From: | Martín Marqués <martin(dot)marques(at)gmail(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | NOT IN vs. OUTER JOIN and NOT NULL |
Date: | 2010-09-09 11:59:00 |
Message-ID: | AANLkTink6EN+OwmPwAPZWHb-Ogk22vQS8fJAVPK_JhDm@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
I was looking at rows in a table which are not referenced from another
and found some discrepencies.
These are the queries (with results):
SELECT * from grupo_concursantes where codigo NOT IN (SELECT grupo
FROM concursantes);
codigo | numero | evento | escuela
--------+--------+--------+---------
(0 filas)
SELECT g.* FROM grupo_concursantes g left outer join concursantes c on
(g.codigo=c.grupo)
where c.codigo IS NULL;
codigo | numero | evento | escuela
--------+--------+--------+---------
25 | 1 | 1 | 69331
33 | 2 | 1 | 60233
53 | 2 | 1 | 60490
64 | 6 | 1 | 68861
73 | 1 | 1 | 69220
(5 filas)
Why aren't the 5 rows from the second query in the first?
--
Martín Marqués
select 'martin.marques' || '@' || 'gmail.com'
DBA, Programador, Administrador
From | Date | Subject | |
---|---|---|---|
Next Message | Thom Brown | 2010-09-09 12:13:37 | Re: NOT IN vs. OUTER JOIN and NOT NULL |
Previous Message | Phui Hock | 2010-09-09 11:13:09 | How to inherit search_path from template |