All,

I am putting together a simple shopping cart application. As a business requirement, customers cannot order more products than are currently in stock (No Back Ordering).

This application has an Order object which contains LineItem objects. Each line item references a Product. Each of these objects has its own underlying table. The "Product" table contains product information as well as the products quantity. The LineItem object/table contains the quantity of the product that gets ordered by the customer.

Where/when should the remaining inventory get calculated? If I use hibernate, it sounds like I would have to retrieve all of the lineItems for a particular product and sum up the ordered quantities in each lineItem and subtract this number from the products quantity to determine the number available. Does this sound right? Is there a better way to do this?

Regards,

Joshua

just use a HQL query?