Query problem

2007/10/12, Clemens Schwaighofer <cs@tequila.co.jp>:

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@test.com | bar@foo.com
1 | foo@bar.com |
(2 rows)

if I do this select:

select * from (select test_id, email_a FROM test WHERE email_a =
'moo@boo.com') as s, (select test_id, email_b from test where email_b =
'bar@foo.com') as t;

you get 0 rows. moo@boo.com isn't anywhere and bar@foo.com cannot do
pair with any. else 0 * 1 = 0

Pavel

On 2007/10/12, at 23:22, Pavel Stehule wrote:

you get 0 rows. moo@boo.com isn't anywhere and bar@foo.com cannot do
pair with any. else 0 * 1 = 0

Thanks, go it now. Basically very simple.

I probably need to approach the problem different. So both are read
"independent" or something like this.

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On 10/12/07, Clemens Schwaighofer <cs@tequila.co.jp> wrote:

I probably need to approach the problem different. So both are read
"independent" or something like this.

Also, email_a, email_b, etc. indicate that you need to consider
refactoring your schema.

You can find a lot of tutorials on normalization online.