SQL processing values of user defined columns

Question

I can do that:

SELECT
   1 AS one,
   2 AS two,
   1 + 2 AS three;

But I would like to do that:

SELECT
    1 AS one,
    2 AS two,
one + two AS three;

Is it possible?

Answer 1

You can do this:

SELECT one, two, (one+two) as three
FROM 
(
    SELECT 
         1 AS one 
         2 AS two
) t;