public static List <Product> LayDSThietBiTheoMaLoai(string maLoai) { List <Product> _ds = new List <Product>(); string sql = "select * from Product where id_cate = " + maLoai; DataTable dt = SqlDataAccessHelper.ExecuteQuery(sql); for (int i = 0; i < dt.Rows.Count; i++) { Product td = new Product(); td.Id = dt.Rows[i]["id"].ToString(); td.Id_cate = dt.Rows[i]["id_cate"].ToString(); td.Name_pro = dt.Rows[i]["name_pro"].ToString(); td.Qty = int.Parse(dt.Rows[i]["qty"].ToString()); td.Price = int.Parse(dt.Rows[i]["price"].ToString()); _ds.Add(td); } return(_ds); }