To: pgsql-sql@postgresql.org
From: Thomas Kellerer <spam_eater@gmx.net>
Subject: Re: How change col name during query to use it in where clause
Date: Fri, 04 May 2012 15:05:43 +0200
Lines: 19
Message-ID: <jo0k46$qhf$1@dough.gmane.org>
References: <4FA3AEA9.6010401@marcelruff.info>
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In-Reply-To: <4FA3AEA9.6010401@marcelruff.info>

Marcel Ruff, 04.05.2012 12:25:
> Hi,
>
> is an alias name not usable in the where clause?
>
> select EXTRACT(day from enddate::TIMESTAMP - old_enddate::TIMESTAMP) AS TAGE from account_h where TAGE>5;
> ERROR: column "tage" does not exist
> LINE 1: ... TAGE>5 ...

You need to wrap the query:

select *
from (
    select EXTRACT(day from enddate::TIMESTAMP - old_enddate::TIMESTAMP) AS TAGE
    from account_h
) t
where TAGE > 5;