X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 910C3D1B209 for ; Fri, 25 Jun 2004 04:13:23 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 34053-05 for ; Fri, 25 Jun 2004 07:13:18 +0000 (GMT) Received: from rock.spider.ru (rock.spider.ru [62.183.34.226]) by svr1.postgresql.org (Postfix) with ESMTP id 296E9D1B1D9 for ; Fri, 25 Jun 2004 04:13:15 -0300 (ADT) Received: from rock (localhost [127.0.0.1]) by rock (Postfix) with SMTP id 63CCC91386; Fri, 25 Jun 2004 11:13:15 +0400 (MSD) Received: from sad.localnet.ru (sad.localnet.ru [10.0.0.33]) by rock.spider.ru (Postfix) with ESMTP id E97D291258; Fri, 25 Jun 2004 11:13:13 +0400 (MSD) Content-Type: text/plain; charset="iso-8859-1" From: sad Organization: IT To: Rosser Schwarz , pgsql-sql@postgresql.org Subject: Re: feature request ? Date: Fri, 25 Jun 2004 10:20:41 +0400 User-Agent: KMail/1.4.3 References: <200406250816.47781.sad@bankir.ru> <37d451f70406242237dce4a8e@mail.gmail.com> In-Reply-To: <37d451f70406242237dce4a8e@mail.gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Message-Id: <200406251020.41387.sad@bankir.ru> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.0 tagged_above=0.0 required=5.0 tests=LINES_OF_YELLING X-Spam-Level: X-Archive-Number: 200406/251 X-Sequence-Number: 18196 On Friday 25 June 2004 09:37, Rosser Schwarz wrote: > On Fri, 25 Jun 2004 08:16:47 +0400, sad wrote: > > > Very simply, a boolean may have to values: true or false. It's also > > > possible that it's not been set to anything (NULL). > > > > really ? > > what about (13 < NULL)::BOOL > > Per the semantics of NULL, 13 is neither greater than nor less than > NULL. NULL is the *unknown* value; it's impossible to meaningfully > compare it to anything else. Try (NULL =3D NULL)::boolean. It's NULL, > also. READ THE THREAD BEFORE ANSWER