zero length string to zero

[Shadi Mal <shadi.mal71@xxxxxxxxx>]

Hi,

 I get zero length string in my result but I want to have zero value instead.

what can I do?

my query is:

SELECT unreadmandatory.id,

         Count(unreadmandatory.course) AS nbrofmandatoryleft

           FROM unreadmandatory

          GROUP BY unreadmandatory.id