‫Entity Framework و InnerException

        public static string ExceptionToString(this Exception ex)
        {
            StringBuilder errorMsg = new StringBuilder();
            for (Exception current = ex; current != null; current = current.InnerException)
            {
                if (errorMsg.Length > 0)
                    errorMsg.Append("\n");
                errorMsg.Append(current.Message.
                    Replace("See the inner exception for details.", string.Empty));
            }
            return errorMsg.ToString();
        }

catch (Exception ex)
                {
                    // log
                    ex.ExceptionToString();
                }