2007/10/12, Clemens Schwaighofer <cs@xxxxxxxxxxxxx>:
> hi,
>
> thats the first time I am a bit confused by a query not working.
>
> I have this table:
>
> gullevek=# \d test
> Table "public.test"
> Column | Type | Modifiers
> ---------+-------------------+--------------------------------------------------------
> test_id | integer | not null default
> nextval('test_test_id_seq'::regclass)
> email_a | character varying |
> email_b | character varying |
> Indexes:
> "test_pkey" PRIMARY KEY, btree (test_id)
>
> with this content:
>
> gullevek=# select * from test;
> test_id | email_a | email_b
> ---------+---------------+-------------
> 2 | test@xxxxxxxx | bar@xxxxxxx
> 1 | foo@xxxxxxx |
> (2 rows)
>
> if I do this select:
>
> select * from (select test_id, email_a FROM test WHERE email_a =
> 'moo@xxxxxxx') as s, (select test_id, email_b from test where email_b =
> 'bar@xxxxxxx') as t;
>
you get 0 rows. moo@xxxxxxx isn't anywhere and bar@xxxxxxx cannot do
pair with any. else 0 * 1 = 0
Pavel
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