Message-ID: <00ac01c33946$8d1678e0$0a00000a@neo>
From: "Denis Arh" <denis@exonium.net>
To: <pgsql-sql@postgresql.org>
References: <20030622091522.M37248@oasis.net.au>
	<2976.200.59.66.253.1056316636.squirrel@webmail.akyasociados.com.ar>
Subject: Re: Delete duplicates
Date: Mon, 23 Jun 2003 07:16:02 +0200
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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
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> 
> 
> 
> 
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