causes the the child rows to be nested within the parent rows in the output XML

   
 

using System;
using System.Data;
using System.Data.SqlClient;

class NestedXml {
    public static void Main() {
        SqlConnection mySqlConnection = new SqlConnection("server=localhost;database=Northwind;uid=sa;pwd=sa");

        SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
        mySqlCommand.CommandText =
          "SELECT TOP 2 CustomerID, CompanyName " +
          "FROM Customers " +
          "ORDER BY CustomerID;" +
          "SELECT OrderID, CustomerID, ShipCountry " +
          "FROM Orders " +
          "WHERE CustomerID IN (" +
          "  SELECT TOP 2 CustomerID " +
          "  FROM Customers " +
          "  ORDER BY CustomerID " +
          ")";
        SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter();
        mySqlDataAdapter.SelectCommand = mySqlCommand;
        DataSet myDataSet = new DataSet();
        mySqlConnection.Open();
        int numberOfRows = mySqlDataAdapter.Fill(myDataSet);
        Console.WriteLine("numberOfRows = " + numberOfRows);
        mySqlConnection.Close();
        DataTable customersDT = myDataSet.Tables["Table"];
        DataTable ordersDT = myDataSet.Tables["Table1"];
        DataRelation customersOrdersDataRel =
          new DataRelation(
            "CustomersOrders",
            customersDT.Columns["CustomerID"],
            ordersDT.Columns["CustomerID"]
          );
        myDataSet.Relations.Add(
          customersOrdersDataRel
        );
        myDataSet.WriteXml("nonNestedXmlFile.xml");
        myDataSet.Relations["CustomersOrders"].Nested = true;
        myDataSet.WriteXml("nestedXmlFile.xml");
    }
}