Question

I don’t know why it’s is error on SaveChanges(), i search in google, some body say using EF, the database’s table such have primary key, i have this, but still error. The error message is not enough clear,it just throws System.Data.UpdateException.
The Code:

public static void AddAccount(int _acc_id,string _name)
{
    dataEntities de = new dataEntities(GetEntityConn());
    account acc = new account
    {
        account_id = _acc_id,
        name =  _name
    };
    de.AddObject("account", acc);
    de.SaveChanges();
}

Answer 1

Solved : I found the solution, see this thread : http://social.msdn.microsoft.com/Forums/en-US/sqlce/thread/48984bd4-0921-4637-bd8f-8aa1ae9514ab
For short, don’t use int as datatype , use uniqueidentifier type.This problem will not happen on SQL Server, it only occur when using SQLCE.