How to reuse a dynamic column in another column calculation in MySQL?

Question

I have this kinda query:

SELECT 
  IF(daycode=1,(SELECT...),(SELECT...)) AS weekavg,
  (SELLOFF1 / weekavg) AS procent
FROM .....

it tells me: Unknown column 'weekavg' in 'field list', this happens after I've added the divide, prior to that worked ok.

Answer 1

You can use a sub-query:

SELECT (selloff1 / weekavg) AS procent
FROM (
  SELECT 
    selloff1, IF(daycode=1,(SELECT...),(SELECT...)) AS weekavg
  FROM ...
)