根据要求写SQL 语句

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

 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.score>b.score and a.s#=b.s#;

 查询平均成绩大于60 分的同学的学号和平均成绩；

select S#,avg(score)

from sc

group by S# having avg(score) >60;

 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

 查询姓“李”的老师的个数；

select count(distinct(Tname))

from Teacher

where Tname like '李%';

 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');

 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 Student.S#=SC.S# and SC.C#='001'and

exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');

 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(SC.C#)=(select count(C#) from Course,Teacher

where Teacher.T#=Course.T# and Tname='叶平'));

 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.S# and C#='001') S_2 where score2 <score;

 查询所有课程成绩小于60 分的同学的学号、姓名；

select S#,Sname

from Student

where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);

 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#) <(select

count(C#) from Course);

 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；

select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where

S#='1001';

 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；

select distinct SC.S#,Sname

from Student,SC

where Student.S#=SC.S# and C# in (select C# from SC where S#='001');

 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');

 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；

select S# from SC where C# in (select C# from SC where S#='1002')

group by S# having count(*)=(select count(*) from SC where S#='1002');

 删除学习“叶平”老师课的SC 表记录；

Delect SC

from course ,Teacher

where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';

 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002

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#='003');

 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

SELECT S# as 学生ID

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 数据库

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英语

,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩

FROM SC AS t

GROUP BY S#

ORDER BY avg(t.score)

 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

SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分

FROM SC L ,SC AS R

WHERE L.C# = R.C# and

L.score = (SELECT MAX(IL.score)

FROM SC AS IL,Student AS IM

WHERE L.C# = IL.C# and IM.S#=IL.S#

GROUP BY IL.C#)

AND

R.Score = (SELECT MIN(IR.score)

FROM SC AS IR

WHERE R.C# = IR.C#

GROUP BY IR.C#

);

 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

SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩

,100 * SUM(CASE WHEN isnull(score,0)>=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 WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC

 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）

SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1

ELSE 0 END) AS 企业管理平均分

,100 * SUM(CASE WHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '001' THEN 1 ELSE 0 END) AS 企业管理及格百分数

,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1

ELSE 0 END) AS 马克思平均分

,100 * SUM(CASE WHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '002' THEN 1 ELSE 0 END) AS 马克思及格百分数

,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/SUM(CASE C# WHEN '003' THEN 1

ELSE 0 END) AS UML 平均分

,100 * SUM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '003' THEN 1 ELSE 0 END) AS UML 及格百分数

,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1

ELSE 0 END) AS 数据库平均分

,100 * SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '004' THEN 1 ELSE 0 END) AS 数据库及格百分数

FROM SC

 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

 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);

 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;

 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;

 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#;

 查询每门课程被选修的学生数

select c#,count(S#) from sc group by C#;

 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;

 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'；

 查询姓“张”的学生名单

SELECT Sname FROM Student WHERE Sname like '张%';

 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;;

 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';

 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 ;

 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;

 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;

 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# ;

 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#;

 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# ;

 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';

 求选了课程的学生人数

select count(*) from sc;

 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# );

 查询各个课程及相应的选修人数

select count(*) from sc group by C#;

 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# ;

 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#;

 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#

 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

 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#)

 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');

 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#;

 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;

 删除“002”同学的“001”课程的成绩

delete from Sc where S#='001'and C#='001'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

 

 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.score>b.score and a.s#=b.s#;

 

 查询平均成绩大于60 分的同学的学号和平均成绩；

 

select S#,avg(score)

 

from sc

 

group by S# having avg(score) >60;

 

 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

 

 查询姓“李”的老师的个数；

 

select count(distinct(Tname))

 

from Teacher

 

where Tname like '李%';

 

 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');

 

 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 Student.S#=SC.S# and SC.C#='001'and

 

exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');

 

 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(SC.C#)=(select count(C#) from Course,Teacher

 

where Teacher.T#=Course.T# and Tname='叶平'));

 

 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.S# and C#='001') S_2 where score2 <score;

 

 查询所有课程成绩小于60 分的同学的学号、姓名；

 

select S#,Sname

 

from Student

 

where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);

 

 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#) <(select

 

count(C#) from Course);

 

 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；

 

select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where

 

S#='1001';

 

 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；

 

select distinct SC.S#,Sname

 

from Student,SC

 

where Student.S#=SC.S# and C# in (select C# from SC where S#='001');

 

 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');

 

 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；

 

select S# from SC where C# in (select C# from SC where S#='1002')

 

group by S# having count(*)=(select count(*) from SC where S#='1002');

 

 删除学习“叶平”老师课的SC 表记录；

 

Delect SC

 

from course ,Teacher

 

where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';

 

 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002

 

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#='003');

 

 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

 

SELECT S# as 学生ID

 

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 数据库

 

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理

 

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英语

 

,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩

 

FROM SC AS t

 

GROUP BY S#

 

ORDER BY avg(t.score)

 

 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

 

SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分

 

FROM SC L ,SC AS R

 

WHERE L.C# = R.C# and

 

L.score = (SELECT MAX(IL.score)

 

FROM SC AS IL,Student AS IM

 

WHERE L.C# = IL.C# and IM.S#=IL.S#

 

GROUP BY IL.C#)

 

AND

 

R.Score = (SELECT MIN(IR.score)

 

FROM SC AS IR

 

WHERE R.C# = IR.C#

 

GROUP BY IR.C#

 

);

 

 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

 

SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩

 

,100 * SUM(CASE WHEN isnull(score,0)>=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 WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC

 

 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）

 

SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1

 

ELSE 0 END) AS 企业管理平均分

 

,100 * SUM(CASE WHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

 

C# = '001' THEN 1 ELSE 0 END) AS 企业管理及格百分数

 

,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1

 

ELSE 0 END) AS 马克思平均分

 

,100 * SUM(CASE WHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

 

C# = '002' THEN 1 ELSE 0 END) AS 马克思及格百分数

 

,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/SUM(CASE C# WHEN '003' THEN 1

 

ELSE 0 END) AS UML 平均分

 

,100 * SUM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

 

C# = '003' THEN 1 ELSE 0 END) AS UML 及格百分数

 

,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1

 

ELSE 0 END) AS 数据库平均分

 

,100 * SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

 

C# = '004' THEN 1 ELSE 0 END) AS 数据库及格百分数

 

FROM SC

 

 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

 

 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);

 

 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;

 

 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;

 

 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#;

 

 查询每门课程被选修的学生数

 

select c#,count(S#) from sc group by C#;

 

 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;

 

 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'；

 

 查询姓“张”的学生名单

 

SELECT Sname FROM Student WHERE Sname like '张%';

 

 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;;

 

 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';

 

 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 ;

 

 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;

 

 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;

 

 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# ;

 

 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#;

 

 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# ;

 

 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';

 

 求选了课程的学生人数

 

select count(*) from sc;

 

 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# );

 

 查询各个课程及相应的选修人数

 

select count(*) from sc group by C#;

 

 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# ;

 

 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#;

 

 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#

 

 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

 

 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#)

 

 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');

 

 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#;

 

 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;

 

 删除“002”同学的“001”课程的成绩

delete from Sc where S#='001'and C#='001'

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

 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.score>b.score and a.s#=b.s#;

 查询平均成绩大于60 分的同学的学号和平均成绩；

select S#,avg(score)

from sc

group by S# having avg(score) >60;

 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

 查询姓“李”的老师的个数；

select count(distinct(Tname))

from Teacher

where Tname like '李%';

 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');

 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 Student.S#=SC.S# and SC.C#='001'and

exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');

 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(SC.C#)=(select count(C#) from Course,Teacher

where Teacher.T#=Course.T# and Tname='叶平'));

 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.S# and C#='001') S_2 where score2 <score;

 查询所有课程成绩小于60 分的同学的学号、姓名；

select S#,Sname

from Student

where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);

 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#) <(select

count(C#) from Course);

 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；

select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where

S#='1001';

 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；

select distinct SC.S#,Sname

from Student,SC

where Student.S#=SC.S# and C# in (select C# from SC where S#='001');

 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');

 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；

select S# from SC where C# in (select C# from SC where S#='1002')

group by S# having count(*)=(select count(*) from SC where S#='1002');

 删除学习“叶平”老师课的SC 表记录；

Delect SC

from course ,Teacher

where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';

 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002

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#='003');

 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

SELECT S# as 学生ID

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 数据库

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英语

,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩

FROM SC AS t

GROUP BY S#

ORDER BY avg(t.score)

 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

SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分

FROM SC L ,SC AS R

WHERE L.C# = R.C# and

L.score = (SELECT MAX(IL.score)

FROM SC AS IL,Student AS IM

WHERE L.C# = IL.C# and IM.S#=IL.S#

GROUP BY IL.C#)

AND

R.Score = (SELECT MIN(IR.score)

FROM SC AS IR

WHERE R.C# = IR.C#

GROUP BY IR.C#

);

 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

SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩

,100 * SUM(CASE WHEN isnull(score,0)>=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 WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC

 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）

SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1

ELSE 0 END) AS 企业管理平均分

,100 * SUM(CASE WHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '001' THEN 1 ELSE 0 END) AS 企业管理及格百分数

,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1

ELSE 0 END) AS 马克思平均分

,100 * SUM(CASE WHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '002' THEN 1 ELSE 0 END) AS 马克思及格百分数

,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/SUM(CASE C# WHEN '003' THEN 1

ELSE 0 END) AS UML 平均分

,100 * SUM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '003' THEN 1 ELSE 0 END) AS UML 及格百分数

,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1

ELSE 0 END) AS 数据库平均分

,100 * SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN

C# = '004' THEN 1 ELSE 0 END) AS 数据库及格百分数

FROM SC

 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

 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);

 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;

 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;

 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#;

 查询每门课程被选修的学生数

select c#,count(S#) from sc group by C#;

 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;

 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'；

 查询姓“张”的学生名单

SELECT Sname FROM Student WHERE Sname like '张%';

 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;;

 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';

 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 ;

 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;

 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;

 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# ;

 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#;

 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# ;

 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';

 求选了课程的学生人数

select count(*) from sc;

 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# );

 查询各个课程及相应的选修人数

select count(*) from sc group by C#;

 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# ;

 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#;

 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#

 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

 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#)

 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');

 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#;

 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;

 删除“002”同学的“001”课程的成绩

delete from Sc where S#='001'and C#='001'