XmlDataDocument.DataSet Property

using System;
using System.Data;
using System.Xml;

public class Sample
{
  public static void Main()
  {
     //Create an XmlDataDocument.
     XmlDataDocument doc = new XmlDataDocument();

     //Load the schema file.
     doc.DataSet.ReadXmlSchema("store.xsd"); 

     //Load the XML data.
     doc.Load("2books.xml");

     //Update the price on the first book using the DataSet methods.
     DataTable books = doc.DataSet.Tables["book"];
     books.Rows[0]["price"] = "12.95";  

     Console.WriteLine("Display the modified XML data...");
     doc.Save(Console.Out);
  }
} // End class

<!--sample XML fragment-->
<bookstore>
  <book genre='novel' ISBN='10-861003-324'>
    <title>The Handmaid's Tale</title>
    <price>19.95</price>
  </book>
  <book genre='novel' ISBN='1-861001-57-5'>
    <title>Pride And Prejudice</title>
    <price>24.95</price>
  </book>
</bookstore>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

 <xsd:element name="bookstore" type="bookstoreType"/>

 <xsd:complexType name="bookstoreType">
  <xsd:sequence maxOccurs="unbounded">
   <xsd:element name="book"  type="bookType"/>
  </xsd:sequence>
 </xsd:complexType>

 <xsd:complexType name="bookType">
  <xsd:sequence>
   <xsd:element name="title" type="xsd:string"/>
   <xsd:element name="author" type="authorName"/>
   <xsd:element name="price"  type="xsd:decimal"/>
  </xsd:sequence>
  <xsd:attribute name="genre" type="xsd:string"/>
 </xsd:complexType>

 <xsd:complexType name="authorName">
  <xsd:sequence>
   <xsd:element name="first-name"  type="xsd:string"/>
   <xsd:element name="last-name" type="xsd:string"/>
  </xsd:sequence>
 </xsd:complexType>

</xsd:schema>