[Test]
[ExpectedException(typeof(ServiceExceptionUserAlreadyExisted))]
public void AddUserWithAnExistedLoginInfo()
{
   IDAL dal = new DALImpl();

   Person perEntity = new Person();
   perEntity.Name = "TestPerson";

   LoginInfo logifo = new LoginInfo();

                //loginname Field is unique="true" in the database
   logifo.LoginName = "admin";
   logifo.Password = "123";

                //one- to -one
   perEntity.TheLoginInfo = logifo;
   logifo.ThePerson = perEntity;

   dal.SaveEntity(perEntity);
}

InnerException = {"Violation of UNIQUE KEY constraint 'UQ__TLoginInfo__38E54BF0'. Cannot insert duplicate key in object 'TLoginInfo'.\r\nThe statement has been terminated."}

{"Object reference not set to an instance of an object."}