MySQL: NULL value comparison issue

As a PHP developer I was surprised when query like this:
SELECT IF(‘Bonus’ <> NULL, 1, 0)

returned 0

Any arithmetic comparison with NULL does not return true or false, but returns NULL instead

As an alternative guys propose <=> operator called NULL – safe equal to operator.

So my query will look like this:

SELECT IF(!(‘Bonus’ <=> NULL), 1, 0)

This can be tricky to debug, so hopefully it will help someone.