在MySQL数据库中存储MySQL查询......不好主意？

I've got a shop where users can purchase virtual items, such as one time power-up's and permanent changes to the users account. These purchases potentially alter different fields in different tables, and there's the possibility for a lot of items so i don't want to code a new addition to a PHP file every time i want to add a new product.I've got a shop where users can purchase virtua