第一个示例方法：
1 SqlConnection conn = new SqlConnection();
2 conn.ConnectionString = "Server=127.0.0.1;User
ID=sa;Password=fdahgdrethj31313210212121;
Database=northwind;Persist Security Info=True";
3 conn.Open();
4 SqlDataAdapter da = new SqlDataAdapter("select * from 表", conn);
5 SqlCommandBuilder thisBulder = new SqlCommandBuilder(da);
6 DataSet ds = new DataSet();
7 da.Fill(ds);
8 ds.WriteXml(@"C:temp.xml");
第二个示例方法：
1 private void WriteXmlToFile(DataSet thisDataSet)
2 {
3 if (thisDataSet == null) { return; }
4 // Create a file name to write to.
5 string filename = "myXmlDoc.xml";
6 // Create the FileStream to write with.
7 System.IO.FileStream myFileStream = new System.IO.FileStream
8 (filename, System.IO.FileMode.Create);
9 // Create an XmlTextWriter with the fileStream.
10 System.Xml.XmlTextWriter myXmlWriter =
11 new System.Xml.XmlTextWriter
(myFileStream, System.Text.Encoding.Unicode);
12 // Write to the file with the WriteXml method.
13 thisDataSet.WriteXml(myXmlWriter);
14 myXmlWriter.Close();
15 }