From: PFC <lists@boutiquenumerique.com>
To: zeus@ix.netcom.com
To: pgsql-sql@postgresql.org
Subject: Re: "How do I ..." SQL question
Date: Tue, 18 Jan 2005 01:13:13 +0100
Message-ID: <opskruwbvwth1vuj@musicbox> (raw)
In-Reply-To: <31958303.1106004700938.JavaMail.root@dewey.psp.pas.earthlink.net>
References: <31958303.1106004700938.JavaMail.root@dewey.psp.pas.earthlink.net>
Return only four rows beginning at second row:
>
> SELECT count(*) AS count, name, year FROM a
> GROUP BY name, year
> ORDER BY count DESC, name ASC
> LIMIT 4 OFFSET 1;
>
> count name year
> ------- ------ ------
> 3 joe 2004 s,e,e
> 2 bob 2003 w,e
> 2 kim 2003 s,s
> 2 sue 2004 s,w
>
> Select only places visited included in LIMITed query:
Is this :
SELECT DISTINCT place FROM a,(
SELECT count(*) AS count, name, year FROM a
GROUP BY name, year
ORDER BY count DESC, name ASC
LIMIT 4 OFFSET 1
) as foo WHERE name=foo.name AND year=foo.year
Problem with this approach is that you'll have to run the query twice,
one to get the hitlist by user, one for the places...
>
> SELECT DISTINCT place FROM a ????;
>
> place
> -------
> south
> west
> east
>
> Note that the place north does not appear in the last result
> because north was only visited by bob in 2005 and kim in 2004,
> records which are not included in the limited result.
>
> Any help appreciated.
>
> -Bob
>
> ---------------------------(end of broadcast)---------------------------
> TIP 8: explain analyze is your friend
>
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To: pgsql-sql@postgresql.org
Cc: lists@boutiquenumerique.com, zeus@ix.netcom.com
Subject: Re: "How do I ..." SQL question
In-Reply-To: <opskruwbvwth1vuj@musicbox>
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