假设某超市购物信息主要包括：会员编号，会员名，商品编号，商品名，商品价格，商品数量，商品日期等，本系统应能对这些基本信息进行管理，具有会员信息录入、查看、保存至文件、从文件中读出、增加购买信息，修改购买信息，删除购买信息，按商品项查询。-Suppose a supermarket shopping information include: User ID, member name, product number, product name, product price, quantity, product, etc., the system should be able to manage these basic information, membership information input, view, save to files, read from the file, add the purchase information, purchase information to modify, delete, purchase information, by commodity item queries.