学习如何把数据库数据提取为XML

学习如何把数据库数据提取为XML
代码：
news.mdb数据库结构：News(id,title,content,time)

string fileurl = System.Web.HttpContext.Current.Server.MapPath("App_Data") + "\\" + "news.mdb";
        OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OleDb.4.0;Data Source=" +fileurl);
        OleDbDataAdapter oda = new OleDbDataAdapter("Select *FROM News",con);
        DataSet ds = new DataSet();
        oda.Fill(ds,"News");

        DataTable dt=ds.Tables["News"];

        XmlDocument xdoc = new XmlDocument();
        //创建XML申明
        XmlDeclaration xdecl = xdoc.CreateXmlDeclaration("1.0", "gb2312", "yes");
        xdoc.AppendChild(xdecl);
        //创建根元素

        XmlElement x_emt = xdoc.CreateElement("news");
        xdoc.AppendChild(x_emt);

        //从数据库读取数据加到XML中

        for (int i = 0; i < dt.Rows.Count;i++)
        {
            XmlElement xmnew = xdoc.CreateElement("new");

            XmlElement xemt = xdoc.CreateElement("ID");
            xemt.InnerText = dt.Rows[i]["id"].ToString();
            xmnew.AppendChild(xemt);

            XmlElement xemt1 = xdoc.CreateElement("TITLE");
            xemt1.InnerText = dt.Rows[i]["title"].ToString();
            xmnew.AppendChild(xemt1);

            XmlElement xemt2 = xdoc.CreateElement("CONTENT");
            xemt2.InnerText = dt.Rows[i]["content"].ToString();
            xmnew.AppendChild(xemt2);

            XmlElement xemt3 = xdoc.CreateElement("TIME");
            xemt3.InnerText = dt.Rows[i]["time"].ToString();
            xmnew.AppendChild(xemt3);

            xdoc.DocumentElement.AppendChild(xmnew);
        }

        //输出保存
        xdoc.Save(@"E:\我的站点\admin\News.xml");

总结：添加XML节点时一定要把子节点添加到对应的父结点下，根节点只能有一个。