SQL基础实例（学生课程系统）
drop table student,course,score,teacher
CREATE TABLE STUDENT --学生表
(SNO VARCHAR(3) NOT NULL, --学号
SNAME nVARCHAR(4) NOT NULL, --姓名
SSEX nVARCHAR(2) NOT NULL, --性别
SBIRTHDAY DATETIME, --出生年月
CLASS VARCHAR(5)) --班级编号
go
CREATE TABLE COURSE --课程表
(CNO VARCHAR(5) NOT NULL, --课程ID
CNAME nVARCHAR(10) NOT NULL, --课程名称
TNO VARCHAR(10) NOT NULL) --教师ID
go
CREATE TABLE SCORE --成绩表
(SNO VARCHAR(3) NOT NULL, --成绩ID
CNO VARCHAR(5) NOT NULL, --课程编号
DEGREE NUMERIC(10, 1) NOT NULL) --分数
go
CREATE TABLE TEACHER --教师表
(TNO VARCHAR(3) NOT NULL, --教师ID
TNAME nVARCHAR(4) NOT NULL, --教师姓名
TSEX nVARCHAR(2) NOT NULL, --性别
TBIRTHDAY DATETIME NOT NULL, --出生年月
PROF nVARCHAR(6), --级称
DEPART nVARCHAR(10) NOT NULL) --所属系部
go
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,N'曾华' ,N'男' ,1977-09-01,'95033');
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,N'匡明' ,N'男' ,1975-10-02,'95031');
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,N'王丽' ,N'女' ,1976-01-23,'95033');
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,N'李军' ,N'男' ,1976-02-20,'95033');
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,N'王芳' ,N'女' ,1975-02-10,'95031');
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,N'陆君' ,N'女' ,1974-06-03,'95031');
GO
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-105' ,N'计算机导论',825)
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-245' ,N'操作系统' ,804);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('6-166' ,N'数据电路' ,856);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('9-888' ,N'高等数学' ,100);
GO
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-245',86);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-245',75);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-245',68);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-105',92);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-105',88);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-105',76);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'3-105',64);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'3-105',91);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'3-105',78);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'6-166',85);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'6-166',79);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'6-166',80);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'6-166',82);
GO
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART)
VALUES (804,N'李诚',N'男','1958-12-02',N'副教授',N'计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART)
VALUES (856,N'张旭',N'男','1969-03-12',N'讲师',N'电子工程系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART)
VALUES (825,N'王萍',N'女','1972-05-05',N'助教',N'计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART)
VALUES (831,N'刘冰',N'女','1977-08-14',N'助教',N'电子工程系');
go
--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)
select * from score where degree =85 or degree = 86 or degree = 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= N'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 distinct s.Sno,c.Cno from student as s,course as c ,score as sc
where s.sno=(select sno from score where degree = (select max(degree) from score))
and c.cno = (select 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%' 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 from score group by sno having min(degree) > 70 and max(degree) < 90
select distinct sno from score a where(select min(degree) from score where sno = a.sno) > 70 and
(select max(degree) from score where sno = a.sno) < 90
--=================================
go
--14、查询所有学生的Sname、Cno和Degree列。
select s.sname,sc.cno,sc.degree from student as s,score as sc where s.sno = sc.sno
--15、查询所有学生的Sno、Cname和Degree列。
select sc.sno,c.cname,sc.degree from course as c,score as sc where c.cno = sc.cno
--16、查询所有学生的Sname、Cname和Degree列。
select s.sname,c.cname,sc.degree from student as s,course as c,score as sc where s.sno = sc.sno and c.cno = sc.cno
--17、查询“95033”班所选课程的平均分。
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 numeric(3,0),upp numeric(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')
commit;
--================go
select * from student
select * from course
select * from score
select * from teacher
select * from grade
-- 现查询所有同学的Sno、Cno和rank列。
select sno,cno,
(case when degree>90 then 'A'
when degree>80 then 'B'
when degree>70 then 'C'
when degree>60 then 'D'
else 'E' end)
from score
--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 student where sno in(select sno from score where degree >
(select degree from score where sno='109' and cno='3-105'))
--20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录。
select sno,degree from score a where not exists
(select * from score where sno = a.sno and degree < a.degree)
select sno,degree from score
select sno,degree from score a where sno in (select sno from score group by sno having count(distinct cno) > 1 )
and degree < (select max(degree) from score where sno = a.sno)
--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 where sno in (select distinct sno from score where degree >
(select max(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) = (select year(sbirthday) from student where sno = '108')
--23、查询“张旭“教师任课的学生成绩。
--select tno from teacher where tname = N'张旭'
--select cno from course where tno = (select tno from teacher where tname = N'张旭')
select * from score where cno = (select cno from course where tno = (select tno from teacher where tname = N'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(sno)>5
select t.tname from teacher t,course c where t.tno = c.tno and c.cno =
(select cno from score group by cno having count(sno)>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 * from score where cno in (select cno from course where tno in (select tno from teacher where depart = N'计算机系'))
select * from course
select * from teacher
select * from score
--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 = N'计算机系' or depart = N'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。
select * from score where 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.
select * from score where degree > (select min(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 * from student
select * from teacher
--32、查询所有“女”教师和“女”同学的name、sex和birthday.
select * from student where ssex = N'女'
select * from teacher where Tsex = N'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 t1 where degree<(select avg(degree) from score t2 where t2.cno=t1.cno)
select * from
score a
left join
(select CNO,sum(DEGREE)/count(1)de from score group by CNO)b
on b.cno=a.cno
where b.de>a.degree
--========================================
--34、查询所有任课教师的Tname和Depart.
select * from teacher
--35 查询所有未讲课的教师的Tname和Depart.
select t.* from teacher t where not exists (select 1 from course where tno = t.tno )
select * from teacher where tno not in (select tno from course)
--36、查询至少有2名男生的班号。
select class from student where ssex = N'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 N'王%'
--38、查询Student表中每个学生的姓名和年龄。
select sname,年龄 = datediff(year,sbirthday,getdate()) from student
--39、查询Student表中最大和最小的Sbirthday日期值。
select max(sbirthday) from student
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 * from student order by class DESC,sbirthday DESC
--41、查询“男”教师及其所上的课程。
select c.* from course c,teacher t where t.tno = c.tno and t.tsex = N'男'
--42、查询最高分同学的Sno、Cno和Degree列。
select sno, max(degree) from score group by sno
--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 = N'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 = N'李军') and
class = (select class from student where sname = N'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 = (select cno from course where cname = N'计算机导论')
and sno in (select sno from student where ssex = N'男')
青华木园
青华木园
