public ArrayList<OfflineStatistic> getDonHangOffline()
    {
        ArrayList<OfflineStatistic> loff = new ArrayList<>();
        try{
            PreparedStatement ps = conn.prepareStatement("SELECT TOP 1000 [DonHangID]\n" +
"      ,[NhanvienID]\n" +
"  FROM [httql].[dbo].[DonHangOffline]");
            ResultSet rs = ps.executeQuery();
            OfflineStatistic off = new OfflineStatistic();
            while(rs.next())
            {
                off.setDhid(rs.getInt("DonHangID"));
                System.out.println(rs.getInt("DonHangID"));
                PreparedStatement st1 = conn.prepareStatement("SELECT TOP 1000 [ID]\n" +
"      ,[ngaydathang]\n" +
"      ,[ChiNhanhID]\n" +
"      ,[MaGiamGiaID]\n" +
"  FROM [httql].[dbo].[DonHang] WHERE ID = ?");
                st1.setInt(1, off.getDhid());
                System.out.println(off.getDhid());

                ResultSet rs1 = st1.executeQuery();
                rs1.next();
                off.setDate(rs1.getString("ngaydathang"));
                ps = conn.prepareStatement("SELECT [STT]\n" +
"		, [ID]\n" +
"      ,[soluong]\n" +
"      ,[SanphamID]\n" +
"      ,[DonHangID]\n" +
"      ,[gia]\n" +
"	  ,[tensp]\n" +
"  FROM [httql].[dbo].[ChiTietDonHang], [httql].[dbo].[Sanpham] WHERE [SanphamID] = [ID] AND [DonHangID] = ?");

                        ps.setInt(1, off.getDhid());
                        ResultSet rs2 = ps.executeQuery();
                while(rs2.next())
                {
                    SanPham sp = new SanPham();
                    sp.setId(rs2.getInt("SanphamID"));
                    sp.setTen(rs2.getString("tensp"));
                    sp.setGia(rs2.getInt("gia"));
                    sp.setSoluong(rs2.getInt("soluong"));
                    off.getLsp().add(sp);
                }
                loff.add(off);
            }

        }catch(Exception e){
            System.out.println(e);
        }
           return loff;
    }