Mysql多表练习题记录

xiaoxiao2021-03-01  2

create table student ( sno varchar(20) not null primary key, sname varchar(20) not null, ssex varchar(20) not null, sbirthday datetime, class varchar(20) ); insert into student values('108','曾华','男','1977-09-01','95033'); insert into student values('105','匡明','男','1975-10-02','95031'); insert into student values('107','王丽','女','1976-01-23','95033'); insert into student values('101','李军','男','1976-02-20','95033'); insert into student values('109','王芳','女','1975-02-10','95031'); insert into student values('103','陆君','男','1974-06-03','95031'); create table teacher ( tno varchar(20) not null primary key, tname varchar(20) not null, tsex varchar(20) not null, tbirthday datetime, prof varchar(20), depart varchar(20) not null ); insert into teacher values('804','李诚','男','1958-12-02','副教授','计算机系'); insert into teacher values('856','张旭','男','1969-03-12','讲师','电子工程系'); insert into teacher values('825','王萍','女','1972-05-05','助教','计算机系'); insert into teacher values('831','刘冰','女','1977-08-14','助教','电子工程系'); create table course ( cno varchar(20) not null primary key, cname varchar(20) not null, tno varchar(20) not null, foreign key(tno) references teacher(tno) ); insert into course values('3-105','计算机导论','825'); insert into course values('3-245','操作系统','804'); insert into course values('6-166','数字电路','856'); insert into course values('9-888','高等数学','831'); create table score ( sno varchar(20) not null primary key, foreign key(sno) references student(sno), cno varchar(20) not null, foreign key(cno) references course(cno), degree decimal ); insert into score values('103','3-245','86'); insert into score values('105','3-245','75'); insert into score values('109','3-245','68'); insert into score values('101','3-105','92'); insert into score values('107','3-105','88'); insert into score values('108','3-105','76'); insert into score values('109','3-105','64'); insert into score values('104','3-105','91'); insert into score values('100','3-105','78'); insert into score values('102','6-166','85'); insert into score values('104','6-166','79'); insert into score values('109','6-166','81'); select * from score 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 distinct Depart from teacher 3、 查询Student表的所有记录。 select * from student 4、 查询Score表中成绩在6080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858688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(*) from student where class='95031' 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 sno,cno from score where degree=(select max(degree) from score) --方式二 SELECT sno,cno from score ORDER BY degree desc limit 1 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 avg(degree) from score where cno like '3%' and cno in( select cno from score group by cno having count(*)>=5) --方式二: select avg(degree) from score where cno like '3%' group by cno having count(*)>=5 13、     查询分数大于70,小于90的Sno列。 select sno from score where degree>70 and degree<90 14、     查询所有学生的Sname、Cno和Degree列。 select sname,cno,degree from score,student where score.sno=student.sno 15、     查询所有学生的Sno、Cname和Degree列。 select sno,cname,degree from score s,course c where s.cno=c.cno 16、     查询所有学生的Sname、Cname和Degree列。 select sname,degree from student s,course c,score sc where s.sno=sc.sno and c.cno=sc.cno --使用join....on方式 select sname,cname,degree from student s join score sc on s.sno=sc.sno join course c on sc.cno=c.cno 17、     查询“95033”班学生的平均分。 select avg(degree) as avgdegree from score where sno in(select sno from student where class='95033') 18、 假设使用如下命令建立了一个grade表: drop table grade create table grade(low int(3),upp int(3),rank char(1)) insert into grade values(90,100,'A'); insert into grade values(80,89,'B'); insert into grade values(70,79,'C'); insert into grade values(60,69,'D'); insert into grade values(0,59,'E'); select * from grade SELECT * from score 现查询所有同学的Sno、Cno和rank列。 select score.sno,score.cno,grade.rank from score,grade where score.degree BETWEEN grade.low and grade.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 where cno='3-105' and degree>( select max(degree) from score where sno='109' and cno='3-105' ) 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108101的同学同年出生的所有学生的Sno、Sname和Sbirthday列。 select sno,sname,sbirthday from student where year(sbirthday)=( select year(sbirthday) from student where sno='108' ) 23、查询“张旭“教师任课的学生成绩。 select sno,degree from score s,course c where s.cno=c.cno and c.tno=( select tno from teacher where tname='张旭' ) --方式二 select degree from score where cno in( select cno from course where tno=( select tno from teacher 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 t,course c where t.tno=c.tno and c.cno=( select cno from score GROUP BY cno HAVING count(*)>5 ) --方式二 select tname from teacher where tno=( select tno from course where cno=( select cno from score GROUP BY 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') 26、  查询存在有85分以上成绩的课程Cno. select cno from score where degree>85 27、查询出“计算机系“教师所教课程的成绩表。 select * from course 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 tname,prof from teacher where depart='计算机系' and prof not in( select prof from teacher where depart='电子工程系' ) 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。 any:代表括号中任意一个成绩就可以 select cno,sno,degree from score where cno='3-105' and degree>any( select degree from score where cno='3-245' )ORDER BY degree desc 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. all:代表括号中的所有成绩 select cno,sno,degree from score where cno='3-105' and degree>all( select degree from score where cno='3-245' )ORDER BY degree desc 31、 查询所有教师和同学的name、sex和birthday. select tname,tsex,tbirthday 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,tsex,tbirthday 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 a where degree<(select avg(degree) from score b where b.cno=a.cno) 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 ) 35 、 查询所有未讲课的教师的Tname和Depart. select tname,depart from teacher where tno not in( select tno from course where cno in( select cno from score ) ) 36、查询至少有2名男生的班号。 select class from student where ssex='男' GROUP BY class HAVING count(*)>1 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(NOW())-year(sbirthday) from student 39、查询Student表中最大和最小的Sbirthday日期值。 select max(sbirthday),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 * from student ORDER BY class desc,sbirthday desc 41、查询“男”教师及其所上的课程。 select tname,cname from course c,teacher t where c.tno=t.tno and t.tsex='男' 42、查询最高分同学的Sno、Cno和Degree列。 select sno,cno,degree from score where degree=( select max(degree) from score ) --排序写法 select sno,cno,degree from score ORDER BY degree desc limit 1 43、查询和“李军”同性别的所有同学的Sname. select sname from student where ssex=( select ssex from student where sname='李军' ) 44、查询和“李军”同性别并同班的同学Sname. select sname from student where ssex=( select ssex from student where sname='李军' ) and class=( select class from student where sname='李军' ) 45、查询所有选修“计算机导论”课程的“男”同学的成绩表。 select sno,cno,degree from score where cno=( select cno from course where cname='计算机导论' )and sno in(select sno from student where ssex='男')
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