Jan 02, 2012 07:10 PM|hans_v|LINK
In the SelectCommand, you should include the Primary Key field(s) of the StudenSubject Table (I assume it is called StudentSubjectID). The WHERE clause in your UpdateCommand should be:
UPDATE StudentSubject ...... WHERE StudentSubjectID = ?
And don't forget to change the UpdateParameters Collection accordingly
In the GridView, change the value of DataKeyNames property to "StudenSubjectID"