1. 查询选修1号课程的学生学号和成绩,并要求对查询结果按成绩的降序排列,如果成绩相同则按学号的升序排列
Select sno,grade
From sc
Where cno =’1’
Order by grade DESE,sno ASC
- 查询缺少了成绩的学生的学号和课程号。
Select sno,cno
From sc
Where grade is null
- 查询每个学生的学号,姓名,选修的课程名,成绩
Select student.sno,sname,cname,grade
From student,sc,course
Where student.sno=sc.cno and sc.cno=course.cno
- 查询每门课程的先行课程的课程名称,学分
Select cpno,ccredit
From course
- 查询每一门课的间接先行课的课程名称
Select first.cname
From course first,course second
Where first.cpno=second.cno
- 查询选修了数据结构课程,且成绩在90分以上的学生姓名,年龄
Select student.sname,sage
From sc,course,student
Where sc.cno=course.cno and student.sno and cname=’数据结构’and grade>=90
- 查询选修了全部课程的学生的姓名
Select sname
From student,sc
Where student.sno=sc.sno
Group by sc.sno,sname
Having count(cno)=7
- 查询至少选修了学号为“201215121”的学生所选修的全部课程的学生学号和姓名
Select distinct sno
From sc ,scx
Where not exists
(select *
From sc,scy
Where scy.sno=’201215121’ and
Not exists
(select *
From sc,scz
Where scz.sno=scx.sno and scz.cno=scy.cno))
- 查询选修了操作系统课程的学生人数
Select count (distinct sno) as zs
From sc,course
Where sc.cno=course.cno and cname=’操作系统’
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