这是一个书籍管理应用程序。系统要完成对书籍的管理，应包括类目管理：书籍的增加和删除；借阅管理：借出和还入；信息的查询等功能。-This is a book management application. To complete the system of management books, including Category Management : books on the increase and deleted; Readers management : the lending and also means; Information inquiries, and other functions.