The XmlDataDocument is a marriage of XML and RDBMS technology; it is an XmlDocument -inheriting class that particularly understands ADO.NET DataSet objects. This offers a variety of opportunities to the .NET programmerfor example, a DataSet can be loaded into the XmlDataDocument , and then navigated using traditional DOM-style navigation using the XmlNode API. In fact, because XmlDataDocument also inherits the System.Xml.XPath.IXPathNavigable interface, XPath queries can be issued against the DataSet data, as well. In order to build this relationship, construct the XmlDataDocument with the DataSet holding the data as its constructor parameter. Alternatively, use the Load( ) method to read in the data via an XmlReader . The resulting XML can also then be written out to another medium with the WriteTo( ) method. public class XmlDataDocument : XmlDocument { // Public Constructors public XmlDataDocument ( ); public XmlDataDocument (System.Data.DataSet dataset ); // Public Instance Properties public DataSet DataSet {get; } // Public Instance Methods public override XmlNode CloneNode (bool deep ); // overrides XmlDocument public override XmlElement CreateElement (string prefix , string localName , string namespaceURI ) // overrides XmlDocument public override XmlEntityReference CreateEntityReference (string name ) // overrides XmlDocument public override XmlElement GetElementById (string elemId ); // overrides XmlDocument public XmlElement GetElementFromRow (System.Data.DataRow r ); public DataRow GetRowFromElement (XmlElement e ); public override void Load (System.IO.Stream inStream ); // overrides XmlDocument public override void Load (string filename ); // overrides XmlDocument public override void Load (System.IO.TextReader txtReader ); // overrides XmlDocument public override void Load (XmlReader reader ); // overrides XmlDocument // Protected Instance Methods protected override XPathNavigator CreateNavigator (XmlNode node ) // overrides XmlDocument } HierarchySystem.Object XmlNode(System.ICloneable , System.Collections.IEnumerable , System.Xml.XPath.IXPathNavigable) XmlDocument XmlDataDocument |