1、SQL 基础学生成绩表项目让你从入门到精通-50 个 sql语句Student(Sno,Sname,Sage,Ssex) 学生表 SCourse(Cno,Cname,Tno) 课程表 CSC(Sno,Cno,score) 成绩表Teacher(Tno,Tname) 教师表 T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.Sno from (select sno,score from SC where Cno=001) a ,(select sno,score from SC where Cno=002) bwhere a.score b.scoreand
2、 a.sno = b.sno;/2 张表比较，1 张是 001 课程表，1 张是 002 课程表2、查询平均成绩大于 60 分的同学的学号和平均成绩；select Sno , avg(score)from scgroup by Snohaving avg(score) 60;Student(Sno,Sname,Sage,Ssex) 学生表 SCourse(Cno,Cname,Tno) 课程表 CSC(Sno,Cno,score) 成绩表 Teacher(Tno,Tname) 教师表 T3、查询所有同学的学号、姓名、选课数、总成绩；select S.Sno , S.Sname , count(S
3、C.Cno) , sum(score)from S left Outer join SC on S.Sno = SC.Snogroup by S.Sno , Sname4、查询姓“李” 的老师的个数；select count(distinct(Tname)from Twhere Tname like 李%;5、查询没学过“ 叶平”老师课的同学的学号、姓名； 1找出叶平老师的课程号 select S.Sno , S.Sname from Swhere Sno not in (select distinct( SC.Sno) from SC , C , Twhere SC.Cno = C.Cnoa
4、nd T.Tno = C.Tnoand T.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 S.Sno , S.Sname from S , SCwhere S.Sno=SC.Sno and SC.Cno=001 andexists( Select * from SC as SC_2 where SC_2.Sno=SC.Sno and SC_2.Cno=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 Sno,Sname from Studentwhere Sno in(select Sno fro
5、m SC ,Course ,Teacherwhere SC.Cno=Course.Cno and Teacher.Tno=Course.Tno and Teacher.Tname=叶平group by Snohaving count(SC.Cno) =);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 Sno,Sname from (select Student.Sno,Student.Sname,score ,(select score from SC SC_2 where SC_2.Sno=Student.Sno and SC_2.Cno
6、=002) score2from Student,SC where Student.Sno=SC.Sno and Cno=001) S_2 where score2score;9、查询所有课程成绩小于 60 分的同学的学号、姓名；select Sno,Snamefrom Studentwhere Sno not in (select Student.Sno from Student,SC where S.Sno=SC.Sno and score60);10、查询没有学全所有课的同学的学号、姓名；select Student.Sno,Student.Snamefrom Student,SCwhe
7、re Student.Sno=SC.Sno group by Student.Sno,Student.Sname having count(Cno)(select count(Cno) 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 Sno,Sname from Student,SC where Student.Sno=SC.Sno and Cno in select Cno from SC where Sno=1001;12、查询至少学过学号为 “1001”同学所有一门课的其他同学学号和姓名；select distinct SC
8、.Sno,Snamefrom Student,SCwhere Student.Sno=SC.Sno and Cno in (select Cno from SC where Sno=001);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_2where SC_2.Cno=SC.Cno ) from Course,Teacher where Course.Cno=SC.Cno and Course.Tno=Teacher.Tno and Teacher.Tname=
9、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；select Sno from SC where Cno in (select Cno from SC where Sno=1002)group by Sno having count(*)=(select count(*) from SC where Sno=1002);15、删除学习“叶平 ”老师课的 SC 表记录；Delect SCfrom course ,Teacherwhere Course.Cno=SC.Cno and Course.Tno= Teacher.Tno and Tname=叶平;16、向
10、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 Sno,002,(Select avg(score)from SC where Cno=002) from Student where Sno not in (Select Sno from SC where Cno=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SELECT Sno as 学生 ID,(SELECT
11、 score FROM SC WHERE SC.Sno=t.Sno AND Cno=004) AS 数据库,(SELECT score FROM SC WHERE SC.Sno=t.Sno AND Cno=001) AS 企业管理,(SELECT score FROM SC WHERE SC.Sno=t.Sno AND Cno=006) AS 英语,COUNT(*) AS 有效课程数 , AVG(t.score) AS 平均成绩FROM SC AS tGROUP BY SnoORDER BY avg(t.score)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SE
12、LECT L.Cno As 课程 ID,L.score AS 最高分 ,R.score AS 最低分FROM SC L ,SC AS RWHERE L.Cno = R.Cno andL.score = (SELECT MAX(IL.score)FROM SC AS IL,Student AS IMWHERE L.Cno = IL.Cno and IM.Sno=IL.SnoGROUP BY IL.Cno)ANDR.Score = (SELECT MIN(IR.score)FROM SC AS IRWHERE R.Cno = IR.CnoGROUP BY IR.Cno);19、按各科平均成绩从低到
13、高和及格率的百分数从高到低顺序SELECT t.Cno 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,Coursewhere t.Cno=course.CnoGROUP BY t.CnoORDER BY 100 * SUM(CASE WHEN isnull(score,0)=60 THEN 1 ELSE 0 END)/COUNT(*) DESC20、查询
14、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） ，OOUML （003） ，数据库（004 ）SELECT SUM(CASE WHEN Cno =001 THEN score ELSE 0 END)/SUM(CASE Cno WHEN 001 THEN 1 ELSE 0 END) AS 企业管理平均分,100 * SUM(CASE WHEN Cno = 001 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cno = 001 THEN 1 ELSE 0 END) AS 企业管理及格百分数,SUM(
15、CASE WHEN Cno = 002 THEN score ELSE 0 END)/SUM(CASE Cno WHEN 002 THEN 1 ELSE 0 END) AS 马克思平均分,100 * SUM(CASE WHEN Cno = 002 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cno = 002 THEN 1 ELSE 0 END) AS 马克思及格百分数,SUM(CASE WHEN Cno = 003 THEN score ELSE 0 END)/SUM(CASE Cno WHEN 003 THEN 1 ELSE 0 END)
16、 AS UML 平均分,100 * SUM(CASE WHEN Cno = 003 AND score = 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN Cno = 003 THEN 1 ELSE 0 END) AS UML 及格百分数,SUM(CASE WHEN Cno = 004 THEN score ELSE 0 END)/SUM(CASE Cno WHEN 004 THEN 1 ELSE 0 END) AS 数据库平均分,100 * SUM(CASE WHEN Cno = 004 AND score = 60 THEN 1 ELSE 0 END)/SUM(CA
17、SE WHEN Cno = 004 THEN 1 ELSE 0 END) AS 数据库及格百分数FROM SC21、查询不同老师所教不同课程平均分从高到低显示SELECT max(Z.Tno) AS 教师 ID,MAX(Z.Tname) AS 教师姓名,C.Cno 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 ,Teacher AS Zwhere T.Cno=C.Cno and C.Tno=Z.TnoGROUP BY C.CnoORDER BY AVG(Score) DESC22、查询如下课程成绩第
18、 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 3SC.Sno 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
19、总分FROM Student,SC LEFT JOIN SC AS T1ON SC.Sno = T1.Sno AND T1.Cno = 001LEFT JOIN SC AS T2ON SC.Sno = T2.Sno AND T2.Cno = 002LEFT JOIN SC AS T3ON SC.Sno = T3.Sno AND T3.Cno = 003LEFT JOIN SC AS T4ON SC.Sno = T4.Sno AND T4.Cno = 004WHERE student.Sno=SC.Sno andISNULL(T1.score,0) + ISNULL(T2.score,0) +
20、ISNULL(T3.score,0) + ISNULL(T4.score,0)NOT IN(SELECTDISTINCTTOP 15 WITH TIESISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)FROM scLEFT JOIN sc AS T1ON sc.Sno = T1.Sno AND T1.Cno = k1LEFT JOIN sc AS T2ON sc.Sno = T2.Sno AND T2.Cno = k2LEFT JOIN sc AS T3ON sc.Sno = T3
21、.Sno AND T3.Cno = k3LEFT JOIN sc AS T4ON sc.Sno = T4.Sno AND T4.Cno = k4ORDER 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,100-85,85-70,70-60,60SELECT SC.Cno as 课程 ID, Cname as 课程名称,SUM(CASE WHEN score BETWEEN 85 AND 100 TH
22、EN 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,Coursewhere SC.Cno=Course.CnoGROUP BY SC.Cno,Cname;24、查询学生平均成绩及其名次SELECT 1+(SE
23、LECT COUNT( distinct 平均成绩)FROM (SELECT Sno,AVG(score) AS 平均成绩FROM SCGROUP BY Sno) AS T1WHERE 平均成绩 T2.平均成绩) as 名次,Sno as 学生学号,平均成绩FROM (SELECT Sno,AVG(score) 平均成绩FROM SCGROUP BY Sno) AS T2ORDER 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.Sno as 学生 ID,t1.Cno as 课程 ID,Score as 分数FROM SC t1WHERE
24、score IN (SELECT TOP 3 scoreFROM SCWHERE t1.Cno= CnoORDER BY score DESC)ORDER BY t1.Cno;26、查询每门课程被选修的学生数select cno,count(Sno) from sc group by Cno;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.Sno,Student.Sname,count(Cno) AS 选课数from SC ,Studentwhere SC.Sno=Student.Sno group by SC.Sno ,Student.Sname having coun
25、t(Cno)=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 coun
26、t(*)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 agefrom studentwhere 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 Cno,Avg(score) from SC group by Cno order by Avg(score),Cno DESC ;33、查询平均成绩大
27、于 85 的所有学生的学号、姓名和平均成绩select Sname,SC.Sno ,avg(score)from Student,SCwhere Student.Sno=SC.Sno group by SC.Sno,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,Coursewhere SC.Sno=Student.Sno and SC.Cno=Course.Cno and Course.Cname=数据库and score60;35
28、、查询所有学生的选课情况；SELECT SC.Sno,SC.Cno,Sname,CnameFROM SC,Student,Coursewhere SC.Sno=Student.Sno and SC.Cno=Course.Cno ;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.Sno,student.Sname,SC.Cno,SC.scoreFROM student,ScWHERE SC.score=70 AND SC.Sno=student.Sno;37、查询不及格的课程，并按课程号从大到小排列select cno from
29、sc where scor e60 order by Cno ;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.Sno,Student.Sname from SC,Student where SC.Sno=Student.Sno and Score80 and Cno=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,scorefrom Student,SC,Course C,Teacherwhere
30、Student.Sno=SC.Sno and SC.Cno=C.Cno and C.Tno=Teacher.Tno and Teacher.Tname=叶平 and SC.score=(select max(score)from SC where Cno=C.Cno );41、查询各个课程及相应的选修人数select count(*) from sc group by Cno;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.Sno,B.score from SC A ,SC B where A.Score=B.Score and A.CnoB.Cno
31、 ;43、查询每门功成绩最好的前两名SELECT t1.Sno as 学生 ID,t1.Cno as 课程 ID,Score as 分数FROM SC t1WHERE score IN (SELECT TOP 2 scoreFROM SCWHERE t1.Cno= CnoORDER BY score DESC)ORDER BY t1.Cno;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 Cno as 课程号 ,count(*) as 人数from scgrou
32、p by Cnoorder by count(*) desc,cno45、检索至少选修两门课程的学生学号select Snofrom scgroup by snohaving count(*) = 246、查询全部学生都选修的课程的课程号和课程名select Cno,Cnamefrom Coursewhere Cno in (select cno from sc group by cno)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 Sno not in (select Sno from Course,Teacher,S
33、C where Course.Tno=Teacher.Tno and SC.Cno=course.Cno 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 Sno,avg(isnull(score,0) from SC where Sno in (select Sno from SC where score60 group by Sno having count(*)2)group by Sno;49、检索“004 ”课程分数小于 60，按分数降序排列的同学学号select Sno from SC where Cno=004and score 60 order by score desc;50、删除“002 ”同学的“001”课程的成绩delete from Sc where Sno=001and Cno=001;
