I followed steps to use LINQ to SQL using stored procedures to update the database records. the problem I have is calling submitChanges() did not update the record in the database.

I am using SQL 2008 Express with a connection string, in the code, after called submitChanges(0, I did a databinding using Gridview, the gridview shows the changes, but when I navigate away, then come back, the change is lost. Checking the database record, no updates. What is the problem?

Other question, in the code, I only put the columnes that need update, not all the columnes. Do I need to put all of them there, even some columnes do not need update?

Thanks.