public List <HocSinh_DTO> LayHocSinhTheoLop(int id)
        {
            List <HocSinh_DTO> DSHS = new List <HocSinh_DTO>();
            DataTable          data = DataProvider.Instance.ExecuteQuery("select hocsinh.*,TenLop from hocsinh join lop on HocSinh.MaLop = Lop.MaLop where HocSinh.MaLop = " + id);

            foreach (DataRow item in data.Rows)
            {
                HocSinh_DTO hs = new HocSinh_DTO(item);
                DSHS.Add(hs);
            }
            return(DSHS);
        }
        public List <HocSinh_DTO> TimKiemHS(string param)
        {
            List <HocSinh_DTO> DSHS  = new List <HocSinh_DTO>();
            string             query = string.Format("select hocsinh.*,TenLop from hocsinh join lop on HocSinh.MaLop = Lop.MaLop where TenHocSinh like N'%{0}%'", param);
            DataTable          data  = DataProvider.Instance.ExecuteQuery(query);

            foreach (DataRow item in data.Rows)
            {
                HocSinh_DTO hs = new HocSinh_DTO(item);
                DSHS.Add(hs);
            }
            return(DSHS);
        }