根据数据库生成XML二法

SqlConnection conn = new SqlConnection();
conn.ConnectionString = "Server=127.0.0.1;
User ID=sa;
Password=fdahgdrethj31313210212121;
Database=northwind;
Persist Security Info=True";
conn.Open();
SqlDataAdapter da = new SqlDataAdapter("select * from 表", conn);
SqlCommandBuilder thisBulder = new SqlCommandBuilder(da);
      DataSet ds = new DataSet();
      da.Fill(ds);
      ds.WriteXml(@"C:\temp.xml");
==============================================================================
private void WriteXmlToFile(DataSet thisDataSet) {
    if (thisDataSet == null) { return; }
    // Create a file name to write to.
    string filename = "myXmlDoc.xml";
    // Create the FileStream to write with.
    System.IO.FileStream myFileStream = new System.IO.FileStream (filename, System.IO.FileMode.Create);
    // Create an XmlTextWriter with the fileStream.
    System.Xml.XmlTextWriter myXmlWriter = new System.Xml.XmlTextWriter(myFileStream,System.Text.Encoding.Unicode);
    // Write to the file with the WriteXml method.
    thisDataSet.WriteXml(myXmlWriter);  
    myXmlWriter.Close();
}