public DAL_Account() { db = new QuayThuocDataContext(); }
public DAL_Thuoc() { db = new QuayThuocDataContext(); }
public DAL_KhachHang() { db = new QuayThuocDataContext(); }
public DAL_NhaCungCap() { db = new QuayThuocDataContext(); }
public DAL_HoaDon() { db = new QuayThuocDataContext(); }