public DAL_YeuCauSuaChua() { conn = new DBconnection(); }
public DAL_HoaDon() { conn = new DBconnection(); }
public DAL_ThietBiSuaChua() { conn = new DBconnection(); }
public DAL_NhanHieu() { conn = new DBconnection(); }
public DAL_KhachHang() { conn = new DBconnection(); }
public DAL_NhapThietBi() { conn = new DBconnection(); }
public DAL_Statistics() { conn = new DBconnection(); }
public DAL_SuaChua() { conn = new DBconnection(); }