这个语句哪里有错？

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["SDataConnectionString"].ConnectionString);
        conn.Open();
        string strSelStu = "select top(5) [ID] ,[Or_Grade], [Or_Subject], [Or_tInfo] , [Or_tSex] , [Or_AdDate] , [Or_District] From [OrderTeacher] Order By [ID] DESC";
        DataSet Studs = new DataSet();

        SqlDataAdapter Studa = new SqlDataAdapter(strSelStu, conn);
        Studa.Fill(Studs, "OrderTeacher");
        DLStu.DataSource = Studs;
        DLStu.DataMember = "OrderTeacher";
        DLStu.DataBind();