课程设计总结，数据库系列的，提供给做完程序后需要写总结的同学-Summary curriculum design, database series, and made available to the finished program required students to write summary

这是我在学习sql时，发现非常容易出错的问题。平时都把点点滴滴记录下来了。便于在写语言时，出错后对照下这些语法，很快就能解决问题-This is my sql in the study, we found that the problem is very easy to make mistakes. Usually regarded bits and pieces recorded. Easy to write language, gr