Date: Wed, 28 Mar 2007 16:24:44 +0200
From: "A. Kretschmer" <andreas.kretschmer@schollglas.com>
To: pgsql-sql@postgresql.org
Subject: Re: union with count?
Message-ID: <20070328142444.GA20168@a-kretschmer.de>
References: <460A75ED.6070501@fmed.uba.ar>
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am  Wed, dem 28.03.2007, um 11:04:29 -0300 mailte Gerardo Herzig folgendes:
> Hi dudes, i have the following question
> i have 2 tables with the same format, and i want to know if is there a 
> possibility of using some sort of count(*) for achieving this result:
> select a from table1 where (condition) union select a from table2 where 
> (condition), count(a) group by a
> 
> The idea is having how many times (condition) is true for both tables.
> 
> Im not shure im explaining myself clearly, my english is not the best 
> (as you can see ;)

You can use a subselect, a simple example:

test=# select *, count(1) from (select 1 union select 2 union select 3) foo group by 1;
 ?column? | count
----------+-------
        1 |     1
        2 |     1
        3 |     1
(3 rows)


Andreas
-- 
Andreas Kretschmer
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