Received: from localhost (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 9040A476375 for ; Tue, 26 Nov 2002 10:45:04 -0500 (EST) Received: from anchor-post-39.mail.demon.net (anchor-post-39.mail.demon.net [194.217.242.80]) by postgresql.org (Postfix) with ESMTP id 80F02476296 for ; Tue, 26 Nov 2002 10:45:03 -0500 (EST) Received: from mwynhau.demon.co.uk ([193.237.186.96] helo=mainbox.archonet.com) by anchor-post-39.mail.demon.net with esmtp (Exim 3.36 #2) id 18Ghtb-0003zd-0U; Tue, 26 Nov 2002 15:45:07 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by mainbox.archonet.com (Postfix) with ESMTP id A018317508; Tue, 26 Nov 2002 15:37:01 +0000 (GMT) Received: from client.archonet.com (client.archonet.com [192.168.1.16]) by mainbox.archonet.com (Postfix) with ESMTP id D2DE8174ED; Tue, 26 Nov 2002 15:37:00 +0000 (GMT) Content-Type: text/plain; charset="iso-8859-7" From: Richard Huxton Organization: Archonet Ltd To: "Giannis" , Subject: Re: SQL -select count- Date: Tue, 26 Nov 2002 15:36:58 +0000 User-Agent: KMail/1.4.3 References: <00cf01c28fee$144d8bd0$dd4186c3@edunet.uoa.gr> In-Reply-To: <00cf01c28fee$144d8bd0$dd4186c3@edunet.uoa.gr> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Message-Id: <200211261536.58303.dev@archonet.com> X-Virus-Scanned: by AMaViS snapshot-20020531 X-Virus-Scanned: by AMaViS new-20020517 X-Archive-Number: 200211/393 X-Sequence-Number: 10535 On Tuesday 19 Nov 2002 5:06 pm, Giannis wrote: > when I do : > > select count(column_name) from table_name > > should I get the count for all columns or just those which are not null? Just "not null" - use count(*) or count(0) for a count of rows. --=20 Richard Huxton