public void Add(User user)
 {
     using (var db = new LectureRegistrationSystemDbContext())
     {
         db.Users.Add(user);
         db.SaveChanges();
     }
 }
 public User GetByUsername(string username)
 {
     using (var db = new LectureRegistrationSystemDbContext())
     {
         return(db.Users
                .FirstOrDefault(u => u.Username == username));
     }
 }
 public List <User> Get()
 {
     using (var db = new LectureRegistrationSystemDbContext())
     {
         return(db.Users
                .ToList());
     }
 }