SQL查询语句47题

select * from student
select * from score
--select * from grade
select * from course
select * from teacher

--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,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 sno,cno from score where degree in (select MAX(degree) from score)
select top 1 sno,cno from score order by degree desc
--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 in (select cno from score group by cno having COUNT(*)>=5) and cno like '3%'
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 distinct sno from score 
where sno in (select sno from score group by sno having MIN(degree)>70) 
    and sno in (select sno from score group by sno having MAX(degree)<90)
    
select sno 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,score where student.sno=score.sno
--15、查询所有学生的Sno、Cname和Degree列。
select student.sno,cname,degree from student
    join score on student.sno=score.sno
    join course 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 score
where degree in (select degree from score join student on student.sno=score.sno 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 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。//无关子查询
            --“109”号同学成绩
            --select degree from score where sno='109' and cno='3-105'
select * from student join score on student.sno=score.sno 
where cno='3-105' and degree > (select degree from score where sno='109' and cno='3-105')
--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。
--select sno from score group by sno having COUNT(*)>1
--select MAX(degree) from score group by cno
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))--相关子查询

--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
where YEAR(sbirthday)= YEAR((select sbirthday from student where sno='108'))
--23、查询“张旭“教师任课的学生成绩。
--select cno from course where course.tno=(select tno from teacher where tname='张旭')
select degree from score where cno=(select cno from course where course.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 cno from score group by cno having COUNT(*)>5
--select tno from course where cno=(select cno from score group by cno having COUNT(*)>5)
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 student.sno,sname,ssex,sbirthday,class,course.cno,degree,cname,teacher.tno,tname,tsex,prof,depart from student
join score on student.sno=score.sno 
join course on score.cno=course.cno 
join teacher on course.tno=teacher.tno
where class='95033' or class='95031' order by student.sno
--26、查询存在有85分以上成绩的课程Cno.
select distinct 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 tno from teacher where depart='计算机系'
--select cno from course where tno in (select tno from teacher where 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。//查关子查询 exists存在
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
)
--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>(select MIN(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 cno,sno,degree from score where cno='3-105' and degree>(select MAX(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.//相关子查询
select cno,sno,degree from score s1 where  cno='3-105' and sno in
(
    select sno from score where cno='3-245'
)
 and degree>
(
    select degree from score s2 where cno='3-245' and sno in
    (
        select sno from score where cno ='3-105'
    )
    and s1.sno=s2.sno
)
--31、查询所有教师和同学的name、sex和birthday.
select sname as name,ssex as sex,sbirthday as birthday from student
union 
select tname,tsex,tbirthday from teacher
--32、查询所有“女”教师和“女”同学的name、sex和birthday.
select sname as name,ssex as sex,sbirthday as birthday from student where ssex='女'
union 
select tname,tsex,tbirthday from teacher where tsex='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 where degree<(select AVG(degree) from score where cno in (select cno from score 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 cno from course where cno not in (select cno from score)
select tname,depart from teacher 
where tno in (select tno from course where cno= (select cno from course where cno not in (select cno from score)))

select tname,depart from teacher 
--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(ssex)>=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。
--(YEAR(GETDATE())-YEAR(sbirthday))
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
--41、查询“男”教师及其所上的课程。
--select tname from teacher where tsex='男'
--tsex='男' and course.tno in (select tno from teacher where tsex='男')
select tname,cname from teacher 
join course on teacher.tno=course.tno 
    where tsex='男' and course.tno in (select tno from teacher where tsex='男')
--42、查询最高分同学的Sno、Cno和Degree列。
select sno,cno,degree from score where degree in (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.//也可以用相关子查询
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 * from score where cno in (select cno from course where cname='计算机导论') and sno in (select sno from student where ssex='男')
--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 in (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 sno from score group by sno having AVG(degree)>=80
select * from student 
where sno in (select sno from score where score.sno in(select sno from score group by sno having AVG(degree)>=80))