Two subselect into "IN" (oracle, sql)

Question

How can I use into "IN" two subselect?

I have now:

select colA, colB from table1 where colC in
                 (select T1 from tableT1 where colx = 'Y')
                 and ColD = 'Y';

I need too also that colC will be into second subselect:

select colA, colB from table1 where colC in
                 ((select T1 from tableT1 where colx = 'Y')
                  or
                 (select T2 from tableT2 where colx = 'Y'))
                 and ColD = 'Y';

It's possible to do that? or maybe some union?

Answer 1

You could use a union:

where colC in
(
    select T1 from tableT1 where colx = 'Y'
    union
    select T2 from tableT2 where colx = 'Y'
)
and ColD = 'Y'