "a" but not "b"
how do I do this?
what I'd like to do is:
<wishful thinking>
select articleID from tags where tag="a"
SUBTRACT
select articleID from tags where tab="b"
</wishful thinking>
how do I do this in real SQL?
thanks
Darrell
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Cc: A.Gaab@scanlab.de, 8q5tmkyqry@sneakemail.com
Subject: Re: selecting rows tagged with "a" but not "b"
In-Reply-To: <48DA836F3865C54B8FBF424A3B775AF6F8ED2A6D@Exchange-Server.scanlab-intern.de>
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