题目：旅行代理数据库设计

初始条件：

一个旅行代理机构希望为他的消费者假日登记行为建立一个数据库。消费者在公司登记假期旅行。每个假期活动中一般都有飞机航班和食宿。在接受登记后，假日旅游的账单就会发给用户。

-Topic: travel agents, database design, the initial conditions: a travel agency wants to register his holiday behavior of consumers to establish a database. Consumer holiday travel in the company register. Each holiday activities normally have flights and accommodation. During registration, holiday travel will be distributed to customers bills.