sql语句 练习题

sql 语句练习题

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1、查询学生的选课情况，要求显示学号、姓名、课程号
SELECT a.sno,a.sname,b.cno from dbo.student as a
right join dbo.sc as b on a.sno= b.sno


2、查询‘法学院’学生的修课情况，要求列出学生的名字、所修课的课程号和成绩。
select a.sname,b.cno,b.grade from dbo.student as a
inner join dbo.sc as b on a.sno = b.sno
where sdept='法学院'


3、查询''计算机科学学院''选修了‘数据库及应用’课程的学生的修课成绩，要求列出学生姓名、课程名和成绩。
select a.sname,c.cname,b.grade from dbo.student as a
inner join dbo.sc as b on a.sno = b.sno
inner join dbo.course as c on b.cno= c.cno 
where a.sdept='计算机科学学院' and c.cname='数据库及应用'


4、查询所有修了‘军事理论’课程的学生的修课情况，要求列出学生姓名和所在的院系。(多表的连接)
select a.sname,a.sdept from dbo.student as a
inner join dbo.sc as b on a.sno = b.sno
inner join dbo.course as c on b.cno= c.cno 
where c.cname='军事理论'


5、查询学生的修课情况，包括修了课程的学生和没有修课的学生,要求显示学号、姓名、课程号。
select a.sno,a.sname,b.cno from dbo.student as a
left join dbo.sc as b on a.sno = b.sno
left join dbo.course as c on b.cno= c.cno 


6、查询哪些学生没有选课，要求列出学号、姓名和所在系。
select a.sno,a.sname,a.sdept from dbo.student as a
left join dbo.sc as b on a.sno = b.sno
left join dbo.course as c on b.cno= c.cno 
where c.cname is null


7、用子查询查询与‘路飞’在同一个院系的学生的学号、姓名、院系。
select * from dbo.student as a
where a.sname !='路飞' and a.sdept in(select b.sdept  from dbo.student as b where b.sname ='路飞')


8、用子查询找出平均成绩为大于80分的学生的学号、姓名、院系。
select s.sno,s.sname,s.sdept from dbo.student  as s
where s.sno in (select b.sno from dbo.sc as b group by b.sno having avg(b.grade)>80 )


9、用子查询查询修了‘A008’课程且成绩高于此课程的平均成绩的学生所有数据。
select * from dbo.student as s
inner join dbo.sc as t on s.sno = t.sno  
inner join dbo.course as c on t.cno=c.cno
where t.cno='A008'
and t.grade>(select avg(v.grade) from dbo.course as t 
inner join dbo.sc as v on t.cno=v.cno
where t.cno='A008')


10、查询‘’医学院‘’考试成绩最高的学生的学号。
法一：
select top 1 a.sno,max(grade) from dbo.student as a
inner join dbo.sc as b on a.sno = b.sno
where a.sdept='医学院' 
group by a.sno
order by max(grade)desc

法二：
select top 1 st.sno
from student st left join sc s on st.sno=s.sno where st.sdept='医学院'
order by s.grade desc