数据库 基础学习6— 查询 练习题
2015-07-19 22:48
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--1、 查询Student表中的所有记录的Sname、Ssex和Class列。 select Sname,Ssex,Class from Student --2、 查询教师所有的单位即不重复的Depart列。 --select COUNT(*) from Teacher group by Depart select distinct Depart from Teacher --3、 查询Student表的所有记录。 select *from Student select Sno,Sname,Ssex,Sbirthday,Class from Student --4、 查询Score表中成绩在60到80之间的所有记录。 select * from Score where Degree between 60 and 80 --5、 查询Score表中成绩为85,86或88的记录。 select * from Score where Degree in(85,86,88) --6、 查询Student表中“95031”班或性别为“女”的同学记录。 select * from Student where Class='95031' or Ssex='女' --7、 以Class降序查询Student表的所有记录。 select * from Student order by Class desc --8、 以Cno升序、Degree降序查询Score表的所有记录。 select * from Score order by Cno asc, Degree desc --9、 查询“95031”班的学生人数。 select count(class) from Student group by Class having Class='95031' select COUNT(*) from student where class='95031'--优 --10、 查询Score表中的最高分的学生学号和课程号。(子查询或者排序) select * from Score where Degree=(select MAX(Degree) from Score) select top 1 *from Score order by Degree desc --11、 查询每门课的平均成绩。 select Cno,AVG(Degree) from score group by Cno-- --12、查询Score表中至少有5名学生选修的并以3开头的课程的平均分数 select Cno,AVG(Degree) from Score group by cno having (COUNT(*)>5) and (cno like '3%') --13、查询分数大于70,小于90的Sno列。 select Sno from Score where Degree>70 and Degree<90 select Sno from Score where Degree between 70 and 90--包含临界值 --14、查询所有学生的Sname、Cno和Degree列。 select Sname,Cno,Degree,Class from Student,Score where Student.Sno=Score.Sno --15、查询所有学生的Sno、Cname和Degree列。 select Sno,Cname,Degree from Course,Score where Course.Cno=Score.Cno --16、查询所有学生的Sname、Cname和Degree列。 select Sname,Cname,Degree from Student join score on Student.Sno=Score.Sno join Course on Course.Cno=Score.Cno --17、 查询“95033”班学生的平均分。 select cno,avg(Degree) from Student,Score where (Student.Sno=Score.Sno) and (Student.Class='95033') group by Score.Cno select avg(Degree) from Student,Score where (Student.Sno=Score.Sno) and (Student.Class='95033') --18、 假设使用如下命令建立了一个grade表:现查询所有同学的Sno、Cno和rank列。 (select Sno,Cno,rank from Score,grade where (Score.Degree between 90 and 100)and grade.rank='A') union (select Sno,Cno,rank from Score,grade where (Score.Degree between 80 and 89)and grade.rank='B') union (select Sno,Cno,rank from Score,grade where (Score.Degree between 70 and 79)and grade.rank='C') union (select Sno,Cno,rank from Score,grade where (Score.Degree between 60 and 69)and grade.rank='D') union (select Sno,Cno,rank from Score,grade where (Score.Degree between 0 and 59)and grade.rank='E') select Sno,Cno,rank from Score,grade where Degree between low and upp --19、 查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。 select * from Score select * from Score where Cno='3-105' and Degree>(select degree from Score where Sno='109'and Cno='3-105') --select * from Score where (degree>(select Degree from Score where Sno=109)) in (Cno='3-105') --20、查询score中选学多门课程的同学,这些同学中分数为非最高分成绩的记录。---- select * from score where degree not in (select MAX(Degree) from Score where Sno in (select Sno from Score group by sno having COUNT(*)>1 )) and (Sno in (select sno from Score group by sno having COUNT(*)>1)) --21、 查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。 select * from Score where Degree>(select degree from Score where Sno='109'and Cno='3-105') --22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。 select Sno,Sname,Sbirthday from Student s1 where (YEAR(s1.Sbirthday) in (select YEAR(s2.Sbirthday) from Student s2 where Sno='108' ))and(Sno!='108') --23、查询“张旭“教师任课的学生成绩。 select *from Score s3 where s3.Cno=(select Cno from Course s2 where s2.Tno=(select Tno from Teacher s1 where Tname='张旭')) --24、查询选修某课程的同学人数多于5人的教师姓名。 select Tname from Teacher s1 where Tno in (select Tno from Course s2 where cno in (select Cno from Score group by Cno having COUNT(*)>5)) --select Tname from (Teacher join Course on Teacher.Tno=Course.Tno join Score on Course.Cno=Score.Cno) group by score.Cno having count(*)>5 --25、查询95033班和95031班全体学生的记录。 select *from Student where Class in (95033,95031) select * from Teacher join Course on Course.Tno=Teacher.Tno join Score on Course.Cno=Score.Cno join (select *from Student where Class in (95033,95031)) s1 on Score.Sno=s1.Sno --26、 查询存在有85分以上成绩的课程Cno. select * from Score select cno from Score group by Cno having MAX(Degree)>85--分组 select distinct Cno from Score where Degree>85--distinct消除重复行 --27、查询出“计算机系“教师所教课程的成绩表。 select * from Score where Cno in(select Cno from Course where Tno in (select Tno from Teacher where Depart='计算机系')) --28、查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。 select * from Teacher select Tname,Prof from Teacher s1 where Depart='计算机系' and not exists(select Prof from Teacher s2 where Depart='电子工程系' and s1.Prof=s2.Prof)--加上and 条件目的就是让前面的一记录一条一条的判定,而不是等着前面的条件执行完了,再跟后面的判断! union select Tname,Prof from Teacher s1 where Depart='电子工程系' and not exists(select Prof from Teacher s2 where Depart='计算机系' and s1.Prof=s2.Prof)--exists 意思 就是()里只要返回数据就是真!不返回数据 空表就false! --29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。 select Cno,Sno,Degree from Score where Cno='3-105' and Degree >any (select Degree from Score where Cno='3-245') select Cno,Sno,Degree from Score where Cno='3-105' and Degree >(select min(Degree) from Score where Cno='3-245') --30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree. select * from Score select Cno,Sno,Degree from Score where Cno='3-105' and Degree >(select max(Degree) from Score where Cno='3-245') select Cno,Sno,Degree from Score where Cno='3-105' and Degree >all (select Degree from Score where Cno='3-245') --31、 查询所有教师和同学的name、sex和birthday. select Tname 'name',Tsex 'sex',Tbirthday 'birthday' from Teacher union select Sname,Ssex,Sbirthday from Student --32、查询所有“女”教师和“女”同学的name、sex和birthday. select Tname 'name',Tsex 'sex',Tbirthday 'birthday' from Teacher where Tsex='女' union select Sname,Ssex,Sbirthday from Student where Ssex='女' --33、 查询成绩比该课程平均成绩低的同学的成绩表。 select *from Score s1 where Degree <( select AVG(Degree) from Score s2 group by Cno having s1.Cno=s2.Cno )---相关子查询 --34、 查询所有任课教师的Tname和Depart. select Tname,Depart from Teacher where Tno in( select Tno from Course where Cno in ( select Cno from Score group by Cno)) --35 、 查询所有未讲课的教师的Tname和Depart. select Tname from Teacher where Tno in( select Tno from Course where Cno not in ( select Cno from Score group by Cno)) --36、查询至少有2名男生的班号。 select s1.Class from (select Class from Student where Ssex='男') s1 group by s1.Class having COUNT(*)>=2 --37、查询Student表中不姓“王”的同学记录。 select *from Student where Sname not like '王%' --38、查询Student表中每个学生的姓名和年龄。 select Sname,(YEAR(GETDATE())-YEAR(Sbirthday)) '年龄' from student --39、查询Student表中最大和最小的Sbirthday日期值。 select MAX(Sbirthday) from student union select min(Sbirthday) from student --40、以班号和年龄从大到小的顺序查询Student表中的全部记录。 select Sno,sname,ssex,class,(YEAR(GETDATE())-YEAR(Sbirthday)) '年龄' from student order by Class desc ,年龄 desc --41、查询“男”教师及其所上的课程。 select * from Course,Teacher where Teacher.Tno=Course.Tno and Teacher.Tsex='男' --42、查询最高分同学的Sno、Cno和Degree列。 select *from Score select Sno,Cno,Degree from Score where Degree=(select MAX(Degree) from Score) --查询总成绩最高分的 select Sno,Cno,Degree from Score where sno in (select top 1 Sno from Score group by Sno order by SUM(Degree) desc) --43、查询和“李军”同性别的所有同学的Sname. select * from Student select Sname from Student where Ssex =(select Ssex from Student where Sname='李军') and (Sname!='李军') --44、查询和“李军”同性别并同班的同学Sname. select Sname from Student where Class=(select Class from Student where Sname='李军') and Ssex =(select Ssex from Student where Sname='李军')and(Sname!='李军') --相关子查询--关键是分析出哪个是关键点 select * from Student select Class,sname from student s1 where ssex=(select class,sname,ssex from student s2 where sname='李军' and s2.class= s1.class) --45、查询所有选修“计算机导论”课程的“男”同学的成绩表。 select Degree from Score where cno=(select Cno from course s1 where Cname='计算机导论') and( Sno in (select Sno from Student where Ssex='男'))
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