多表查询和数据表的增删改

Question

这类问题
有没有解题思路
或者给个码我试试
主要是没学习多久，对于数据表的应用和命令比较弱。

Answer 1

你得把表结构提供出来

select * from t_student where major_id=(selsect id from t_major where name='云计算技术');


select s.* from t_student s left join t_score c on s.id =c.student_id where c.student_id is null;

select * from t_score where major_id in (selsect id from t_major where name='移动互联应用开发');

insert into t_student(stu_id,stu_name....) values("",""....);


update t_student set major_id = '31601' where stu_name = '王洪';


delete from t_student where stu_birthday<'1999-01-01';