程序段中对语句作了说明。主要使用XmlWriter类进行XML文件生成。
下面这是由关系数据库生成相应XML文件过程。由于XML只是中间件，所以忽略了Schema或者DTD。
 1        private void Page_Load(object sender, System.EventArgs e)
 2        {
 3            // 在此处放置用户代码以初始化页面
 4            //基本信息定义
 5            String strTableName="systypes";
 6            String strConnection="server=suntears;user id=sa;password=041210;database=webapplication1_db";
 7            String strSql="select * from "+strTableName;
 8            SqlConnection objConn=new SqlConnection(strConnection);
 9            SqlDataAdapter objAdapter=new SqlDataAdapter(strSql,objConn);
10            DataSet objDSet=new DataSet();
11            objAdapter.Fill(objDSet,"temp");
12            XmlTextWriter objXmlWriter;
13            String strtemp1=Request.PhysicalApplicationPath;
14            String strpath=strtemp1+"qiming.xml";
15            //初始化XmlWriter.用此类写XML文件
16            objXmlWriter=new XmlTextWriter(strpath,null);
17            //创建开头的XML声明
18            objXmlWriter.WriteStartDocument();
19            //创建根元素xml1
20            objXmlWriter.WriteStartElement("xml1");
21            //表名为元素名，字段名为属性，表中的记录为属性的值
22            for(int i=0;i<objDSet.Tables["temp"].Rows.Count;i++)
23            {
24            objXmlWriter.WriteStartElement("menu");
25                for(int j=0;j<objDSet.Tables["temp"].Columns.Count;j++)
26                {
27                    //写入属性
28                    objXmlWriter.WriteAttributeString(objDSet.Tables["temp"].Columns[j].ColumnName,objDSet.Tables["temp"].Rows[i][j].ToString());
29                }
30                objXmlWriter.WriteEndElement();
31            }
32            objXmlWriter.WriteEndElement();
33            objXmlWriter.WriteEndDocument();
34            //用close方法关闭文件，否则文件将被锁定
35            objXmlWriter.Close();
36            // 在页面上显示结果
37            string strXmlResult;
38            StreamReader objSR = File.OpenText(strpath);
39            strXmlResult = objSR.ReadToEnd();
40            objSR.Close();
41            Response.Write("<pre>" + Server.HtmlEncode(strXmlResult) + "<pre>");
42        }
下面是通过上面程序生成的XML文件生成关系数据库的代码

 1        private void Page_Load(object sender, System.EventArgs e)
 2        {
 3            // 在此处放置用户代码以初始化页面
 4            //基本信息定义
 5            int cx=1;
 6            string strConn="server=suntears;user id=sa;password=;database=xml_example";
 7            string strappstr=Request.PhysicalApplicationPath;
 8            string strpath=strappstr+"qiming.xml";
 9            string strtablename="xml1";
10            string strCreatetable="create table "+strtablename+"(";
11            XmlTextReader objXmlReader=new XmlTextReader(strpath);
12            SqlConnection objConn=new SqlConnection(strConn);
13            SqlCommand objCommand;
14            SqlDataAdapter objAdapter;
15            DataSet objDSet=new DataSet();
16            DataRow objrow;
17            XmlNodeType objNodeType;
18            //采用XmlReader类进行XML文件访问操作
19            //XmlReader采用拉（pull）模式。因此通过Read()方法迭代各个节点
20            while(objXmlReader.Read())
21            {
22                objNodeType=objXmlReader.NodeType;
23                //根据节点类型进行不同操作
24                switch(objNodeType)
25                {
26                    //XML文件开头的声明
27                    case XmlNodeType.XmlDeclaration:
28                        Response.Write("11111"+objXmlReader.Name+"<br>");
29                        break;
30                    //正常节点类型
31                    case XmlNodeType.Element:
32                        //根据属性个数判断是否是根元素
33                        if(objXmlReader.AttributeCount>0)
34                        {
35                            //cx作为标志位。第一次访问非根元素节点时根据元素结构生成数据库
36                            if(cx==1)
37                            {
38                                while(objXmlReader.MoveToNextAttribute())
39                                {
40                                    strCreatetable=strCreatetable+objXmlReader.Name+" varchar(50), ";
41                                }
42                                strCreatetable=strCreatetable+")";
43                                objCommand=new SqlCommand(strCreatetable,objConn);
44                                objConn.Open();
45                                objCommand.ExecuteNonQuery();
46                                objConn.Close();
47                                objAdapter=new SqlDataAdapter("select * from "+strtablename,objConn);
48                                objAdapter.Fill(objDSet,strtablename);
49                                objXmlReader.MoveToFirstAttribute();
50                                //更改标志为cx数值
51                                cx=0;
52                            }
53                            //将XML文件中数据转存到DataSet对象中
54                            objrow=objDSet.Tables[strtablename].NewRow();
55                            objXmlReader.MoveToFirstAttribute();
56                            for(int j=0;j<objXmlReader.AttributeCount;j++)
57                            {
58                                objrow[j]=objXmlReader.Value.ToString();
59                                objXmlReader.MoveToNextAttribute();
60                            }
61                            objDSet.Tables[strtablename].Rows.Add(objrow);
62                        }
63                        break;
64                }
65            }
66            //显示转存后的数据表
67            DataGrid1.DataSource=objDSet.Tables[strtablename];
68            DataGrid1.DataBind();
69        }将数据更新到数据库的代码没有编写，自己弄吧^_^

http://suntears.cnblogs.com/archive/2006/06/02/416207.html