A dillema ...

Hi

i have a table with the following schema :

Table = epoca
+---------------------------+----------------------------------+-------+
| Field | Type | Length|
+---------------------------+----------------------------------+-------+
| codigo | int4 | 4 |
| descricao | varchar() | 20 |
+---------------------------+----------------------------------+-------+

and another with

Table = aluno_inscricao
+---------------------------+----------------------------------+-------+
| Field | Type | Length|
+---------------------------+----------------------------------+-------+
| numero_aluno | int4 | 4 |
| codigo_disciplina | int4 | 4 |
| ano_lectivo | char() | 10 |
| epoca | int4 | 4 |
| semestre | bool | 1 |
+---------------------------+----------------------------------+-------+

The field epoca is an "index" to the table epoca.

The table epoca has :

sac=> select * from epoca;
codigo|descricao
------+-------------------
1|Normal
2|Especial
3|Recurso
6|Recurso Antecipado
4|Melhoria E. Normal
5|Melhoria E. Recurso

when selecting from instancia_disciplina for a particular
codigo_disciplina i get :

sac=> select distinct epoca from aluno_inscricao where
codigo_disciplina=671;
epoca
-----
1
3
4
5
6

Now if i want to get codigo and descricao from epoca according to the
results above i would do:

sac=> select distinct e.codigo, e.descricao from epoca e,
instancia_disciplina i where i.epoca=e.codigo and
i.codigo_disciplina=671;
codigo|descricao
------+-------------------
1|Normal
3|Recurso
5|Melhoria E. Recurso
6|Recurso Antecipado

Why doesn't codigo=4 show up, since before the join it did.

I tryed this both on 6.4 and 6.3.2 same results

THanks
--
Mario Filipe
mjnf(at)uevora(dot)pt
http://neptuno.sc.uevora.pt/~mjnf