Re: FAQ addition: deleteing all but one unique row

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: greg(at)turnstep(dot)com
Cc: pgsql-patches(at)postgresql(dot)org
Subject: Re: FAQ addition: deleteing all but one unique row
Date: 2003-02-10 15:25:36
Message-ID: 5496.1044890736@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-patches

greg(at)turnstep(dot)com writes:
> + <PRE>
> + DELETE FROM mytable WHERE ctid !=
> + (SELECT ctid FROM mytable WHERE id=12 LIMIT 1);
> + </PRE>
> +
> + <P>In the above example, all rows in the table named 'mytable' having a value
> + of 12 in the 'id' column will be deleted except for one.

You haven't actually tested this advice, have you?

The delete as given will delete all but one row, full stop.

Or at least it would if it worked at all. There's no != operator
defined for CTID. (You could get around that with "NOT ctid =".)

regards, tom lane

In response to

Responses

Browse pgsql-patches by date

  From Date Subject
Next Message greg 2003-02-10 15:34:52 Re: FAQ addition: deleteing all but one unique row
Previous Message greg 2003-02-10 15:12:36 FAQ addition: deleteing all but one unique row