Question

I have an XML file which contains data from a SQL DataSource. I need to refresh the file dynamically when new data is added to the database.

Answer 1

Use DataSet.GetXML

After you query your database and fill the adapter, If you detect data changes then
use the filled dataset to save the XML to disk:

string file ="c:\\newxml.txt";
System.IO.File.WriteAllText(file, ds.GetXml());