title: Modifying a column with the 'Identity' pattern is not supported in WCF RIA Services
body: <p>I've been following the walkthrough for creating your first WCF RIA Services Application from Microsoft and have encountered a problem when trying to edit and update data using the SubmitChanges() method of the Data Context. </p>
  
  <p>The table being updated has an Identity Specification set in SQL Server 2008 on the 'CourseID' column. However the PRIMARY key is a composite of two other fields.</p>
  
  <p>When using SubmitChanges() the application locks up in the browser an presents an unhandled exception. By handling this exception I managed to get the message: Modifying a column with the 'Identity' pattern is not supported. This is referring to the 'CourseID' column. </p>
  
  <p>Turning identity specification off solves the problem, but I need the auto-incrementing ID. In what way isn't this supported. Or where am I going wrong?</p>