1. 查询“001”课程比“002”课程成绩高的所有学生的学号；
2. 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；
3. 查询平均成绩大于60分的同学的学号和平均成绩；
4. 查询所有同学的学号、姓名、选课数、总成绩；
5. 查询姓“李”的老师的个数；
6. 查询没学过“叶平”老师课的同学的学号、姓名；
7. 查询学过“001”并且也学过编号“002”课程的同学的学号、姓名；
8. 查询学过“叶平”老师所教的所有课的同学的学号、姓名；
9. 查询所有课程成绩小于60分的同学的学号、姓名；
10. 查询没有学全所有课的同学的学号、姓名；
11. 查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名；
12. 查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名；
13. 把“SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩；
???
update SC set score=(select avg(SC_2.score)
from SC SC_2
where SC_2.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname=‘叶平’);
14. 查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名；
15. 删除学习“叶平”老师课的SC表记录；
16、向SC表中插入一些记录，这些记录要求符合以下条件：没有上过编号“003”课程的同学学号、2、号课的平均成绩；
???
Insert SC select S#,‘002’,(Select avg(score)
from SC where C#=‘002’) from Student where S# not in (Select S# from SC where C#=‘002’);
17. 按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩，按如下形式显示： 学生ID，数据库，企业管理，英语，有效课程数，有效平均分
18. 查询各科成绩最高和最低的分：以如下形式显示：课程ID，最高分，最低分
19. 按各科平均成绩从低到高和及格率的百分数从高到低顺序
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），OO&UML （003），数据库（004）
21. 查询不同老师所教不同课程平均分从高到低显示
SELECT max(Z.T#) AS 教师ID,MAX(Z.Tname) AS 教师姓名,C.C# AS 课程ＩＤ,MAX(C.Cname) AS 课程名称,AVG(Score) AS 平均成绩
FROM SC AS T,Course AS C ,Teacher AS Z
where T.C#=C.C# and C.T#=Z.T#
GROUP BY C.C#
ORDER BY AVG(Score) DESC
22. 查询如下课程成绩第 3 名到第 6 名的学生成绩单：企业管理（001），马克思（002），UML （003），数据库（004）
[学生ID],[学生姓名],企业管理,马克思,UML,数据库,平均成绩
SELECT DISTINCT top 3
SC.S# As 学生学号,
Student.Sname AS 学生姓名 ,
T1.score AS 企业管理,
T2.score AS 马克思,
T3.score AS UML,
T4.score AS 数据库,
ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 总分
FROM Student,SC LEFT JOIN SC AS T1
ON SC.S# = T1.S# AND T1.C# = '001’
LEFT JOIN SC AS T2
ON SC.S# = T2.S# AND T2.C# = '002’
LEFT JOIN SC AS T3
ON SC.S# = T3.S# AND T3.C# = '003’
LEFT JOIN SC AS T4
ON SC.S# = T4.S# AND T4.C# = '004’
WHERE student.S#=SC.S# and
ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
NOT IN
(SELECT
DISTINCT
TOP 15 WITH TIES
ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
FROM sc
LEFT JOIN sc AS T1
ON sc.S# = T1.S# AND T1.C# = 'k1’
LEFT JOIN sc AS T2
ON sc.S# = T2.S# AND T2.C# = 'k2’
LEFT JOIN sc AS T3
ON sc.S# = T3.S# AND T3.C# = 'k3’
LEFT JOIN sc AS T4
ON sc.S# = T4.S# AND T4.C# = 'k4’
ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);
23. 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],[ <60]
SELECT SC.C# as 课程ID, Cname as 课程名称
,SUM(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85]
,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 - 70]
,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 - 60]
,SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) AS [60 -]
FROM SC,Course
where SC.C#=Course.C#
GROUP BY SC.C#,Cname;
24. 查询学生平均成绩及其名次
SELECT 1+(SELECT COUNT( distinct 平均成绩)
FROM (SELECT S#,AVG(score) AS 平均成绩
FROM SC
GROUP BY S#
) AS T1
WHERE 平均成绩 > 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)
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 ,Student
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 count(Ssex) as 男生人数 from Student group by Ssex having Ssex=‘男’;
Select count(Ssex) as 女生人数 from Student group by Ssex having Ssex=‘女’；
29. 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. 1981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 <60;
35. 查询所有学生的选课情况
SELECT SC.S#,SC.C#,Sname,Cname
FROM SC,Student,Course
where SC.S#=Student.S# and SC.C#=Course.C# ;
36. 查询任何一门课程成绩在70分以上的姓名、课程名称和分数
SELECT distinct student.S#,student.Sname,SC.C#,SC.score
FROM student,Sc
WHERE SC.score>=70 AND SC.S#=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 <60 order by C# ;
38. 查询课程编号为003且课程成绩在80分以上的学生的学号和姓名
select SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>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 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# <>B.C# ;
43. 查询每门功成绩最好的前两名
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 2 score
FROM SC
WHERE t1.C#= C#
ORDER BY score DESC
)
ORDER BY t1.C#;
44. 统计每门课程的学生选修人数（超过10人的课程才统计）。要求输出课程号和选修人数，查询结果按人数降序排列，查询结果按人数降序排列，若人数相同，按课程号升序排列
select C# as 课程号,count() as 人数
from sc
group by C#
order by count() desc,c#
45. 检索至少选修两门课程的学生学号
select S#
from sc
group by s#
having count() > = 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 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 <60 group by S# having count()>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#='004’and score <60 order by score desc;
50. 删除“002”同学的“001”课程的成绩
delete from Sc where S#='001’and C#=‘001’;