static void Main(string[] args) { var user = new User(); var dept = new Department(); IFactory factory = new SqlServerFactory(); IUserOperation iOper = factory.CreateUserOperation(); iOper.Insert(user); iOper.GetUser(1); factory = new AccessFactory(); IDepartmentOperation id = factory.CreateDepartmentOperation(); id.Insert(dept); id.GetDepartment(1); Console.Read(); }