public bool DeleteStudentByEmail(string email)
        {
            Student toDelete = _repository.GetSingle <Student>(x => x.Email.Equals(email));

            if (toDelete == null)
            {
                return(false);
            }
            else
            {
                try
                {
                    _repository.Delete <Student>(toDelete);
                    _repository.Commit();

                    return(true);
                }
                catch (SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
            }
        }