【Advanced SQL-1 】大连理工软件学院_数据库第四次上机答案

这次还是之前的数据库，以下五道题对应教材第三章结尾部分

Using the university schema that you have write the following queries. In some cases you might need to insert extra data to show the effect of a particular feature. 

//有些时候你需要修改数据库

第一题：

Insert each student as an instructor of department ‘拳脚学院’, with salary=40000 

插入操作，没什么好说的，注意插之前判断一下教师表里是否已经存在这个人了

insert into instructor
select S.ID, S.name, '拳脚学院', 40000
from student S
where S.ID not in ( select ID from instructor );

第二题：

Now delete all the newly added "