Thanks to Bob Ceccarelli.
This example uses customer, order, and order detail classes to manage the data. A customer object contains references to any number of order objects. Each order contains references to order detail objects.
Change the value of DB_PATH in the .bas file so it points to the Northwind database that came with your copy of Visual Basic.
When you select a new customer, the program loads the customer's orders. When you select one of the orders, the program displays its order items in the DataGrid. See the code for details.