数据库实验报告

用SQL语句和企业管理器建立如下的表结构并输入数据
给定表结构如下：



创建数据库

创建数据库
create table student(
	Sno int auto_increment primary key,
    Sname varchar(45),
    Ssex varchar(45),
    Sage int,
    Sdept varchar(45)
)engine = InnoDB default charset=utf8;
create table Course(
	Cno int auto_increment primary key,
    Cname varchar(45),
    Cpno int,
    Ccredit int
) engine = InnoDB default charset=utf8;

create table SC(
	Sno int ,
    Cno int ,
    Grade int,
    primary key(Sno,Cno),
    constraint c_fk foreign key(Sno)references student(Sno),
    constraint c_fk21 foreign key(Cno) references Course(Cno)
        
) engine = InnoDB default charset=utf8;

（1）Course表插入数据：
SELECT * FROM Student.Course;
insert into Course values(1,"数据库",5,4);
insert into Course (Cno,Cname,Ccredit) values(2,"数学",2);
insert into Course values(3,"信息系统",1,4);
insert into Course values(4,"操作系统",6,3);
insert into Course values(5,"数据结构",7,4);
insert into Course (Cno,Cname,Ccredit) values(6,"数据处理",2);
insert into Course values(7,"PASCAL语言",6,4);
（2）SC表插入数据：
SELECT * FROM Student.SC;
insert into SC values(95001,1,92);
insert into SC values(95001,2,85);
insert into SC values(95001,3,88);
insert into SC values(95002,2,90);
insert into SC values(95002,3,85);
insert into SC values(95003,3,59);
（3）student表插入数据
SELECT * FROM Student.student;
insert into student values(95001,"李勇","男",20,"CS");
insert into student values(95002,"刘晨","女",21,"lS");
insert into student values(95003,"王敏","女",18,"MA");
insert into student values(95004,"张力","男",19,"lS");

用SQL语句完成一下的要求：

• 1.查询信息系（IS）的所有学生信息

1.select * from student where Sdept="lS"

• 2.查询选5.查询所有姓王的学生。

 2.select * from Course where Cname="数学";

• 3.查询至少选修了一门其直接先行课为5号课程的学生的姓名。

3.select Sname from student,SC,Course where Course.Cpno="5" and SC.Cno=Course.Cno and SC.Sno=student.Sno;

• 4.查询全体学生的姓名和出生年份。

4.select Sname,2018-Sage from student;

• 5.查询所有姓王的学生。

5.select Sname from student where Sname like '王%'

• 6.查询选修了3号课程的学生姓名及成绩，并按成绩降序排序。

6.select Sname,Grade from student ,SC where Cno='3'and SC.Sno=student.Sno order by Grade     desc;

• 7.查询全体学生情况，查询结果按所在系的系号升序排列，同一系中的学生按年龄降序排列。

7.select * from student order by Sdept asc ,Sage desc;

• 8.计算2号课程的平均成绩。

8.select avg(Grade) avg2 from SC where SC.Cno='2';

• 9.查询选修了2号课程的学生的最高成绩。

9.select max(Grade) from SC where SC.Cno='2';

• 10.求各个课程号及相应的选课人数。

10.select Cno,count(Sno) from SC group by Cno;

• 11.查询至少选修了3门课程以上的学生学号。

11.select Sno from SC group by Sno having count(Cno)>=3;

• 12.查询“数据库”的间接先行课。

12.select Cname from Course where Cno=(select Cpno from Course where Cname='数据库');

• 13.查询平均成绩最高的学生的学号和姓名。

13.select student.Sno,Sname from student,SC
where  SC.Sno=student.Sno and Grade in (select max(Grade) from SC);

• 14.查询数学成绩最高的学生的学号和姓名。

14.select student.Sno,Sname from SC,student where  SC.Sno=student.Sno and
Grade in (select max(Grade) from SC,Course where SC.Cno=Course.Cno and Course.Cname="数学") ;

• 15.查询出成绩最低学号最大的学生学号。

15.select Sno from SC where Grade in (select min(Grade) from SC) and Sno in (select max(Sno) from SC);

• 16.查询成绩高于学生平均成绩的记录。

16.select * from SC where  Grade > (select avg(Grade) from SC);

• 17.查询至少选修了1号课程和3号课程的学生学号。

17.select Sno from SC where Sno in (select Sno from SC where Cno=1 ) and Cno=3;

• 18.查询只选修了1号课程和3号课程的学生学号。

18.select Sno from SC where Cno = 1 and 3 and not exists (select Sno from SC where Cno=2) ;

• 19.查询没有选修1号课程的学生姓名。

19. SELECT Sname from student where not exists (select * from SC WHERE Sno=student.Sno and Cno='1');

• 20.查询选修了全部课程的学生姓名。

20.select Sname from student  where Sno IN (select Sno from SC group by Sno having count(*) = (select count(*) from Course ));    

• 21.查询至少选修了95002所选修的全部课程的学生学号。

21. select distinct Sno from SC where Sno  in(select  Sno from SC s1 where not exists(select * from SC s2 where s2.Sno='95002' and not exists(select * from SC s3 where s1.Sno=s3.Sno and s2.Cno=s3.Cno)));

• 22.查询没有不及格课程的学生的学号和姓名。

22.select distinct SC.Sno,Sname from SC ,student where Grade>60 and SC.Sno =student.Sno;

• 23.查询没有不及格学生的课程的课程号和课程名。

23.select distinct SC.Cno, Cname from SC ,Course where Grade>60 and SC.Cno = Course.Cno;

• 24.建立信息系学生视图，并从视图中查询年龄最大的学生记录。

24.create view is_student(a_Sno,a_Sname,a_Sage)as select Sno ,Sname ,Sage from student where Sdept ='lS';
select * from is_student where a_Sage in (select max(a_Sage) from is_student);