Public Sub GetChildRowsFromDataRelation()
    ' For each row in the table, get the child rows using the
    ' ChildRelations. For each item in the array, print the value
    ' of each column.
    Dim table As DataTable = CreateDataSet().Tables("Customers")

    Dim childRows() As DataRow
    Dim relation as DataRelation
    Dim row as DataRow
    For Each  relation In table.ChildRelations
        For Each row In table.Rows
            PrintRowValues(new DataRow() {row}, "Parent Row")
            childRows = row.GetChildRows(relation)
            ' Print values of rows.
            PrintRowValues(childRows, "child rows")
        Next row
    Next relation
End Sub

Public Function CreateDataSet() As DataSet
    ' create a DataSet with one table, two columns
    Dim dataSet As DataSet
    dataSet = new DataSet()

    ' create Customer table
    Dim table As DataTable
    table = new DataTable("Customers")

    dataSet.Tables.Add(table)
    table.Columns.Add("customerId", _
        GetType(Integer)).AutoIncrement = true
    table.Columns.Add("name", GetType(String))
    table.PrimaryKey = new DataColumn() _
        { table.Columns("customerId") }

    ' create Orders table
    table = new DataTable("Orders")
    dataSet.Tables.Add(table)
    table.Columns.Add("orderId", GetType(Integer)).AutoIncrement = true
    table.Columns.Add("customerId", GetType(Integer))
    table.Columns.Add("amount", GetType(Double))
    table.PrimaryKey = new DataColumn() { table.Columns("orderId") }

    ' create relation
    dataSet.Relations.Add(dataSet.Tables("Customers").Columns("customerId"), _
        dataSet.Tables("Orders").Columns("customerId"))
    
    ' populate the tables
    Dim orderId As Integer = 1
    Dim customerId As Integer
    Dim i As Integer
    For customerId = 1 To 10
        ' add customer record
        dataSet.Tables("Customers").Rows.Add( _
            new object() { customerId, _
            string.Format("customer{0}", customerId) })
        
        ' add 5 order records for each customer

        For i = 1 To 5
            dataSet.Tables("Orders").Rows.Add( _
                new object() { orderId, customerId, orderId * 10 })
        
        orderId = orderId+1 
    Next
    Next

    CreateDataSet = dataSet
End Function

private sub PrintRowValues(rows() As DataRow, label As String)
    Console.WriteLine("\n{0}", label)
    If rows.Length <= 0
        Console.WriteLine("no rows found")
        Exit Sub
    End If

    Dim row As DataRow
    Dim column As DataColumn

    For Each row In rows
        For Each column In row.Table.Columns
            Console.Write("\table {0}", row(column))
        Next column
        Console.WriteLine()
    Next row
End Sub

    private static void GetChildRowsFromDataRelation()
    {
        /* For each row in the table, get the child rows using the
        ChildRelations. For each item in the array, print the value
        of each column. */
        DataTable table = CreateDataSet().Tables["Customers"];
        DataRow[] childRows;
        foreach(DataRelation relation in table.ChildRelations)
        {
            foreach(DataRow row in table.Rows)
            {
                PrintRowValues(new DataRow[] {row}, "Parent Row");
                childRows = row.GetChildRows(relation);
                // Print values of rows.
                PrintRowValues(childRows, "child rows");
            }
        }
    }

    public static DataSet CreateDataSet()
    {
        // create a DataSet with one table, two columns
        DataSet dataSet = new DataSet();

        // create Customer table
        DataTable table = new DataTable("Customers");
        dataSet.Tables.Add(table);
        table.Columns.Add("customerId", typeof(int)).AutoIncrement = true;
        table.Columns.Add("name", typeof(string));
        table.PrimaryKey = new DataColumn[] { table.Columns["customerId"] };

        // create Orders table
        table = new DataTable("Orders");
        dataSet.Tables.Add(table);
        table.Columns.Add("orderId", typeof(int)).AutoIncrement = true;
        table.Columns.Add("customerId", typeof(int));
        table.Columns.Add("amount", typeof(double));
        table.PrimaryKey = new DataColumn[] { table.Columns["orderId"] };

        // create relation
        dataSet.Relations.Add(dataSet.Tables["Customers"].Columns["customerId"],
            dataSet.Tables["Orders"].Columns["customerId"]);
    
        // populate the tables
        int orderId = 1;
        for(int customerId=1; customerId<=10; customerId++)
        {
            // add customer record
            dataSet.Tables["Customers"].Rows.Add(
                new object[] { customerId, 
                string.Format("customer{0}", customerId) });
        
            // add 5 order records for each customer
            for(int i=1; i<=5; i++)
            {
                dataSet.Tables["Orders"].Rows.Add(
                    new object[] { orderId++, customerId, orderId * 10 });
            }
        }

        return dataSet;
    }

    private static void PrintRowValues(DataRow[] rows, string label)
    {
        Console.WriteLine("\n{0}", label);
        if(rows.Length <= 0)
        {
            Console.WriteLine("no rows found");
            return;
        }
        foreach(DataRow row in rows)
        {
            foreach(DataColumn column in row.Table.Columns)
            {
                Console.Write("\table {0}", row[column]);
            }
            Console.WriteLine();
        }
    }