Testing for IS NULL within query

[monkey64]

I have a database with some null values.
I understand that I should be able to use IS NULL within my query.

SELECT * FROM `mytable` WHERE  mycol IS NULL

From within PhpMyAdmin, I get this:
MySQL returned an empty result set (i.e. zero rows).

What am I doing wrong?

 

[monkey64]

Actually, I just answewd my own question.
The value appeared NULL, but testing for "WHERE mycol = ''", showed the missing values.

So I learnt a lesson...