create database mydbgouse mydbcreate table student(    --学号    sno varchar(3) not null primary key,    --姓名    sname varchar(4) not null,    --性别    ssex varchar(2) not null,    --出生年月    sbirthday datetime,    --所在班级    class varchar(5))create table teacher(    --教工编号    tno varchar(3) not null primary key,    --教工姓名    tname varchar(4) not null,    --教工性别    tsex varchar(2) not null,    --教工出生日期    tbirthday datetime,    --职称    prof varchar(6),    --所在部门    depart varchar(10))create table course(    --课程号    cno varchar(5) not null primary key,    --课程名称    cname varchar(10) not null,    --教工编号    tno varchar(3) references teacher(tno))create table score(    --学号    sno varchar(3) not null references student(sno),    --课程号    cno varchar(5) not null references course(cno),    --成绩    degree decimal(4,1))insert into studentvalues(‘108‘,‘曾华‘,‘男‘,‘1977-09-01‘,‘95033‘)insert into studentvalues(‘105‘,‘匡明‘,‘男‘,‘1975-10-02‘,‘95031‘)insert into studentvalues(‘107‘,‘王丽‘,‘女‘,‘1976-01-23‘,‘95033‘)insert into studentvalues(‘101‘,‘李军‘,‘男‘,‘1976-02-20‘,‘95033‘)insert into studentvalues(‘109‘,‘王芳‘,‘女‘,‘1975-02-10‘,‘95031‘)insert into studentvalues(‘103‘,‘陆君‘,‘男‘,‘1974-06-03‘,‘95031‘)insert into teachervalues(‘804‘,‘李诚‘,‘男‘,‘1958-12-02‘,‘副教授‘,‘计算机系‘)insert into teachervalues(‘856‘,‘张旭‘,‘男‘,‘1969-03-12‘,‘讲师‘,‘电子工程系‘)insert into teachervalues(‘825‘,‘王萍‘,‘女‘,‘1972-05-05‘,‘助教‘,‘计算机系‘)insert into teachervalues(‘831‘,‘刘冰‘,‘女‘,‘1958-08-14‘,‘助教‘,‘电子工程系‘)insert into coursevalues(‘3-105‘,‘计算机导论‘,‘825‘)insert into coursevalues(‘3-245‘,‘操作系统‘,‘804‘)insert into coursevalues(‘6-166‘,‘数字电路‘,‘856‘)insert into coursevalues(‘9-888‘,‘高等数学‘,‘831‘)insert into scorevalues(‘103‘,‘3-245‘,‘86‘)insert into scorevalues(‘105‘,‘3-245‘,‘75‘)insert into scorevalues(‘109‘,‘3-245‘,‘68‘)insert into scorevalues(‘103‘,‘3-105‘,‘92‘)insert into scorevalues(‘105‘,‘3-105‘,‘88‘)insert into scorevalues(‘109‘,‘3-105‘,‘76‘)insert into scorevalues(‘101‘,‘3-105‘,‘64‘)insert into scorevalues(‘107‘,‘3-105‘,‘91‘)insert into scorevalues(‘108‘,‘3-105‘,‘78‘)insert into scorevalues(‘101‘,‘6-166‘,‘85‘)insert into scorevalues(‘107‘,‘6-166‘,‘79‘)insert into scorevalues(‘108‘,‘6-166‘,‘81‘)select * from studentselect * from teacherselect * from courseselect * 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。--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 80select * from score where degree  >=60 and degree<=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(*) from student where class=‘95031‘--10、查询Score表中的最高分的学生学号和课程号。select top 1 sno,cno from score order by degree descselect sno ,cno from score where degree  = (    select MAX(degree) from score)--11、查询‘3-105’号课程的平均分。select AVG(degree) from score where cno = ‘3-105‘--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)select AVG(degree) from score where cno like ‘3%‘ group by cno having COUNT(*) >=5  --13、查询最低分大于70，最高分小于90的Sno列。select sno,MAX(degree),MIN(degree) from score group by sno having MAX(degree) < 90 and MIN(degree)>70--14、查询所有学生的Sname、Cno和Degree列。select sname,cno,degree from student     join score on student.sno = score.sno        --15、查询所有学生的Sno、Cname和Degree列。select sno,cname,DEGREE from course    join score on score.cno = course.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 score.cno = course.cno--17、查询“95033”班所选课程的平均分。select AVG(degree) from student    join score on student.sno = score.snowhere class = ‘95033‘select AVG(degree) 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：create table grade(low  int,upp  int,rank  varchar(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‘)--现查询所有同学的Sno、Cno和rank列。select * from scoreselect * from gradeselect sno,cno,rank from score    join grade on 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。//无关子查询select * from  student where sno in(    select sno from score where cno = ‘3-105‘ and degree >     (        select degree from score where cno = ‘3-105‘ and sno = ‘109‘    ))--20、查询score中选学多门课程的同学中分数为非最高分成绩的记录。 //相关子查询select * from score a where sno in(    select sno from score group by sno having COUNT(*) >1)and degree not in(    select MAX(degree) from score b where a.cno = b.cno  group by cno )--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 * from student where year(sbirthday) =(    select year(sbirthday) from student where sno = ‘109‘)--23、查询“张旭“教师任课的学生成绩。select * from teacher     join course on teacher.tno = course.tno    join score on course.cno = score.cnowhere tname=‘张旭‘select * from score where cno  =(    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 where tno in(    select tno from course where cno in     (        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‘)select * from student where class=‘95033‘unionselect * from student where class=‘95031‘--26、查询存在有85分以上成绩的课程Cno.select distinct cno from score where degree > 85select cno from score group by cno having MAX(degree) >85--27、查询出“计算机系“教师所教课程的成绩表。select * from teacherselect * from courseselect * from scoreselect score.sno,score.cno,score.degree from teacher     join course on teacher.tno = course.tno    join score on course.cno = score.cnowhere depart= ‘计算机系‘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。 //相关子查询select * from teacher t1 where depart=‘计算机系‘ and  not exists(    select * from teacher t2 where depart = ‘电子工程系‘ and t1.prof = t2.prof)unionselect * from teacher t1 where depart=‘电子工程系‘ and  not exists(    select * from teacher t2 where depart = ‘计算机系‘ and t1.prof = t2.prof)--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。--查询3-105大于3-245最高份的所有的成绩记录select * from score where cno = ‘3-105‘ and degree >(    select MAX(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.//相关子查询select * from score s1 where sno in(    select sno from score where cno in (‘3-105‘,‘3-245‘) group by sno having COUNT(*) > 1) and cno = ‘3-105‘ and degree >(    select degree from score s2 where sno in    (        select sno from score where cno in (‘3-105‘,‘3-245‘) group by sno having COUNT(*) > 1    ) and cno = ‘3-245‘ and s1.sno = s2.sno)--31、查询所有教师和同学的name、sex和birthday.select tname,tsex,tbirthday from teacherunionselect 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‘unionselect 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。 //相关子查询--求每门科的平均分--求成绩低于平均分的成绩select * from score s1 where degree <(    select AVG(degree) from score s2 where s1.cno = s2.cno group by cno)--34、查询所有任课教师的Tname和Depart.select tname,depart from teacher--35  查询所有未讲课的教师的Tname和Depart. select tname,depart from teacher    left join course on teacher.tno = course.tno    left join score on course.cno = score.cnowhere score.sno is nullselect tname,depart from teacher where tno in(    select tno from course where cno not in    (        select distinct 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(GETDATE())-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 asc--41、查询“男”教师及其所上的课程。select course.* from teacher     join course on teacher.tno = course.tnowhere tsex=‘男‘select * from course where tno in(    select tno from teacher where tsex=‘男‘)--42、查询最高分同学的Sno、Cno和Degree列。select * from score where degree =(    select MAX(degree) from score)--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 * from student where ssex=(    select ssex from student where sname=‘李军‘)and class=(    select class from student where sname=‘李军‘)select * from student s1 where ssex=(    select ssex from student s2 where sname=‘李军‘ and s1.class=s2.class)--45、查询所有选修“计算机导论”课程的“男”同学的成绩表。select student.* from score     join course on score.cno = course.cno    join student on score.sno = student.snowhere cname = ‘计算机导论‘ and ssex=‘男‘select * from student where ssex=‘男‘ and sno in(    select sno from score where cno in    (        select cno from course where cname=‘计算机导论‘    ))--46、查询score表中分数最高的学生的信息。//多层嵌套select * from student where sno in (    select sno from score where degree =    (        select MAX(DEGREE) from score    ))--47、查询score表中的平均分在80分以上的学生信息。//无关查询select * from student where sno in(    select sno from score group by sno having AVG(degree)>80)