从数据库中取出有关价格信息，再把这些信息返回给收银台。同时把该收银台的销售总量和有关种类商品的剩余量以及该持卡顾客的消费情况交数据库存储以供查询。-Removed from the database of information about price, then that information back to the cashier. While the total sales of the cash register and the remaining amount and type of merchandise the customer' s consumption of the card to pay for the query database storage.