说明：  本资料是mysql 某培训机构的课件，还有相应的学习笔记，用来进行简单的入门，非常有用，之前需要用到一段数据库，所以学习了下，非常适合初学者入门学习，学习效率好。
(This information is a MySQL training organization courseware, and the corresponding learning notes, used for a simple introduction, very useful, before the need to use a database, so learning, it is very suitable for beginners to learn, good learning efficiency.)