From: | "Vincent Hikida" <vhikida(at)inreach(dot)com> |
---|---|
To: | <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: Strange result with select/not null/OR |
Date: | 2003-06-10 02:22:20 |
Message-ID: | 01e801c32ef7$1eb40560$6601a8c0@HOMEOFFICE |
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Thread: | |
Lists: | pgsql-general |
I think that is because if sp_link = '' then sp_link is not null.
There was another thread recently about the null vs ''.
Vincent Hikida,
Member of Technical Staff - Urbana Software, Inc.
"A Personalized Learning Experience"
----- Original Message -----
From: "Fernando Papa" <fpapa(at)claxson(dot)com>
To: <pgsql-general(at)postgresql(dot)org>
Sent: Monday, June 09, 2003 12:48 PM
Subject: [GENERAL] Strange result with select/not null/OR
Hi all!
I get a strange result with this query:
SELECT count(*)
FROM CONT_CAT
WHERE id_instal = 2
and id_cat = 2
and (sp_link IS NOT NULL OR sp_link <> '')
I have one row with an empty value ('') on sp_link, so, when I execute
the query expect 0 on the result.
I don't know why the result is 1.
If I only put the last part ("sp_link <> ''") everithing goes ok.
But I need to check both conditions, IF is null and IF is empty. And I
can't understand why doesn't work.
Any ideas?
Thanks in advance!
--
Fernando O. Papa
DBA
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