Date: Fri, 9 Oct 2009 17:26:20 -0700 (PDT)
From: Stephan Szabo <sszabo@megazone.bigpanda.com>
To: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
Cc: pgsql-sql@postgresql.org
Subject: Re: Existential quantifier
In-Reply-To: <86vdiop1hu.fsf@ds4.des.no>
Message-ID: <20091009172456.C81911@megazone.bigpanda.com>
References: <86bpkgqiv8.fsf@ds4.des.no>
	<20091009160318.J80119@megazone.bigpanda.com>
	<86vdiop1hu.fsf@ds4.des.no>
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On Sat, 10 Oct 2009, [utf-8] Dag-Erling Sm=C3=B8rgrav wrote:

> Stephan Szabo <sszabo@megazone.bigpanda.com> writes:
> > Not at all tested as I don't have access to my db right now, but I thin=
k
> > something like one of these would work:
> >
> > select fs.film.title, fs.film.year
> >  from fs.film
> >  where exists(select 1 from fs.star where fs.film.id =3D fs.star.film
> >   and fs.star.last =3D 'Sheen');
>
> Ah, that was exactly what I was looking for.
>
> > select fs.film.title, fs.film.year
> >  from fs.film
> >  where fs.film.id in (select fs.star.film where fs.star.last =3D 'Sheen=
');
>
> ITYM
>
> select fs.film.title, fs.film.year
>  from fs.film
>  where fs.film.id in (
>    select fs.star.film from fs.star where fs.star.last =3D 'Sheen'
>  );
>
> (missing FROM)

Yeah, that'd be necessary. You might want to try them on a realistic data
set to see how the various options are planned.