datalist删除多行记录

 for (int i = 0; i < DataList1.Items.Count; i++)
        {
            CheckBox ck = (CheckBox)DataList1.Items[i].FindControl("select");
            if (ck.Checked)
            {
                int id = Convert.ToInt32(DataList1.DataKeys[i].ToString());
                SqlConnection cn = new SqlConnection("server=.;database=pubs;uid=sa;pwd=sa");
                cn.Open();
                SqlCommand cmd = new SqlCommand("delete from students where ID='" + id + "'", cn);
                cmd.ExecuteNonQuery();
                cn.Close();
                Response.Write("<script>alert('OK')</script>");
            }
        }