public void MuonSach(int id, MuonSachModel model)
        {
            var entity = new MuonTraSach()
            {
                SachId   = id,
                DocGiaId = model.DocGiaId,
                //   SachId = model.SachId,
                NgayMuon = model.NgayMuon
            };
            var docGia = _docGiaRepository.Get(model.DocGiaId);

            _muonTraSachRepository.Insert(entity);
            docGia.SoSachDangMuon += 1;
            _docGiaRepository.Update(docGia);
        }
        public void DeleteDocGia(int id)
        {
            var docGia = _repository.Get(id);

            _repository.Delete(docGia);
        }