查找不在表里的数据

 

两张表：student  eye

查找出不近视的学生姓名

 

思路1：NOT IN

select a.name

from student as a

where a.id  not  in (select b.studentid from eye as b)

 

思路2：LEFT JOIN

select a.name

from student as a

left join eye as b

on b.studentid is null