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面试sql

news 2025/9/9 21:19:14

创建表

create table Student
(  Sno varchar(20) primary key,Sname varchar(20) UNIQUE,Ssex varchar(2),Sbirthday date,class varchar(20)   
)create table Course
(  Cno varchar(20) primary key,Cname varchar(20) UNIQUE,Tno varchar(20)   
)create table Score
(  Sno varchar(20),Cno varchar(20),Degree smallint,primary key(Sno,Cno),FOREIGN KEY (Cno) references Course(Cno),FOREIGN KEY (Sno) references Student(Sno)
)create table Teacher
(  Tno varchar(20) primary key,Tname varchar(20) UNIQUE,Tsex varchar(20),Tbirthday date,Prof varchar(20),Depart varchar(20)  
)

INSERT INTO Student (Sno,Sname,Ssex,Sbirthday,class)VALUES('108','曾华','男','1997/09/01','95033'),('105','匡明','男','1995/10/02','95031'),('107','王丽','女','1996/01/23','95033'),('101','李军','男','1996/02/20','95033'),('109','王芳','女','1995/02/10','95031'),('103','陆君','男','1994/06/03','95031');        INSERT INTO Course(Cno,Cname,Tno)VALUES('3-105','计算机导论','825'),('3-245','操作系统','804'),('6-166','数字电路','856'),('9-888','高等数学','831') ;INSERT INTO Score(Sno,Cno,Degree)VALUES('103','3-245',86),('105','3-245',75),('109','3-245',68),('103','3-105',92),('105','3-105',88),('109','3-105',76),('101','3-105',64),('107','3-105',91),('108','3-105',78),('101','6-166',85),('107','6-166',79),('108','6-166',81);INSERT INTO Teacher (Tno,Tname,Tsex,Tbirthday,prof,Depart)VALUES('804','李城','男','1980-12-02','副教授','计算机系'),('856','张旭','男','1977-03-12','讲师','电子工程系'),('825','王萍','女','1992-05-05','助教','计算机系'),('831','刘冰','女','1993-01-20','助教','电子工程系');

--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。

--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(Class) 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)

--11、查询每门课的平均成绩。
select Cno,AVG(Degree)
from Score
where Cno='3-105' 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=(
select Cno
       from Score
       group by Cno
       having count(Cno)>=5
       )
and Cno like '3%'

--13、查询分数大于70，小于90的Sno列。

SELECT  sno from (
SELECT  sno,MIN(degree) as min_score,MAX(degree) as max_score
from score 
GROUP BY sno) a
where a.min_score>70
and a.max_score <90;

--14、查询所有学生的Sname、Cno和Degree列。
select Sname,S.Cno,S.Degree
from Student,Score S
where Student.Sno=S.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,Score,Course
where Student.Sno=Score.Sno
and Score.Cno=Course.Cno

--17、查询“95033”班学生的平均分。
select AVG(Degree)
from Student,Score
where Student.Sno=Score.Sno
and 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。

--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  a.* from student a
INNER JOIN score b
on a.sno=b.sno
where b.degree>(select degree from score xinner join course y on x.cno=y.cnowhere sno='109' and cname='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 *
from Score A
where Degree<(select MAX(Degree)
from Score B
           where A.Cno=B.Cno)
   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 student,Score
where student.Sno=Score.Sno
and Score.Degree>(select Degree
from Score
where Cno='3-105' and Sno='109')

--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(student.Sbirthday)=(select year(Sbirthday)
from student
where Sno='107')

--23、查询“张旭“教师任课的学生成绩。
select Degree
from Score,Teacher,Course
where Teacher.Tname='张旭'
and Teacher.Tno=Course.Tno
and Course.Cno=Score.Cno

select Sno,Cno,Degree
from Score
where Cno in (select Cno
from Course
           where Tno in ( 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='95033' or 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>85

--27、查询出“计算机系“教师所教课程的成绩表。
select Sno,Cno ,Degree
from Score
where Cno in (select Cno
from Course
           where Tno in (select Tno
           from Teacher
                           where Depart='计算机系'
                           )
           )

--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。
select Cno,Sno,Degree
from Score A
where (select Degree
from Score B
   where Cno='3-105' and B.Sno=A.Sno)>=(select Degree
   from Score C
                                           where Cno='3-245' and C.Sno=A.Sno)
                                           order by Degree DESC

select *
from Score
where Cno='3-105' and Degree >any(select 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 Cno,Sno,Degree
from Score A
where (select Degree
from Score B
   where Cno='3-105' and B.Sno=A.Sno)>=(select Degree
   from Score C
                                           where Cno='3-245' and C.Sno=A.Sno
                                           )
--31、查询所有教师和同学的name、sex和birthday.
select distinct Sname as name,Ssex as sex,Sbirthday as birthday
from student
UNION
select distinct Tname as name,Tsex as sex,Tbirthday as birthday
from Teacher

--32、查询所有“女”教师和“女”同学的name、sex和birthday.
select distinct Sname as name,Ssex as sex,Sbirthday as birthday
from student
where Ssex='女'
UNION
select distinct Tname as name,Tsex as sex,Tbirthday as birthday
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 Sno,Cno,Degree
from Score A
where A.Degree<(select AVG(Degree)
from Score B
where A.Cno=B.Cno)

--34、查询所有任课教师的Tname和Depart.
select Tname,Depart
from Teacher
where Tname in (select distinct Tname
from Teacher,Course,Score
where Teacher.Tno=Course.Tno and Course.Cno=Score.Cno
)

select Tname,Depart
from Teacher
where tno in (select Tno from course
where Cno in (select distinct Cno
           from Score
                           )
           )

--35、查询所有未讲课的教师的Tname和Depart.
select Tname,Depart
from Teacher
where Tname not in (select distinct Tname
from Teacher,Course,Score
where Teacher.Tno=Course.Tno and Course.Cno=Score.Cno
)

--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) as 最大,MIN(Sbirthday) as 最小 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

--42、查询最高分同学的Sno、Cno和Degree列。
select Tname,Cname
from Teacher,Course
where Tsex='男' and Teacher.Tno=Course.Tno

--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') and Sname not in ('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 Sname not in ('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,Degree
from Score
where Sno in (select Sno
from student
           where Ssex='男')
           and Cno in (select Cno
           from Course
           where Cname='计算机导论'
                       )

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