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 DCBEDD1B1AA for ; Tue, 29 Jun 2004 14:47:17 -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 17155-02 for ; Tue, 29 Jun 2004 17:47:17 +0000 (GMT) Received: from megazone.bigpanda.com (megazone.bigpanda.com [64.147.171.210]) by svr1.postgresql.org (Postfix) with ESMTP id F04C7D1B1D2 for ; Tue, 29 Jun 2004 14:47:14 -0300 (ADT) Received: by megazone.bigpanda.com (Postfix, from userid 1001) id 5BD6A356AD; Tue, 29 Jun 2004 10:46:03 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by megazone.bigpanda.com (Postfix) with ESMTP id 5A4D6356AA; Tue, 29 Jun 2004 10:46:03 -0700 (PDT) Date: Tue, 29 Jun 2004 10:46:03 -0700 (PDT) From: Stephan Szabo To: Greg Stark Cc: Stefan Weiss , pgsql-sql@postgresql.org Subject: Re: FW: "=" operator vs. "IS" In-Reply-To: <873c4ez2u4.fsf@stark.xeocode.com> Message-ID: <20040629104400.M63066@megazone.bigpanda.com> References: <7A4ADADFC8AFF0478D47F63BEDD57CE33A320C@gpmail.gphq.genpathpharma.com> <200406290102.24885.spaceman@foo.at> <20040628161747.C38283@megazone.bigpanda.com> <873c4ez2u4.fsf@stark.xeocode.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.0 tagged_above=0.0 required=5.0 tests= X-Spam-Level: X-Archive-Number: 200406/297 X-Sequence-Number: 18242 On Tue, 29 Jun 2004, Greg Stark wrote: > Stephan Szabo writes: > > > IS TRUE and IS FALSE have a different effect from =true and =false when > > the left hand side is NULL. The former will return false, the latter will > > return NULL. > > No, actually they both return false. For purposes of anyone reading this in the archives I'd meant NULL IS TRUE and NULL IS FALSE return false vs NULL=true and NULL=false returning NULL.