How do I use properly CASE..WHEN in MySQL

Question

Here is a demo query, notice it is very simple, Fetches only where base_price is 0, And still, it chooses the condition 3:

SELECT
   CASE course_enrollment_s         


        

Answer 1

I think part of it is that you're stating the value you're selecting after CASE, and then using WHEN x = y syntax afterward, which is a combination of two different methods of using CASE. It should either be

CASE X
  WHEN a THEN ...
  WHEN b THEN ...

or

CASE
  WHEN x = a THEN ...
  WHEN x = b THEN ...