Hi
I'm developing a system with a large number of tables.
One of the tables has (among others) the following fields:
Table = aluno
+----------------------------------+---------------------------------
| Field | Type
+----------------------------------+---------------------------------
| numero_aluno | int4
| freguesia_naturalidade | int2
| concelho_naturalidade | int2
| nacionalidade | int2
another is like this:
-- Table = concelho
+----------------------------------+---------------------------------
| Field | Type
+----------------------------------+---------------------------------
| codigo | int4
| nome | text
The field "concelho_naturalidade" on the first table has values taken
from the "codigo" field from the second.
Now comes the problem:
When i do :
sac=> select a.numero_aluno, a.concelho_naturalidade from aluno a where
a.numero_aluno=13792;
i get:
numero_aluno|concelho_naturalidade
------------+--------------------- 13792| 1006
(1 row)
and whith:
sac=> select * from concelho where codigo=1006;
i get:
codigo|nome
------+---------------- 1006|CALDAS DA RAINHA
(1 row)
but with:
sac=> select c.nome from aluno a, concelho c where
a.concelho_naturalidade=c.codigo and a.numero_aluno=13792;
i get:
nome
----
(0 rows)
If my SQL is worth anything I thought it would reply "Caldas da Rainha".
What is wrong here?
I'm using POstgresql 6.3.2 (yes i know: I should upgrade)
Thanks
-- Mario Filipe mjnf@uevora.pt http://neptuno.sc.uevora.pt/~mjnf