static void StudentChioce() { IStudentReposytory studentReposytory = Factories.GetFactory().GetStudentReposytory(); string key; do { Console.WriteLine("What do u want to do? Get all students?(all). Add student?(add). Update student?(update). Delete?(del). To back enter (b)"); key = Console.ReadLine(); try { if (key == "all") { Console.WriteLine("There are such students: "); Console.WriteLine(); foreach (var students in studentReposytory.GetAllStudents()) { Console.WriteLine(string.Format("ID: {0}, First name: {1}, Last name: {2}, Birth: {3}, Academic group: {4}", students.Id, students.FirstName, students.LastName, students.Birth, students.Group_number)); } Console.WriteLine(); } else if (key == "add") { Console.WriteLine("Enter id for new student: "); int ID_for_new_elem = int.Parse(Console.ReadLine()); Console.WriteLine("Enter first name for new student: "); string Name_for_new_student = Console.ReadLine(); Console.WriteLine("Enter last name for new student: "); string Last_name_for_student = Console.ReadLine(); Console.WriteLine("enter new date of birth: "); DateTime Date_of_birth = Convert.ToDateTime(Console.ReadLine()); Console.WriteLine("enter academic group: "); int Academic_group = int.Parse(Console.ReadLine()); studentReposytory.Add(new Student { Id = ID_for_new_elem, FirstName = Name_for_new_student, LastName = Last_name_for_student, Birth = Date_of_birth, Group_number = Academic_group }); } else if (key == "update") { Console.WriteLine("Enter id of student u want to update: "); int IdForUpdating = int.Parse(Console.ReadLine()); Console.WriteLine("enter new name: "); string NameForUpdating = Console.ReadLine(); Console.WriteLine("enter new last name: "); string LastNameForUpdate = Console.ReadLine(); Console.WriteLine("enter new date of birth: "); DateTime Date_of_birth = Convert.ToDateTime(Console.ReadLine()); Console.WriteLine("enter new academic group: "); int Academic_group = int.Parse(Console.ReadLine()); studentReposytory.Update(new Models.Student { Id = IdForUpdating, FirstName = NameForUpdating, LastName = LastNameForUpdate, Birth = Date_of_birth, Group_number = Academic_group }); } else if (key == "del") { Console.WriteLine("Enter id of student u want to delete: "); int x = int.Parse(Console.ReadLine()); studentReposytory.Delete(new Models.Student { Id = x }); } } catch (Exception e) { Console.WriteLine(e.Message); continue; } Console.WriteLine("-------------------------------"); } while (key != "b"); }