ian jenkins

Whilst recently implementing a discount system for an e-commerce site I needed to apply the biggest discount should there be a product which was eligible for more than one discount. As the system allowd x for y type discounts I needed to order my results with x-y so I could find out which of the x for y discounts was the best value for money.

In order to do this I used something like the following SQL:

SELECT discount FROM discounts WHERE ABS(x_value - y_value) DESC

With thanks to:
http://www.bradino.com/mysql/order-by-numeric-difference/