Web Listing 7: Updating the Hierarchical DataSet

Private Sub UpdateHierarchy()
        Using TransScope As New System.Transactions.TransactionScope
            Try
                ' Add parents first, then children
                ' Delete children first, then parents
                ' Use the Select method to return an array 
                ' of rows to be updated or added
                Dim dtCust As CustomerDataSet.GetCustomersByStateDataTable = _
                    Me.CustomerDataSet.Tables("GetCustomersByState")
                ' Add or change first tier parent (Customers)
                Me.GetCustomersByStateTableAdapter.Update(dtCust.Select("", "", _
                            DataViewRowState.Added Or  _
                            DataViewRowState.ModifiedCurrent))
                ' Add or change second tier parent (Orders)
                Dim dtOrder As _ 
                    CustomerDataSet.GetOrdersByCustomerDataTable = _
                    CustomerDataSet.Tables("GetOrdersByCustomer")
                Me.GetOrdersByCustomerTableAdapter.Update(dtOrder.Select("", "", _
                    DataViewRowState.Added Or _
                    DataViewRowState.ModifiedCurrent))
                ' Now Add, Change or Delete third-tier children
                Dim dtItems As _
                  CustomerDataSet.GetItemsByCustomerOrderDataTable = _
                  Me.CustomerDataSet.Tables("GetItemsByCustomerOrder")
                Me.GetItemsByCustomerOrderTableAdapter.Update(dtItems)
                ' Now it's safe to delete the second-tier children (parents to third tier) (Orders)
                Me.GetOrdersByCustomerTableAdapter.Update(dtOrder.Select("", "", _
                    DataViewRowState.Deleted))
                ' Now it's safe to delete the parent (Customers)
                Me.GetCustomersByStateTableAdapter.Update(dtCust.Select("", "", _
                    DataViewRowState.Deleted))
                TransScope.Complete()
                MsgBox("Update succeeded...")
            Catch ex As Exception
                MsgBox(ex.ToString)
            End Try
        End Using
    End Sub