sql oracle - distinct missing expression

Question

I have the below query where i return all users, but they are users with the same TYPEUSER

select * from utilisateur ut where ut.TYPEUSER != 'classe' AND ut.TYPEUSER != 'user'

I tried with the below query to get unique users by TYPEUSER, but it returns this error ORA-00936: missing expression

select distinct ut.PRENOMUSER, * from utilisateur ut where ut.TYPEUSER != 'classe' AND ut.TYPEUSER != 'user'

Answer 1

Oracle allows select * . But if you select other columns, you need to qualify the * . So:

select distinct ut.PRENOMUSER, ut.*
from utilisateur ut
where ut.TYPEUSER <> 'classe' AND ut.TYPEUSER <> 'user';

This is just one of the syntactic weirdnesses of Oracle. Another is that as is not permitted in the FROM clause (I wouldn't use it anyway). I think it is because Oracle is the oldest database, long pre-dating the SQL standard.

Answer 2

You dont even need ut.PRENOMUSER in select clause. it is irrelevant.

Use following query:

select distinct ut.*
from utilisateur ut
where ut.TYPEUSER <> 'classe' AND ut.TYPEUSER <> 'user';