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From: Aaron Bono <postgresql@aranya.com>
To: James Cloos <cloos@jhcloos.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: where clause subqueries vs multiple rows results
Date: Sun, 10 Sep 2006 23:54:25 -0500
Message-ID: <bf05e51c0609102154uebc2bc5kebe34b10520d351c@mail.gmail.com> (raw)
In-Reply-To: <m3y7srm695.fsf@lugabout.jhcloos.org>
References: <m3y7srm695.fsf@lugabout.jhcloos.org>

On 9/10/06, James Cloos <cloos@jhcloos.com> wrote:
>
> I've a query which I'd have liked to word akin to:
>
>   SELECT guid FROM child WHERE the_fkey =
>          ( SELECT id FROM parent WHERE name ~ 'some_regex' )
>          ORDER BY the_fkey, my_pkey;
>
> I got around it by doing the SELECT id first, and then doing a SELECT
> guid for each row returned, appending the results together.
>
> Can that be done in a single query, insead of 1+n queries?



Will this work?

SELECT guid
FROM child
INNER JOIN parent ON (
    child.the_fkey = parent.id
    AND
)
WHERE name ~ 'some_regex'
ORDER BY
    child.the_fkey,
    child.my_pkey
;

I am not sure what table name is from but since you say it is n+1 queries I
assume it is from the child table?  It would help to know what columns are
on which tables.

==================================================================
   Aaron Bono
   Aranya Software Technologies, Inc.
   http://www.aranya.com
   http://codeelixir.com
==================================================================

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  Subject: Re: where clause subqueries vs multiple rows results
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