A good and flexible database schema illustrating e-commerce products and their rates management is required.
I agree with Chris Roberts, OSCommerce is a good place to start as well as DatabaseAnswers.org.
Hope that helps.
I'm sure there are many examples about - try looking at some open source shopping cart tools.
As a general point, though, I think there are so many ways that a product pricing and discount / gift voucher system could work that finding a database schema that works for every possibility is unlikely!
Perhaps you can save yourself some heartache by refining the requirements a little?
来源：https://stackoverflow.com/questions/320211/is-there-a-standard-e-commerce-database-schema-to-apply-the-discounts-taxes-gift