将DataSet中的数据写入XML

protected void Button1_Click(object sender, EventArgs e)
        {
            string conStr = ConfigurationManager.ConnectionStrings["lianxiConnectionString"].ConnectionString;
            using (SqlConnection conn=new SqlConnection(conStr))
            {
                conn.Open();
                using (SqlCommand cmd=conn.CreateCommand())
                {
                    string sql = "select * from students";
                    cmd.CommandText = sql;
                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    DataSet ds = new DataSet();
                    adapter.Fill(ds);
                    ds.WriteXml(Server.MapPath("writeXML.xml"));
                    Response.Write("<script>alert(‘写入成功‘);location=‘writeXML.xml‘</script>");
                }
            }
        }