public void HienThiDoanhThuTheoNam(string condition)
{
//dataGridView1.DataSource = bus.DoanThuTheoNam("Select Year(NgayLapHDBH) as 'Năm', format(sum([TongTien]),'N0') as 'Doanh thu'" +
// " From HoaDonBanHang Where YEAR(NgayLapHDBH) =" + condition + " Group by Year(NgayLapHDBH)");
cboDoanhThu.DataSource = bus.DoanThuTheoNam("Select format(sum([TongTien]),'N0') as TT" +
" From HoaDonBanHang Where YEAR(NgayLapHDBH) =" + condition + " ");
cboDoanhThu.DisplayMember = "TT";
}