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 07F3A3A4B81
	for <pgsql-sql-postgresql.org@localhost.postgresql.org>;
	Fri, 19 Nov 2004 17:12:48 +0000 (GMT)
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 85132-03
	for <pgsql-sql-postgresql.org@localhost.postgresql.org>;
	Fri, 19 Nov 2004 17:12:41 +0000 (GMT)
Received: from wproxy.gmail.com (wproxy.gmail.com [64.233.184.194])
	by svr1.postgresql.org (Postfix) with ESMTP id B441C3A4B1E
	for <pgsql-sql@postgresql.org>; Fri, 19 Nov 2004 17:12:40 +0000 (GMT)
Received: by wproxy.gmail.com with SMTP id 71so52856wra
	for <pgsql-sql@postgresql.org>; Fri, 19 Nov 2004 09:12:40 -0800 (PST)
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com;
	h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding;
	b=V+NLF8fbmnBoMsHQn9OvGISoNoLmpcuuJ78PBwe+6HuRqtKjUniXh/gIt7/4cyv9AAK07d8nhKPg43Dl+he53ba45ukaF9RsqH6m7VfCFAtMNcuyjs1UGnJ/dnNL8FkNu8+7iVMYkgjKACq+aHW9xnnPo0nlZaev0uphhPMA52c=
Received: by 10.54.41.50 with SMTP id o50mr193624wro;
	Fri, 19 Nov 2004 09:12:39 -0800 (PST)
Received: by 10.54.52.30 with HTTP; Fri, 19 Nov 2004 09:12:38 -0800 (PST)
Message-ID: <6c21003b0411190912630d4afe@mail.gmail.com>
Date: Fri, 19 Nov 2004 11:12:38 -0600
From: Don Drake <dondrake@gmail.com>
Reply-To: Don Drake <dondrake@gmail.com>
To: pgsql-sql@postgresql.org
Subject: NULLS and string concatenation
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
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: 200411/200
X-Sequence-Number: 19519

I have a function that uses an execute statement to insert data into a
table, I do in my implementation of table partitioning.

Anyway, I ran into trouble when NULL values were being passed in
(fields are nullable) and my insert statement turned into a big NULL.

Here's an equivalent statement that caused trouble:

select 'some text, should be null:'|| NULL

This returns NULL and no other text.  Why is that?  I wasn't expecting
the "some text.." to disappear altogether.

Is this a bug?

I was able to work around the problem by using COALESCE (and casting
variables since it wants the same data types passed to it).

-Don

-- 
Donald Drake
President
Drake Consulting
http://www.drakeconsult.com/
312-560-1574