mysql sql查询
来源:互联网 发布:手机视频格式转换软件 编辑:程序博客网 时间:2024/04/27 08:21
- if Object_id('sc') is not null
- Drop table sc
- if Object_id('student') is not null
- Drop table student
- if Object_id('course') is not null
- Drop table course
- --定义SC表
- create table sc(
- sno char(20),
- cno char(20),
- grade smallint,
- primary key(sno,cno)
- );
- --定义student表
- create table student(
- sno char(10) primary key,
- sname char(20) not null,
- sage smallint,
- ssex char(2),
- sdept varchar(20)
- );
- --定义course表
- create table course(
- cno char(10) primary key,
- cname varchar(20) not null,
- credit smallint
- );
- --插入student表数据
- insert into student values('001','张三','20','f','CS');
- insert into student values('002','李晨','21','f','E');
- insert into student values('003','李丽','21','m','E');
- insert into student values('004','高飞','23','f','MA');
- insert into student values('005','苏瑞','20','f','CS');
- insert into student values('006','赵达','22','f','MA');
- insert into student values('007','韩愈','22','m','C');
- insert into student values('008','郑乐','24','m','CS');
- insert into student values('009','许三朵','23','f','MA');
- insert into student values('010','王晓','20','m','C');
- insert into student values('011','丁二','21','f','E');
- insert into student values('012','钟瑜','23','f','CS');
- insert into student values('013','刘莉莉','21','m','MA');
- insert into student values('014','柳叶青','23','f','C');
- insert into student values('015','张其安','22','m','CS');
- --插入course表信息
- insert into course values('c01','数据库','2');
- insert into course values('c02','数学','4');
- insert into course values('c03','物理','3');
- insert into course values('c04','C语言','3');
- insert into course values('c05','历史','2');
- insert into course values('c06','操作系统','3');
- insert into course values('c07','iOS开发','4');
- insert into course values('c08','软件工程','2');
- insert into course values('c09','汇编语言','2');
- insert into course values('c10','英语','3');
- --插入SC选课表
- --001学生选课
- insert into sc values('001','c02','89');
- insert into sc values('001','c04','70');
- insert into sc values('001','c08','74');
- insert into sc values('001','c10','87');
- insert into sc values('001','c03','60');
- --002学生选课
- insert into sc values('002','c01','77');
- insert into sc values('002','c03','59');
- insert into sc values('002','c02','90');
- insert into sc values('002','c04','100');
- insert into sc values('002','c05','45');
- insert into sc values('002','c06','65');
- insert into sc values('002','c07','80');
- insert into sc values('002','c08','98');
- insert into sc values('002','c09','66');
- insert into sc values('002','c10','88');
- --003学生选课
- --未选课
- --004学生选课
- insert into sc values('004','c09','90');
- insert into sc values('004','c06','43');
- insert into sc values('004','c10','85');
- insert into sc values('004','c05','86');
- insert into sc values('004','c07','60');
- insert into sc values('004','c08','78');
- --005学生选课
- insert into sc values('005','c10','88');
- insert into sc values('005','c02','69');
- insert into sc values('005','c04','84');
- insert into sc values('005','c05','88');
- insert into sc values('005','c03','65');
- insert into sc values('005','c06','70');
- insert into sc values('005','c07','81');
- --006学生选课
- insert into sc values('006','c10','62');
- insert into sc values('006','c02','87');
- insert into sc values('006','c04','60');
- insert into sc values('006','c05','74');
- insert into sc values('006','c03','63');
- insert into sc values('006','c06','70');
- insert into sc values('006','c07','91');
- insert into sc values('006','c01','70');
- insert into sc values('006','c09','81');
- --007学生选课
- insert into sc values('007','c01','80');
- insert into sc values('007','c02','67');
- insert into sc values('007','c04','62');
- insert into sc values('007','c05','74');
- insert into sc values('007','c03','45');
- insert into sc values('007','c08','68');
- insert into sc values('007','c09','99');
- insert into sc values('007','c10','100');
- --008学生选课
- insert into sc values('008','c08','61');
- insert into sc values('008','c02','82');
- insert into sc values('008','c04','88');
- --009学生选课
- insert into sc values('009','c02','67');
- insert into sc values('009','c06','34');
- insert into sc values('009','c08','78');
- insert into sc values('009','c10','74');
- insert into sc values('009','c03','80');
- insert into sc values('009','c04','70');
- insert into sc values('009','c07','94');
- --010学生选课
- insert into sc values('010','c10','80');
- insert into sc values('010','c02','84');
- insert into sc values('010','c04','65');
- insert into sc values('010','c05','72');
- insert into sc values('010','c03','87');
- insert into sc values('010','c08','70');
- insert into sc values('010','c07','91');
- insert into sc values('010','c01','70');
- insert into sc values('010','c09','81');
- --011学生选课
- insert into sc values('011','c04','64');
- insert into sc values('011','c07','75');
- insert into sc values('011','c09','60');
- insert into sc values('011','c02','84');
- --012学生选课
- insert into sc values('012','c01','97');
- insert into sc values('012','c02','83');
- insert into sc values('012','c03','60');
- insert into sc values('012','c04','70');
- insert into sc values('012','c05','88');
- insert into sc values('012','c06','64');
- insert into sc values('012','c07','91');
- insert into sc values('012','c08','70');
- insert into sc values('012','c09','84');
- insert into sc values('012','c10','81');
- --013学生选课
- insert into sc values('013','c01','95');
- insert into sc values('013','c02','86');
- insert into sc values('013','c04','70');
- insert into sc values('013','c06','57');
- insert into sc values('013','c08','63');
- insert into sc values('013','c10','54');
- --014学生选课
- insert into sc values('014','c01','78');
- insert into sc values('014','c02','87');
- insert into sc values('014','c03','75');
- insert into sc values('014','c05','99');
- insert into sc values('014','c06','34');
- insert into sc values('014','c07','48');
- insert into sc values('014','c09','84');
- insert into sc values('014','c10','89');
- --015学生选课
- insert into sc values('015','c02','87');
- insert into sc values('015','c07','96');
--以下是老师布置的练习题,我觉得做完以后大有收获,拿出来大家交流一下
1、在Course表中添加“教师”列(20个长度的变长字符串)
2、为每门课程添加教师信息。
3、将教师列修改为非空列。
4、查询选修了刘老师的课程的学生。
5、检索选修了课程号为C01或C02课程,且成绩高于或等于70分的学生的姓名,课程名和成绩。
6、检索所有学生的姓名、所选课程的课程名和成绩以及课程号,并且按成绩的降序和课程号的升序进行排列。
7. 列出没有选课的学生姓名
8. 列出平均分最高的学生所在系的所有学生的姓名
9.查询CS系C01课程的成绩比C01课程的平均分高的学生学号
10.查询既选修了C01又选修了C02的学生
11.统计及格的课程数在四门以上的学生所选课程的平均成绩。最后按降序列出平均成绩名次名单来。
12.检索所有CS系学生都选修了的课程(列出课程号)
13.查询年龄高于其所在系的平均年龄的学生姓名
14.查询每位同学的选课中成绩最高的课程对应的学号,姓名,课程名,成绩
15.为MA系学生选修必修课C05
16.将CS系,C01课程学生的成绩加10分
17.将每位同学的最低分加10分(选)
18.将”数据库”的选课记录全部删除
[sql] view plain copy
- --1、检索所有学生中年龄最大的学生的姓名及年龄。
- select sno,sname from student
- where sage=(select max(sage) from student)
- select sno,sname from student
- where sage>=all(select sage from student)
- --2、求每一个学生的最高分和最低分。
- select sno,max(grade) as '最高分',min(grade) as '最低分'from sc
- group by sno;
- select sno,grade from sc
- where grade>=all(select grade from student) or grade<=all(select grade from student)
- --3、查询CS系所有男同学考C05课程的成绩,列出这些学生的学号,姓名,成绩,并按成绩降序排列。
- select student.sno,sname,grade from sc,student
- where sdept='CS' and cno='c05'
- and student.sno =sc.sno
- order by grade desc;
- select sno,grade from sc
- where sno in(select sno from student where sdept='cs')and cno='c05'
- order by grade desc;
- --4、检索选修了“C语言”课程的学生的姓名(可用子查询—IN或Exists)
- --子查询in
- select sname from student
- where sno in(
- select sno from sc
- where cno in (
- select cno from course where cname='C语言'))
- --子查询exists
- select sname from student
- where exists(
- select * from sc
- where sno=student.sno and exists(
- select * from course where cno=sc.cno and cname='C语言'
- )
- )
- select sname from student,sc
- where sc.sno=student.sno and cno=(select cno from course where cname='C语言')
- --5、检索选修了课程号为C01或C02课程,且成绩高于或等于70分的学生的姓名,课程名和成绩。
- select sname,cname,grade from student,sc,course
- where student.sno=sc.sno
- and sc.cno=course.cno
- and sc.cno in('c01','c02') and grade>=70;
- --6、检索所有学生的姓名、所选课程的课程名和成绩以及课程号,并且按成绩的降序和课程号的升序进行排列(使用外连接将没有选课的同学列出来)。
- select sname,sc.cno,grade from course,student, sc
- where student.sno=sc.sno and course.cno=sc.cno
- order by grade desc;
- --7. 列出没有选课的学生姓名
- select sno,sname from student
- where sno not in(select sno from sc)
- select sno,sname from student
- where not exists(select sno from sc where sno=student.sno)
- --8. 列出平均分最高的学生所在系的所有学生的姓名
- select sname,sdept from student
- where sdept in(
- select sdept from student
- where sno in(
- select sno from sc
- group by sno
- having avg(grade)>=all(select avg(grade)from sc group by sno))
- )
- --9.查询CS系C01课程的成绩比C01课程的平均分高的学生学号
- select student.sno from student,sc
- where sc.sno=student.sno and sdept='CS'and sc.cno='c01'and grade>
- (select avg(grade) from sc
- where cno='c01');
- --10.查询既选修了C01又选修了C02的学生
- --in
- select sno from student
- where sno in(select sno from sc where cno='c01') and sno in(select sno from sc where cno='c02')
- select sno from student
- where exists(select sno from sc where cno='c01' and sno=student.sno) and sno in(select sno from sc where cno='c02'and sno=student.sno)
- select sno from student
- where sno in(select sno from sc
- where cno='c01'
- intersect
- select sno from sc
- where cno='c02')
- --11.统计及格的课程数在四门以上的学生所选课程的平均成绩。最后按降序列出平均成绩名次名单来。
- select sno,avg(grade) from sc
- where grade>=60
- group by sno
- having count(*)>4
- order by avg(grade) desc;
- --12.检索所有CS系学生都选修了的课程(列出课程号)
- select cno from sc,student
- where sc.sno=student.sno and student.sdept='CS'
- group by cno
- having count(*)=(select count(*) from student where sdept='CS')
- select cno from course
- where not exists(
- select * from student
- where sdept='CS' and not exists(
- select * from sc
- where student.sno=sc.sno and course.cno=sc.cno
- )
- )
- --没有选课的学生
- select sno from student
- where not exists(
- select * from sc where sc.sno=student.sno
- )
- --13.查询年龄高于其所在系的平均年龄的学生姓名
- select sname from student x
- where sage>(select avg(sage) from student y where x.sdept=y.sdept)
- --14.查询每位同学的选课中成绩最高的课程对应的学号,姓名,课程名,成绩
- select sc.sno,sname,cname,grade from sc,student,course
- where sc.sno=student.sno and sc.cno=course.cno
- and grade=(select max(grade) from sc where sc.sno=student.sno)
- select sc.sno,sname,cname,grade from sc,student,course
- where sc.sno=student.sno and sc.cno=course.cno
- and grade>=all(select grade from sc where student.sno=sc.sno)
- --创建视图然后查询
- create view s1(sno,sname,cname,grade)
- as
- select sc.sno,sname,cname,grade from sc,student,course
- where sc.sno=student.sno and course.cno=sc.cno
- --select sno,sname,max(grade) from s1
- --group by (sno,sname)
- --15.为MA系学生选修必修课C05
- insert into sc(sno,cno)
- select sno,'c05' from student
- where sdept = 'MA' and
- sno not in (select sno from sc where cno='c05')
- insert into sc(sno,cno)
- select sno,'c05' from student
- where sdept='MA' and not exists(select sno from sc where cno='c05' and sno=student.sno )
- --16.将CS系,C01课程学生的成绩加10分
- update sc
- set grade=grade-10
- where cno='c01' and sno in(select sno from student where sdept='CS')
- select * from sc,student
- where cno='c01' and student.sno=sc.sno and student.sdept='CS'
- --17.将每位同学的最低分加10分(选)
- update sc
- set grade=grade+10
- where grade=(select min(grade) from sc y where sc.sno=y.sno)
- update sc
- set grade=grade-10
- where grade=(select min(grade) from sc y
- group by sno
- having sc.sno=y.sno
- )
- --18.将”数据库”的选课记录全部删除
- delete from sc
- where '数据库'=(select cname from course where sc.cno=course.cno);
- delete from sc
- where cno=(select cno from course where course.cname='数据库');
0 0
- MYSQL /SQL 查询 日期
- SQL查询MySQL笔记
- mysql--sql查询练手
- MySQL多表SQL查询
- MySQL多表SQL查询
- mysql sql执行时间查询
- mysql sql查询
- sql 子查询(mysql)
- mysql进程查询sql
- mysql sql 子查询
- MySQL 查询处理 SQL查询执行顺序
- mysql sql语句执行时间查询
- mysql之SQL查询过程
- mysql之SQL查询原理
- MySQL常用SQL查询语句
- mysql 查询表结构SQL
- 查询mysql数据库结构sql
- SQL查询、排序(mysql下)
- (四)PHP注释,运算符
- 纯干货,Spring-data-jpa详解,全方位介绍。
- MFC ComBox 控件 调节下拉大小
- INI配置文件读写工具类
- ipv6网段 防火墙 转发功能分析
- mysql sql查询
- MongoDB基本操作
- Xcode import CocoaPods 中的第三方库时不提示
- qt中,如何用QLabel显示一个变量!
- Java中普通代码块,构造代码块,静态代码块区别及代码示例
- 有关css清空样式比较全的总结
- 代码重构和优化一
- bitnami gitlab修改密码
- POJ 1775 FZU 1106 LightOJ 1189 Sum of Factorials