From: Robert Treat <xzilla@users.sourceforge.net>
To: Josh Berkus <josh@agliodbs.com>
To: Stephan Szabo <sszabo@megazone23.bigpanda.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: help with "delete joins"
Date: 01 Jul 2003 09:43:07 -0400
Message-ID: <1057066987.24310.383.camel@camel> (raw)
In-Reply-To: <200306301735.29482.josh@agliodbs.com>
References: <1057011998.24310.348.camel@camel>
<200306301735.29482.josh@agliodbs.com>
On Mon, 2003-06-30 at 20:35, Josh Berkus wrote:
> Robert,
>
> > delete * from foo where not (foo.a = bar.a and foo.b=bar.b and
> > foo.c=bar.c) ;
> >
> > so i end up with
> >
> > postgres=# select * from foo;
> > a | b | c | d
> > ---+---+---+---
> > 1 | 2 | 4 | A
> > 4 | 5 | 6 | b
> > (2 rows)
> >
> > but thats not valid sql, is there some way to accomplish this?
>
> Um, your example result doesn't match your pseudo-query.
the end of a long day that started with 4 hours of sleep... no wonder I
couldn't get my head around this one. I actually did want the results of
the psuedo query, not the results I posted :-\
> Assuming that you
> want to delete everything that DOES match, not everything that DOESN'T, do:
>
> DELETE FROM foo
> WHERE EXISTS ( SELECT bar.a FROM bar
> WHERE bar.a = foo.a AND bar.b = foo.b
> AND bar.c = foo.c );
I was almost there with my original query... a NOT on your/stephan's
query gets me what I really want. :-) Thanks guys.
Robert Treat
--
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL
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To: pgsql-sql@postgresql.org
Cc: xzilla@users.sourceforge.net, josh@agliodbs.com, sszabo@megazone23.bigpanda.com
Subject: Re: help with "delete joins"
In-Reply-To: <1057066987.24310.383.camel@camel>
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