说明：  数据库设计指南,主要讲解如何进行数据库的设计,如何设计表,如何设计主键.索引等.其实很多人忽视了,数据库的设计是非常重要的.数据库设计得好不但可以少写很多代码,而且可以少费很大脑力!
(database design guidelines, explain how the database design, how to design a table, how to design the main keys. Indexing. In fact, many people ignored, the database design is very important. Database design is not only good to write a lot less code, but can cost much less intellectual !)