1、 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.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、; sel
2、ect Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# and SC.C#=and exists（ Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#= 7、查询学过“叶平老师所教的所有课的同学的学号、; select S#,Sname where S# in （select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tna
3、me= group by S# having count（SC.C#）=（select count（C#） from Course,Teacher where Teacher.T#=Course.T# and Tname=）; 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 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#=） score2 from Student,S
4、C where Student.S#=SC.S# and C#=） S_2 where score2/score; 9、查询所有课程成绩小于60分的同学的学号、; where S# not in （select Student.S# from Student,SC where S.S#=SC.S# and score60）; 10、查询没有学全所有课的同学的学号、; from Student,SC where Student.S#=SC.S# group by Student.S#,Student.Sname having count（C#） =60 THEN 1 ELSE 0 END）/CO
5、UNT（*） 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 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 SELECT SUM（CASE WHEN C# = THEN score ELSE 0 END）/SUM（CASE C# WHEN THEN 1 ELSE 0 END） AS
6、企业管理平均分 ,100 * SUM（CASE WHEN C# = AND score = 60 THEN 1 ELSE 0 END）/SUM（CASE WHEN C# = THEN 1 ELSE 0 END） AS 企业管理及格百分数 ,SUM（CASE WHEN C# = THEN 1 ELSE 0 END） AS 马克思平均分 THEN 1 ELSE 0 END） AS 马克思及格百分数003 THEN 1 ELSE 0 END） AS UML平均分 THEN 1 ELSE 0 END） AS UML及格百分数 THEN 1 ELSE 0 END） AS 数据库平均分 THEN 1 EL
7、SE 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.T#） AS 教师ID,MAX（Z.Tname） AS 教师,C.C# 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 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00
8、2，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.S# As 学生学号, Student.Sname AS 学生 , 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
9、 SC.S# = T1.S# AND T1.C# = LEFT JOIN SC AS T2 ON SC.S# = T2.S# AND T2.C# = LEFT JOIN SC AS T3 ON SC.S# = T3.S# AND T3.C# = LEFT JOIN SC AS T4 ON SC.S# = T4.S# AND T4.C# = 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 DISTI
10、NCT TOP 15 WITH TIES 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,
11、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 TH
12、EN 1 ELSE 0 END） AS 70 - 60 ,SUM（CASE WHEN score 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 ） 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 WHERE t1.C#= C# ORDER BY score DESC ）
13、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 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 h
14、aving 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（c
15、har （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、和平均成绩 select Sname,SC.S# ,avg（score） where Student.S#=SC.S# group
16、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#=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#= 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= and SC.score=（select max（score）from SC where C#=C.C#
