select *
from
(
(select id from caw_communities) a
union ALL
(select id from caw_tabs) b
)
;
this gives the error missing right parenthesis...

I'm trying to do this to use your code you posted
Select . . . from A
UNION ALL
Select . . . from B
Where not exists
(select * from A
where A.id = B.id)

table A is going to be a combination of tables and so is table B and that iswhy i'm trying to name them, so that when i do the

where no exists i can use A.id and B.id