Multiple where in mysql query not returning anything -

i know easy question, why isn't query returning ?

mysql> select * notifications; +----+---------+-------------+---------+--------+---------------------+ | id | user_id | sec_user_id | item_id | action | date                | +----+---------+-------------+---------+--------+---------------------+ |  1 |       1 |        null |    null |   null | 2015-10-09 23:47:36 | +----+---------+-------------+---------+--------+---------------------+ 1 row in set (0.00 sec)  mysql> select id notifications user_id = 1 , action = null; empty set (0.00 sec) 

change action = null action null.