From: greg@turnstep.com
To: pgsql-sql@postgresql.org
Subject: Re: Count equals 0
Date: Tue, 18 Mar 2003 15:31:47 -0000
Message-ID: <ea0824a43c82b86591e6b913514cf5ba@biglumber.com> (raw)
In-Reply-To: <3E76BCB9.9070603@oasis.net.au>
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> I've tries Left outer join's with and without coalesce without joy so far.
> Please check out my query.
Your query is good, let's just make the whole thing a subselect
and use an outer join to get the missing sites:
SELECT u2.site_name, COALESCE(u1.total, 0)
FROM
(
SELECT site_name, COUNT(cus_id) AS total
FROM user_main um
WHERE NOT EXISTS
(
SELECT cus_id
FROM user_sys_messages usm
WHERE usm.cus_id = um.cus_id
)
GROUP BY site_name
) AS u1
RIGHT OUTER JOIN user_main u2 USING (site_name)
GROUP BY 1,2
ORDER BY u2.site_name;
You could also write this as a LEFT OUTER JOIN (by putting the subselect second),
but I think it is clearer if the USING or ON is as close as possible to the
JOIN statement.
- --
Greg Sabino Mullane greg@turnstep.com
PGP Key: 0x14964AC8 200303181009
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To: pgsql-sql@postgresql.org
Cc: greg@turnstep.com
Subject: Re: Count equals 0
In-Reply-To: <ea0824a43c82b86591e6b913514cf5ba@biglumber.com>
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