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1、表Student(Sid,Sname,Sage,Ssex) 学生表CREATE TABLE student ( sid varchar(10) NOT NULL, sName varchar(20) DEFAULT NULL, sAge datetime DEFAULT 1980-10-12 23:12:36, sSex varchar(10) DEFAULT NULL, PRIMARY KEY (sid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; Course(Cid,Cname,Tid) 课程表CREATE TABLE course ( cid varch
2、ar(10) NOT NULL, cName varchar(10) DEFAULT NULL, tid int(20) DEFAULT NULL, PRIMARY KEY (cid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;SC(Sid,Cid,score) 成绩表CREATE TABLE sc ( sid varchar(10) DEFAULT NULL, cid varchar(10) DEFAULT NULL, score int(10) DEFAULT NULL 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - -
3、-第 1 页，共 14 页) ENGINE=InnoDB DEFAULT CHARSET=utf8;Teacher(Tid,Tname) 教师表CREATE TABLE taacher ( tid int(10) DEFAULT NULL, tName varchar(10) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8; 数据： MySQL insert into taacher(tid,tName) values (1, 李老师),(2, 何以琛),(3, 叶平); insert into student(sid,sName,sAge,
4、sSex) values (1001, 张三丰 ,1980-10-12 23:12:36,男),(1002, 张无极 ,1995-10-12 23:12:36, 男),(1003, 李奎,1992-10-12 23:12:36, 女),(1004, 李元宝 ,1980-10-12 23:12:36, 女),(1005, 李世明,1981-10-12 23:12:36,男),(1006, 赵六,1986-10-12 23:12:36,男),(1007, 田七,1981-10-12 23:12:36,女); insert into sc(sid,cid,score) values (1,001,8
5、0),(1,002,60),(1,003,75),(2,001,85),(2,002,70),(3,004,100),(3,001,90),(3,002,55),(4,002,65),(4,003,60); insert into course(cid,cName,tid) values (001, 企业管理 ,3),(002, 马克思 ,3),(003,UML,2),(004,数据库 ,1),(005,英语,1); 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.Sid from (select sid,score from SC where Ci
6、d=001) a,(select sid,score from SC where Cid=002) b where a.scoreb.score and a.sid=b.sid; 2、查询平均成绩大于60 分的同学的学号和平均成绩; 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 2 页，共 14 页select Sid,avg(score) from sc group by Sid having avg(score) 60; 3、查询所有同学的学号、选课数、总成绩; select Student.Sid,Student.Sname,count(S
7、C.Cid),sum(score) from Student left Outer join SC on Student.Sid=SC.Sid group by Student.Sid,Sname 4、查询姓 “ 李” 的老师的个数 ; select count(distinct(Tname) from Teacher where Tname like 李%; 5、查询没学过 “ 叶平” 老师课的同学的学号、 ; select Student.Sid,Student.Sname from Student where Sid not in (select distinct( SC.Sid) fr
8、om SC,Course,Teacher where SC.Cid=Course.Cid and Teacher.Tid=Course.Tid 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、 ; select Student.Sid,Student.Sname from Student,SC where Student.Sid=SC.Sid and SC.Cid=001and exists( Select * from SC as SC_2 where SC_2.Sid=SC.Sid and SC_2.Cid=002); 7
9、、查询学过 “ 叶平” 老师所教的所有课的同学的学号、; select Sid,Sname from Student where Sid in (select Sid from SC ,Course ,Teacher where SC.Cid=Course.Cid and Teacher.Tid=Course.Tid and Teacher.Tname= 叶平 group by Sid having count(SC.Cid)=(select count(Cid) from Course,Teacher where Teacher.Tid=Course.Tid and Tname= 叶平);
10、精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 3 页，共 14 页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、; Select Sid,Sname from (select Student.Sid,Student.Sname,score ,(select score from SC SC_2 where SC_2.Sid=Student.Sid and SC_2.Cid=002) score2 from Student,SC where Student.Sid=SC.Sid and Cid=001) S_2 w
11、here score2 60); 10、查询没有学全所有课的同学的学号、; select Student.Sid,Student.Sname from Student,SC where Student.Sid=SC.Sid group by Student.Sid,Student.Sname having count(Cid) =60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分数FROM SC T,Course where t.Cid=course.Cid GROUP BY t.Cid ORDER BY 100 * SUM(CASE WHEN isnull(scor
12、e,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，OO&UML 003，数据库 004SELECT SUM(CASE WHEN Cid =001 THEN score ELSE 0 END)/SUM(CASE Cid WHEN 001 THEN 1 ELSE 0 END)AS 企业管理平均分,100 * SUM(CASE WHEN Cid = 001 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cid = 001 TH
13、EN 1 ELSE 0 END) AS 企业管理及格百分数,SUM(CASE WHEN Cid = 002 THEN score ELSE 0 END)/SUM(CASE Cid WHEN 002 THEN 1 ELSE 0 END) AS 马精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 6 页，共 14 页克思平均分,100 * SUM(CASE WHEN Cid = 002 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cid = 002 THEN 1 ELSE 0 END) AS 马克思及格
14、百分数,SUM(CASE WHEN Cid = 003 THEN score ELSE 0 END)/SUM(CASE Cid WHEN 003 THEN 1 ELSE 0 END) AS UML 平均分,100 * SUM(CASE WHEN Cid = 003 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cid = 003 THEN 1 ELSE 0 END) AS UML 及格百分数,SUM(CASE WHEN Cid = 004 THEN score ELSE 0 END)/SUM(CASE Cid WHEN 004 THEN 1 E
15、LSE 0 END) AS 数据库平均分,100 * SUM(CASE WHEN Cid = 004 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cid = 004 THEN 1 ELSE 0 END) AS 数据库及格百分数FROM SC 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.Tid) AS 教师 ID,MAX(Z.Tname) AS 教师,C.Cid AS 课程 ,MAX(C.Cname) AS 课程名称 ,AVG(Score)AS 平均成绩FROM SC AS T,Course AS C ,Teach
16、er AS Z where T.Cid=C.Cid and C.Tid=Z.Tid GROUP BY C.Cid 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,企业管理 ,马克思 ,UML,数据库 ,平均成绩SELECT DISTINCT top 3 SC.Sid As 学生学号 , Student.Sname AS 学生 , 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 7 页，共 14 页T1.scor
17、e 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.Sid = T1.Sid AND T1.Cid = 001 LEFT JOIN SC AS T2 ON SC.Sid = T2.Sid AND T2.Cid = 002 LEFT JOIN SC AS T3 ON
18、SC.Sid = T3.Sid AND T3.Cid = 003 LEFT JOIN SC AS T4 ON SC.Sid = T4.Sid AND T4.Cid = 004 WHERE student.Sid=SC.Sid 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)
19、 + ISNULL(T4.score,0) FROM sc LEFT JOIN sc AS T1 ON sc.Sid = T1.Sid AND T1.Cid = k1 LEFT JOIN sc AS T2 ON sc.Sid = T2.Sid AND T2.Cid = k2 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 8 页，共 14 页LEFT JOIN sc AS T3 ON sc.Sid = T3.Sid AND T3.Cid = k3 LEFT JOIN sc AS T4 ON sc.Sid = T4.Sid AND T4.Cid =
20、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.Cid 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 AN
21、D 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 T2.平均成绩 ) as 名次, Sid as 学生学号 ,平均成绩精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 9 页，共 14 页FROM (SELECT Sid,AVG(score) 平均成绩FROM SC GROUP BY Sid ) AS T2 ORDER BY 平均成绩 desc; 25、
22、查询各科成绩前三名的记录:(不考虑成绩并列情况 ) SELECT t1.Sid as 学生 ID,t1.Cid as 课程 ID,Score as 分数FROM SC t1 WHERE score IN (SELECT TOP 3 score FROM SC WHERE t1.Cid= Cid ORDER BY score DESC ) ORDER BY t1.Cid; 26、查询每门课程被选修的学生数select cid,count(Sid) from sc group by Cid; 27、查询出只选修了一门课程的全部学生的学号和select SC.Sid,Student.Sname,co
23、unt(Cid) AS 选课数from SC ,Student where SC.Sid=Student.Sid group by SC.Sid ,Student.Sname having count(Cid)=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” 的学生名单精选学习资料 - - - - - - - - -
24、 名师归纳总结 - - - - - - -第 10 页，共 14 页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
25、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 Cid,Avg(score) from SC group by Cid order by Avg(score),Cid DESC ; 33、查询平均成绩大于85 的所有学生的学号、和平均成绩select Sname,SC.Sid ,avg(score) from Student,SC where Student.Sid=SC.Sid group by SC.Sid,Sname having avg(score)
26、85; 34、查询课程名称为 “ 数据库 ” ，且分数低于 60 的学生和分数Select Sname,isnull(score,0) from Student,SC,Course where SC.Sid=Student.Sid and SC.Cid=Course.Cid and Course.Cname= 数据库 and score =70 AND SC.Sid=student.Sid; 37、查询不及格的课程，并按课程号从大到小排列select cid from sc where scor e 80 and Cid=003; 39、求选了课程的学生人数select count(*) fr
27、om sc; 40、查询选修 “ 叶平” 老师所授课程的学生中，成绩最高的学生及其成绩select Student.Sname,score from Student,SC,Course C,Teacher where Student.Sid=SC.Sid and SC.Cid=C.Cid and C.Tid=Teacher.Tid and Teacher.Tname= 叶平 and SC.score=(select max(score)from SC where Cid=C.Cid ); 41、查询各个课程及相应的选修人数select count(*) from sc group by Cid
28、; 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.Sid,B.score from SC A ,SC B where A.Score=B.Score and A.Cid B.Cid ; 43、查询每门功成绩最好的前两名SELECT t1.Sid as 学生 ID,t1.Cid as 课程 ID,Score as 分数FROM SC t1 WHERE score IN (SELECT TOP 2 score FROM SC WHERE t1.Cid= Cid ORDER BY score DESC ) ORDER BY t1.Cid; 精选学习资料
29、- - - - - - - - - 名师归纳总结 - - - - - - -第 12 页，共 14 页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， 假设人数相同，按课程号升序排列select Cid as 课程号,count(*) as 人数from sc group by Cid order by count(*) desc,cid 45、检索至少选修两门课程的学生学号select Sid from sc group by sid having count(*) = 2 46、查询全部学生都选修的课程
30、的课程号和课程名select Cid,Cname from Course where Cid in (select cid from sc group by cid) 47、查询没学过 “ 叶平” 老师讲授的任一门课程的学生select Sname from Student where Sid not in (select Sid from Course,Teacher,SC where Course.Tid=Teacher.Tid and SC.Cid=course.Cid 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 Sid,avg(is
31、null(score,0) from SC where Sid in (select Sid from SC where score 2)group by Sid; 49、检索 “004”课程分数小于 60，按分数降序排列的同学学号select Sid from SC where Cid=004and score 60 order by score desc; 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 13 页，共 14 页50、删除 “002”同学的 “001”课程的成绩delete from Sc where Sid=001and Cid=001; 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 14 页，共 14 页