public async Task <bool> DeleteSubject(int id) { var subject = await subjectRepository.GetSubjectById(id); subject.isDelete = true; if (subject == null) { return(false); } testQuestionRepository.SetValueIsDeleteOnSubject(subject.Id); answersRepository.SetValueIsDeleteOnSubject(subject.Id); subjectRepository.Update(subject); await subjectRepository.SaveChangesAsync(); await testQuestionRepository.SaveChangesAsync(); await answersRepository.SaveChangesAsync(); return(true); }