Received: from maia.hub.org (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id DD284632FB3 for ; Thu, 18 Mar 2010 12:11:26 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 23391-08 for ; Thu, 18 Mar 2010 15:11:16 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by mail.postgresql.org (Postfix) with ESMTP id 45BCF632A17 for ; Thu, 18 Mar 2010 12:11:16 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id o2IFBDkJ011075; Thu, 18 Mar 2010 11:11:14 -0400 (EDT) To: Mark Fenbers cc: pgsql-sql@postgresql.org Subject: Re: Simple aggregate query brain fart In-reply-to: <4BA24184.7060603@noaa.gov> References: <62e0109f1003162359l65b6961ercd14b687433a9ff3@mail.gmail.com> <20100317071335.GC25571@a-kretschmer.de> <62e0109f1003170130q7a86d8afidf6159dcbd35ade@mail.gmail.com> <62e0109f1003170525m6e187b32n58850bd48259daa8@mail.gmail.com> <27653.1268835046@sss.pgh.pa.us> <4BA24184.7060603@noaa.gov> Comments: In-reply-to Mark Fenbers message dated "Thu, 18 Mar 2010 11:06:44 -0400" Date: Thu, 18 Mar 2010 11:11:13 -0400 Message-ID: <11074.1268925073@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.599 tagged_above=-10 required=5 tests=BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 201003/147 X-Sequence-Number: 33854 Mark Fenbers writes: > I want to do: > SELECT id, count(*) FROM mytable WHERE count(*) > 2 GROUP BY id; > But this doesn't work because Pg won't allow aggregate functions in a > where clause. Use HAVING, not WHERE. The way you are trying to write the query is meaningless because WHERE filters rows before grouping/aggregation. HAVING filters afterwards, which is when it makes sense to put a condition on count(*). regards, tom lane