Re: Strange result with select/not null/OR
От | Vincent Hikida |
---|---|
Тема | Re: Strange result with select/not null/OR |
Дата | |
Msg-id | 01e801c32ef7$1eb40560$6601a8c0@HOMEOFFICE обсуждение исходный текст |
Ответ на | Strange result with select/not null/OR ("Fernando Papa" <fpapa@claxson.com>) |
Список | 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" www.UrbanaSoft.com ----- Original Message ----- From: "Fernando Papa" <fpapa@claxson.com> To: <pgsql-general@postgresql.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 ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
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