static async Task ShowRegistrations_Bad(IDac dac)
{
var regs = await dac.GetRegistrations(it => true);
foreach (var reg in regs)
{
var student = await dac.GetStudent(it => it.Id == reg.StudentId);
var subject = await dac.GetSubject(it => it.Id == reg.SubjectId);
var teacher = await dac.GetTeacher(it => it.Id == subject.TeacherId);
Console.WriteLine($"{reg.Id:00}|{subject.Name}, {student.Name}, {teacher.Name}, {reg.Semester}, {reg.Grade}");
}
}