有学生关系表S(学号S,学生姓名SN,所属系名SD),课程关系表C(课程号C,课程名CN,先行课号码PC),学生选课表D(学号S,课程号C,学习成绩G)
试试:
select t1.学号S,t1.课程号C,t1.学习成绩G
from 学生选课表D t1,
(select 学号S from
(select 课程号C,count(1) as cnt1 from 课程关系表C group by 课程号C) a,
(select 学号S,count(课程号C) as cnt2 from 学生选课表D group by 学号S) b
where a.cnt1 =b.cnt2 )) t2
where t1.学号S=t2.学号S
and t1.学习成绩G>=85
试试:
select t1.学号S,t1.课程号C,t1.学习成绩G
from 学生选课表D t1,
(select 学号S from
(select 课程号C,count(1) as cnt1 from 课程关系表C group by 课程号C) a,
(select 学号S,count(课程号C) as cnt2 from 学生选课表D group by 学号S) b
where a.cnt1 =b.cnt2 )) t2
where t1.学号S=t2.学号S
and t1.学习成绩G>=85
解决方案 »
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