I just bought this book and it's great! :D

I worked through the sample website PizzaPrettyQuick(PPQ) and now I want to extend the database to include inventory so I added an Inventory column to the SizeAndPrice table (I know its not practical for this business scenario but it's more for learning purposes really).

In the example, no modifications are made to the database until the checkout is completed as the shopping cart is held in session memory (this is where all the action takes place).

Would I need to take a similar approach to implementing Inventory tracking? By this I mean would I need to store the menu in session memory (kinda like a detached virtual menu) and then every time the shopping cart item quantities are updated I update the quantity available in the virtual menu. Then upon checkout after I add the shopping cart stuff to Orders/OrderDetails I would proceed with updating the SizeAndPrice table with the new inventory values?

Any help in pointing me in the right direction would be much appreciated :)

TIA

You could do it that way. One possible problem is that if you have two concurrent users, the session-based datasets will become out of sync and you'll end up with errors in the database. A solution to this is to run some custom ADO.NET code to execute an UPDATE against the database to remove the item from stock before (or as part of the process of) accepting the order. However, if the user abandons a shopping cart, you'll then have to put the item back in stock. So there are issues to consider both ways.

Once you go beyond simple updates to a single table, you probably need to look at using ADO.NET code and a transaction to perform updates to multiple tables in the database rather than depending on the data source controls to do the updates. This is outside the scope of the book, but it a well-documented process. I suggest looking on the Net for tutorials and examples of using ADO.NET 2.0, or pick up a book that focuses on this topic.

Thanks Alex I am looking into using ADO.NET transactions as per your advice