From: Stephan Szabo <sszabo@megazone23.bigpanda.com>
To: Abdul Wahab Dahalan <wahab@mimos.my>
Cc: pgsql-sql@postgresql.org
Subject: Re: How to delete duplicate record
Date: Sun, 9 Feb 2003 23:11:52 -0800 (PST)
Message-ID: <20030209231117.H93398-100000@megazone23.bigpanda.com> (raw)
In-Reply-To: <3E4704EA.A7A813CC@mimos.my>
On Mon, 10 Feb 2003, Abdul Wahab Dahalan wrote:
> How do I delete a duplicated records?
> Here I've 7 duplicated records and tried to delete 6 from them.
>
> I tried this query but has error
> b2b=> delete from biztypes where bizid = (select bizid from biztypes
> where bizid = 'B116' limit 6);
> ERROR: More than one tuple returned by a subselect used as an
> expression.
>
> I tried this query, but all records are deleted.
> b2b=> delete from biztypes where bizid = (select bizid from biztypes
> where bizid = 'B116' limit 1);
> DELETE 7
Right, because the subselect ends up being an expensive way of writing the
constant 'B116'. You may want to use a system column like ctid to
differentiate them, maybe:
delete from biztypes where ctid in (select ctid from biztypes where
bizid='B116' limit 6);
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To: pgsql-sql@postgresql.org
Cc: sszabo@megazone23.bigpanda.com, wahab@mimos.my
Subject: Re: How to delete duplicate record
In-Reply-To: <20030209231117.H93398-100000@megazone23.bigpanda.com>
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