Access previous 'synthetic' column in select statement

Question

If I have a select statement like this

SELECT 
   t.time,
   <complicated computation> AS ticks,
   <is it possible to access the value of the ticks row here?> as num
FROM
   MyTable t;

Can I use the calculated value in column 2 as basis for calculations in column 3?

Answer 1

You need to wrap this in a subquery: it will look like this:

SELECT
    i.time as time,
    i.ticks as ticks,
    i.ticks + 10 as num
FROM
(
    SELECT 
       t.time as time,
       5 AS ticks
    FROM
       MyTable t
) AS i;