How do I combine 2 select statements into one?

Question

I am a noob when it comes to SQL syntax.

I have a table with lots of rows and columns of course :P Lets say it looks like this:

      AAA BBB CCC DD         


        

Answer 1

use a case into the select and use in the where close a OR

something like this, I didn't tested it but it should work, I think...

select case when CCC='D' then 'test1' else 'test2' end, *
from table
where (CCC='D' AND DDD='X') or (CCC<>'D' AND DDD='X')