当条形码扫描时，系统从商品表中扫描出物品的基本信息，扫描出的物品首先进入销售临时表。当确认无误时，单击购买，购买的同时，进入销售详单和销售表，销售表生成一个销售号，销售详单参照销售表的销售单号。与此同时，激活触发器，同时减少库存表中的相应商品的数目，即减少了超市仓库中的相应物品的数量-When the bar code scanning, the system scan from the merchandise table items of basic information, scan items the first to enter the sale of a temporary table. When the confirmation, click buy, buy at the same time, into the sale of a single detail and sales table, sales table to generate a sales number, the sales details of a single reference to the sale of a single number of the sales table. At the same time, the activation of the trigger, while reducing the number of the corresponding goods in the inventory table, or a decrease in the number of items in the supermarket warehouse