1、基本信息 Student(S#,Sname,Sage,Ssex) 学生表 Course(C#,Cname,T#) 课程表 SC(S#,C#,score) 成绩表 Teacher(T#,Tname) 教师表问题： 1、查询“001”课程比“002”课程成绩高的所有学生的学号； select a.S# from (select s#,score from SC where C#=001) a,(select s#,score from SC where C#=002) b where a.scoreb.score and a.s#=b.s#; 2、查询平均成绩大于 60 分的同学的学号和平均成绩；
2、 select S#,avg(score) from sc group by S# having avg(score) 60; 3、查询所有同学的学号、姓名、选课数、总成绩； select Student.S#,Student.Sname,count(SC.C#),sum(score) from Student left Outer join SC on Student.S#=SC.S# group by Student.S#,Sname 4、查询姓“李”的老师的个数； select count(distinct(Tname) from Teacher where Tname like 李%;
3、 5、查询没学过“叶平”老师课的同学的学号、姓名； select Student.S#,Student.Sname from Student where S# not in (select distinct( SC.S#) from SC,Course,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname=叶平); 6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名； select Student.S#,Student.Sname from Student,SC where Stude
4、nt.S#=SC.S# and SC.C#=001and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#=002); 7、查询学过“叶平”老师所教的所有课的同学的学号、姓名； select S#,Sname from Student where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname=叶平 group by S# having count(S
5、C.C#)=(select count(C#) from Course,Teacher where Teacher.T#=Course.T# and Tname=叶平); 8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名； Select S#,Sname from (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#=002) score2 from Student,SC where Student.S#=SC
6、.S# and C#=001) S_2 where score2 60); 10、查询没有学全所有课的同学的学号、姓名； select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# group by Student.S#,Student.Sname having count(C#) =60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分数 FROM SC T,Course where t.C#=course.C# GROUP BY t.C# ORDER BY 100 * SUM(CASE
7、WHEN isnull(score,0)=60 THEN 1 ELSE 0 END)/COUNT(*) DESC 20、查询如下课程平均成绩和及格率的百分数(用“1 行“显示): 企业管理（001），马克思（002），OO23、统计列印各科成绩,各分数段人数:课程 ID,课程名称,100-85,85-70,70-60, T2.平均成绩) as 名次, S# as 学生学号,平均成绩 FROM (SELECT S#,AVG(score) 平均成绩 FROM SC GROUP BY S# ) AS T2 ORDER BY 平均成绩 desc; 25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
8、 SELECT t1.S# as 学生 ID,t1.C# as 课程 ID,Score as 分数 FROM SC t1 WHERE score IN (SELECT TOP 3 score FROM SC WHERE t1.C#= C# ORDER BY score DESC ) ORDER BY t1.C#; 26、查询每门课程被选修的学生数 select c#,count(S#) from sc group by C#; 27、查询出只选修了一门课程的全部学生的学号和姓名 select SC.S#,Student.Sname,count(C#) AS 选课数 from SC ,Stude
9、nt where SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1; 28、查询男生、女生人数 Select Ssex, count(Ssex) as 人数from Studentgroup by Ssex29、查询姓“张”的学生名单 SELECT Sname FROM Student WHERE Sname like 张%; 30、查询同名同性学生名单，并统计同名人数 select Sname,count(*) from Student group by Sname having count(*)1; 31、1
10、981 年出生的学生名单(注： Student 表中 Sage 列的类型是 datetime) select Sname, CONVERT(char (11),DATEPART(year,Sage) as age from student where CONVERT(char(11),DATEPART(year,Sage)=1981; 32、查询每门课程的平均成绩，结果按平均成绩升序排列，平均成绩相同时，按课程号降序排列 Select C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ; 33、查询平均成绩大于 85 的
11、所有学生的学号、姓名和平均成绩 select Sname,SC.S# ,avg(score) from Student,SC where Student.S#=SC.S# group by SC.S#,Sname having avg(score)85; 34、查询课程名称为“数据库”，且分数低于 60 的学生姓名和分数 Select Sname,isnull(score,0) from Student,SC,Course where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname=数据库and score =70 AND SC.S#
12、=student.S#; 37、查询不及格的课程，并按课程号从大到小排列 select c# from sc where scor e 80 and C#=003; 39、求选了课程的学生人数 select count(*) from sc; 40、查询选修“叶平”老师所授课程的学生中，成绩最高的学生姓名及其成绩 select Student.Sname,score from Student,SC,Course C,Teacher where Student.S#=SC.S# and SC.C#=C.C# and C.T#=Teacher.T# and Teacher.Tname=叶平 and
13、 SC.score=(select max(score)from SC where C#=C.C# ); 41、查询各个课程及相应的选修人数 select count(*) from sc group by C#; 42、查询不同课程成绩相同的学生的学号、课程号、学生成绩 select distinct A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# = 2 46、查询全部学生都选修的课程的课程号和课程名 select C#,Cname from Course where C# in (select c# from sc
14、group by c#) 47、查询没学过“叶平”老师讲授的任一门课程的学生姓名 select Sname from Student where S# not in (select S# from Course,Teacher,SC where Course.T#=Teacher.T# and SC.C#=course.C# and Tname=叶平); 48、查询两门以上不及格课程的同学的学号及其平均成绩 select S#,avg(isnull(score,0) from SC where S# in (select S# from SC where score 2)group by S#; 49、检索“004”课程分数小于 60，按分数降序排列的同学学号 select S# from SC where C#=004and score 60 order by score desc; 50、删除“002”同学的“001”课程的成绩 delete from Sc where S#=001and C#=001;
