From: Denis Arh <denis@exonium.net>
To: pgsql-sql@postgresql.org
Subject: Re: Delete duplicates
Date: Mon, 23 Jun 2003 07:16:02 +0200
Message-ID: <00ac01c33946$8d1678e0$0a00000a@neo> (raw)
References: <20030622091522.M37248@oasis.net.au>
<2976.200.59.66.253.1056316636.squirrel@webmail.akyasociados.com.ar>
How to delete "real" duplicates?
id | somthing
-----------------------
1 | aaa
1 | aaa
2 | bbb
2 | bbb
(an accident with backup recovery...)
Regards,
Denis Arh
----- Original Message -----
From: "Franco Bruno Borghesi" <franco@akyasociados.com.ar>
To: <rudi@oasis.net.au>
Cc: <pgsql-sql@postgresql.org>
Sent: Sunday, June 22, 2003 11:17 PM
Subject: Re: [SQL] Delete duplicates
> try this
>
> DELETE FROM aap WHERE id NOT IN (
> SELECT max(id)
> FROM aap
> GROUP BY keyword
> );
>
> >
> >
> > Hi,
> >
> > I have a table with duplicates and trouble with my SQL.
> > I'd like to keep a single record and remove older duplicates.
> > For example below of the 6 recods I'd like to keep records
> > 4 and 6.
> >
> > TABLE: aap
> > id | keyword
> > ----+-----------------
> > 1 | LEAGUE PANTHERS
> > 2 | LEAGUE PANTHERS
> > 3 | LEAGUE PANTHERS
> > 4 | LEAGUE PANTHERS
> > 5 | LEAGUE BRONCOS
> > 6 | LEAGUE BRONCOS
> >
> > Here is my SQL so far, it will select records 1 to 5 instead
> > of 1,2,3 and 5 only.
> >
> > Any help greatly appreciated. I think I need a Group By somewhere in
> > there.
> >
> > select a1.id
> > from aap a1
> > where id < ( SELECT max(id) FROM aap AS a2 )
> > AND EXISTS
> > (
> > SELECT *
> > FROM aap AS a2
> > WHERE a1.keyword = a2.keyword
> > )
> >
> > Regards
> > Rudi.
> >
> > ---------------------------(end of
> > broadcast)--------------------------- TIP 1: subscribe and unsubscribe
> > commands go to majordomo@postgresql.org
>
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 8: explain analyze is your friend
>
>
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To: pgsql-sql@postgresql.org
Cc: denis@exonium.net
Subject: Re: Delete duplicates
In-Reply-To: <00ac01c33946$8d1678e0$0a00000a@neo>
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