Question

I’m using this MySQL query

SELECT COUNT(pros_a) + COUNT(pros_b) + COUNT(pros_c) + COUNT(pros_d) + COUNT(pros_e) AS pros_total FROM my_table WHERE contentid = 'id'

to count and sum fields in each column. But this returns ALL fields (full and empty). I want to count only filled fields, excluding empty fields. How can I do that? Just a little bit… confused! 🙂

Any help would be very appreciated!
Thanks

EDIT:

my_table

pros_a   pros_b   pros_c   pros_d   pros_e
-------  ------   ------   ------   ------
good     (empty)  good     good     (empty)

expected result

pros_total
----------
3

Answer 1

The COUNT(column) function does not count fields that are NULL. It counts empty (zero-length) strings though.

You can change these into:

COUNT( CASE WHEN column <> '' THEN column END )

or:

SUM(column <> '')

The last works in MySQL because TRUE is evaluated as 1 and FALSE as 0.