mysql SELECT列但只使用WHERE

Question

I have this query:

SELECT  i.d, COUNT(id) AS dr, COUNT(id2) AS dn, SUM(eq) AS eq_sum, COUNT(thx) AS thx_count 
FROM dsd
  INNER JOIN 
    (
      SELECT COUNT(id) AS d FROM ds
    ) i

Now I want to use WHERE only to column thx like WHERE thx="y" , so that it will count only all values with "y".

But If I just add WHERE at the end of the query it will affect other columns as well which I don't want to.

How to do this?

Answer 1

Then change your COUNT(thx) AS thx_count to below using CASE expression like

COUNT(CASE WHEN thx = 'y' THEN 1 ELSE 0 END) AS thx_count

(OR)

SUM(CASE WHEN thx = 'y' THEN 1 ELSE 0 END) AS thx_count