How to count NULL values in MySQL?

Question

I want to know how can i find all the values that are NULL in the MySQL database for example I\'m trying to display all the users who don\'t have an average yet.

Here i

Answer 1

A more generic version (that doesn't depend on the where clause and hence limits your overall results):

SELECT 
    SUM(CASE WHEN average IS NULL THEN 1 ELSE 0 END) As null_num, 
    SUM(CASE WHEN average IS NOT NULL THEN 1 ELSE 0 END) AS not_null_num
FROM users

It's not better then the specific queries presented by other answers here, but it can be used in situations where using a limiting where clause is impractical (due to other information being needed)...