How to retrieve data from database and set into the check-boxes

I have a form in a c# application in which I am saving values from checkboxes to database. Now what I need to do is that to retrieve the saved values on same form for updating and editing purpose.

For example I have used this query to retrieve the data:

     "Select * from tblComplaints where ID = txtID.Text"

Here I want to know that How can I set the !null values on check-boxes?