学生表:students(sid,name,age)
课程表:kecheng(kid,kname,tid)
成绩表:chengji(sid,kid,score)
教师表:teacher(tid,name)
要求:查找出所有课程成绩分数都小于60的学生的sid,name!
课程表:kecheng(kid,kname,tid)
成绩表:chengji(sid,kid,score)
教师表:teacher(tid,name)
要求:查找出所有课程成绩分数都小于60的学生的sid,name!
where sid=(select sid from chengji where score < 60)
from students a,chengji b
where a.sid=b.sid
and not exist (select 1 from chengji where score>60 and sid=a.sid)
group by a.sid
这个可以哟。先按sid把成绩group一把,把最大分都小于60分的滤掉,也就OK了正解
from students
where sid not in
(select sid from chengji where score>=60)