MYSQL查询之多表查询select嵌套的三种形式。

一、（having，group by，select嵌套放在select里）

          可参考 https://www.jianshu.com/p/8b135d373df1

二、(not in，distinct去重，select嵌套放在where里）

表的内容如下：

实现功能：查询没学过"张三"老师授课的同学的信息

实现语句：

 SELECT student.s_id,student.s_name FROM student WHERE s_id
 not in (SELECT distinct( score.s_id) FROM score,course,teacher WHERE score.c_id=course.
c_id AND course.t_id=teacher.t_id AND teacher.t_name='张三');

三，(select嵌套放在from里）表可参照2

实现功能：查询学过编号为"01"并且也学过编号为"02"的课程的同学的信息

实现语句：

SELECT *from (SELECT s_id,s_score from score WHERE score.c_id
="01")as t1,(SELECT s_id,s_score from score WHERE score.c_id="02")
as t2 WHERE t1.s_id=t2.s_id