Is there a way to give a subquery an alias in Oracle 11g SQL?

Question

Is there a way to give a subquery in Oracle 11g an alias like:

select * 
from
    (select client_ref_id, request from some_table where message_type = 1) abc,
            


        

Answer 1

Your query should be fine.

An alternative would be:

select abc.client_ref_id, abc.request, def.response
from   some_table abc,
       some_table def
where  abc.client_ref_id = def.client_ref_id
and    abc.message_type = 1
and    def.message_type = 2;

I wouldn't be surprised if Oracle rewrote the queries so that the plan would be the same anyway.