本系统的设计模式模拟是书店的图书销售情况，经过充分地系统调研，发现本系统应包括图书信息，客户，营销信息，销售统计信息，退货信息。除此之外应该还包括操作员信息-The system design model simulations of the books in bookstores sales, after full system research and found that the system should include the book information, customers, marketing information, sales statistics, returns information. In addition the operator should also include information