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	Sat, 16 May 1998 10:10:07 -0400 (EDT)
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Date: Sat, 16 May 1998 09:10:06 -0500 (CDT)
From: Andy Lewis <alewis@mpsi.net>
To: phd2@earthling.net
cc: pgsql-sql@postgreSQL.org
Subject: Re: [SQL] Duplicate rows
In-Reply-To: <Pine.LNX.3.96.SK.980516175721.21932B-100000@torus.comus.ru>
Message-ID: <Pine.LNX.3.95.980516090952.15079C-100000@shell.mpsi.net>
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Thanks, I'll give it a try.

Andy

On Sat, 16 May 1998, Oleg Broytmann wrote:

>Hi!
>
>On Sat, 16 May 1998, Andy Lewis wrote:
>> Right, I know that there are dups in the column. But, I don't know where they
>> are nor do I know their value(s). I want to be able to find, say, two interger
>> values that are in the same column but, different rows.
>
>   It seems that you need a correlated subquery - a loop for every row, that
>tests whether there are equal values.
>
>SELECT oid, mycolumn FROM mytable a
>   WHERE mycolumn IN
>      (SELECT oid, mycolumn FROM mytable b
>         WHERE a.oid <> b.oid)
>
>Or may be, join with the same table. Not sure what is better in this
>situation.
>
>SELECT oid, mycolumn FROM mytable a, mytable b
>   WHERE a.oid <> b.oid AND
>      a.mycolumn = b.mycolumn
>
>   In both cases "a.oid <> b.oid" excludes the same row from comparison (I
>am pretty sure that in the same row a.mycolumn = b.column :).
>
>Oleg.
>---- 
>  Oleg Broytmann     http://members..tripod.com/~phd2/     phd2@earthling.net
>           Programmers don't die, they just GOSUB without RETURN.
>
>