private void GetByIdOperation() { long id = -1; while (id < 0) { id = view.EnterId(); } switch (view.entity) { case Entity.Pupil: List <Pupil> pupils = new List <Pupil>() { pupilDAO.Get(id) }; view.PrintPupils(pupils); break; case Entity.Teacher: List <Teacher> teachers = new List <Teacher>() { teacherDAO.Get(id) }; view.PrintTeachers(teachers); break; } }