Oracle question (may be simple for some of you.)

hi guys i got this table :

client     type     school
a           1          123
a           2          123  
b           1          123
b           2          123
c           1          123
d           2          123
e           3          123

please note that this table is created for this example.

i need to get thos client that their type is 1 and 2 so in this case i want clients a & b

How can i make the query to get those 2 only.

What I have tried:

i tried the query but it is not good :
select distinct client from table
where
(type = 1) or ( type = 2);

Tags: SQL, Oracle