c#根据mssql读取数据导出xml，求教，紧急解决办法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Xml.Linq;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        SqlConnection conn = new SqlConnection(sqlconstring());
        public Form1()
        {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {

        }
        private static string sqlconstring()
        {
            string connstr = "Data Source=.;Initial Catalog=pp;Integrated Security=True";
            return connstr;
        }
        private static string mujiedian()
        {
            string zhujiedian = "select loc,lastmod,changefreq,priority from pp";
            return zhujiedian;
        }
        private static string zijiedian() {
            string zijiedian = "select title,expirationdate,description,type,city,employer,email,jobfirstclass,jobsecondclass,education,experience,startdate,enddate,salary,industry,employertype,source,sourcelink from pp";
            return zijiedian;
        }
        private static string lujing()
        {
            string dir = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory) + "/招聘信息.xml";
            return dir;
        }
        public void jiajiedian()
        {
            conn.Open();
            SqlCommand cmd = new SqlCommand(mujiedian(), conn);
            SqlDataReader dr = cmd.ExecuteReader();
            XDocument document = new XDocument();
            XElement root = new XElement("urlset");
            XElement element = new XElement("url");
            while (dr.Read())
            {
                for (int i = 0; i < dr.FieldCount; i++)
                {
                    element.Add(new XElement(dr.GetName(i), dr.GetValue(i)));
                }
                dr.Dispose();
                {
                    SqlCommand cmd2 = new SqlCommand(zijiedian(), conn);
                    SqlDataReader dr2 = cmd2.ExecuteReader();
                    while (dr2.Read()) { for (int j = 0; j < dr2.FieldCount; j++) {
                        element.Add(new XElement("data", new XElement("display", new XElement(dr2.GetName(j),dr2.GetValue(j)))));
                    
                    
                    } }


                } 
                root.Add(element);
            }
            document.Add(root);
            document.Save(lujing());
            conn.Close();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            jiajiedian();
           
           
        }
    }
}

<?xml version="1.0" encoding="utf-8" ?> 
- <urlset>
- <url>
  <loc>http://jobs.zhaopin.com/P5/CC0000/1824/J902/500/CC000018244J90250002000.htm</loc> 
  <lastmod>2010-04-06</lastmod> 
  <changefreq>always</changefreq> 
  <priority>1.0</priority> 
- <data>
- <display>
- <title>
- <![CDATA[  HPSW-Senior R&D Manager-Shanghai
  ]]> 
  </title>
  <expirationdate>2011-01-17</expirationdate> 
- <description>
- <![CDATA[ 
 HP is a leading global provider of products, technologies, solutions and services to consumers and business. 
The company's offerings span IT infrastructure, personal computing and access devices, global services, and printing. 
Our $4 billion annual R&D investment fuels the invention of products, solutions and new technologies. 
We invent, engineer that drive business value, improve the lives of our customers. 

  ]]> 
  </description>
  <type>社会招聘</type> 
  <city>上海</city> 
- <employer>
- <![CDATA[  惠普公司
  ]]> 
  </employer>
- <email>
- <![CDATA[  https://hp.taleo.net/careersection/2/jobdetail.ftl?lang=en&job=1720103&media_id=1009&src=Zhaopin
  ]]> 
  </email>
- <jobfirstclass>
- <![CDATA[  计算机软、硬件/互联网/IT
  ]]> 
  </jobfirstclass>
- <jobsecondclass>
- <![CDATA[  高级软件工程师
  ]]> 
  </jobsecondclass>
  <education>本科</education> 
  <experience>5年以上</experience> 
  <startdate>2010-04-05</startdate> 
  <enddate>2011-01-17</enddate> 
  <salary>面议</salary> 
- <industry>
- <![CDATA[  IT服务（系统/数据/维护）/多领域经营,计算机硬件及网络设备
  ]]> 
  </industry>
  <employertype>合资</employertype> 
  <source>智联招聘</source> 
- <sourcelink>
- <![CDATA[ http://www.zhaopin.com/
  ]]> 
  </sourcelink>
  </display>
  </data>
  </url>
- <url>
  <loc>http://jobs.zhaopin.com/P2/CC1204/9901/J902/501/CC120499019J90250131000.htm</loc> 
  <lastmod>2010-05-13</lastmod> 
  <changefreq>always</changefreq> 
  <priority>1.0</priority> 
- <data>
- <display>
- <title>
- <![CDATA[ 城市销售代表（温州/宁波）
  ]]> 
  </title>
  <expirationdate>2010-07-25</expirationdate> 
- <description>
- <![CDATA[ 
岗位职责：分别负责东芝宏碁产品温州及周边和宁波及周边区域销售，包括该品牌数码港，4－6级指标销售。
岗位要求：
1，本科以上，一年以上IT或快销销售经验，有渠道和区域销售经验者优先考虑；
2，本科以上，一年以上IT或快销销售经验，有渠道和区域销售经验者优先考虑

  ]]> 
  </description>
  <type>社会招聘</type> 
  <city>宁波</city> 
- <employer>
- <![CDATA[ 杭州神州数码有限公司
  ]]> 
  </employer>
- <email>
- <![CDATA[ 
  ]]> 
  </email>
- <jobfirstclass>
- <![CDATA[ 销售业务
  ]]> 
  </jobfirstclass>
- <jobsecondclass>
- <![CDATA[ 渠道/分销专员
  ]]> 
  </jobsecondclass>
  <education>本科</education> 
  <experience>1-3年</experience> 
  <startdate>2010-05-13</startdate> 
  <enddate>2010-07-25</enddate> 
  <salary>1000-50000元/月</salary> 
- <industry>
- <![CDATA[ 计算机硬件及网络设备,计算机软件,IT服务（系统/数据/维护）/多领域经营,通讯（设备/运营/增值服务）
  ]]> 
  </industry>
  <employertype>合资</employertype> 
  <source>智联招聘</source> 
- <sourcelink>
- <![CDATA[ http://www.zhaopin.com/
  ]]> 
  </sourcelink>
  </display>
  </data>
  </url>
  <url>...</url> 
  ... 
  </urlset>