Silverlight在SubmitChanges时发生Submit operation failedSubmit operation failed

环境Silverlight+DomainService+EF

Unable to update the EntitySet ‘Reservation’ because it has a DefiningQuery and no <InsertFunction> element exists in the <ModificationFunctionMapping> element to support the current operation.

虽然在DomainService中设置了表可以编辑，但是在添加记录的时候出现了以上异常，经过问题的排查，发现是由于表没设置主键导致的。