标签:INSERT PostgreSQL INTO VALUES student sc null
PostgreSQL练习
建表
--department(dNo,dName,officeRoom,homepage)
--student(sNo,sName,sex,age,dNo)
--course(cNo,cName,cPNo,credit,dNo)
--sc(sNo,cNo,score,recordDate)
CREATE TABLE department(
dNo CHAR(2) NOT NULL UNIQUE,
dName VARCHAR(20),
officeRoom VARCHAR(40),
homePage VARCHAR(80),
PRIMARY KEY(dNo)
);
CREATE TABLE student(
sNo CHAR(6) NOT NULL UNIQUE,
sName VARCHAR(20) NOT NULL,
sex CHAR(2) CHECK (sex IN('男','女')),
age INT,
dNo CHAR(2),
PRIMARY KEY(sNo),
FOREIGN KEY (dNo) REFERENCES department(dNo)
);
CREATE TABLE course(
cNo CHAR(6) NOT NULL UNIQUE,
cName VARCHAR(20) NOT NULL,
cPNo CHAR(6),
credit INT,
dNo CHAR(2),
PRIMARY KEY(cNo),
FOREIGN KEY (cPNo) REFERENCES course(cNo),
FOREIGN KEY (dNo) REFERENCES department(dNo)
);
CREATE TABLE sc(
sNo CHAR(6) NOT NULL,
cNo CHAR(6) NOT NULL,
score INT,
recordDate date DEFAULT current_date,
PRIMARY KEY(sNo,cNo),
FOREIGN KEY (sNo) REFERENCES student(sNo),
FOREIGN KEY (cNo) REFERENCES course(cNo)
);
插入数据
INSERT INTO department VALUES('01','信息学院','行政楼409','www.xxx.edu.cn');
INSERT INTO department VALUES('02','软件学院',null,null);
INSERT INTO department VALUES('03','理学院',null,null);
INSERT INTO department VALUES('04','文学院',null,null);
INSERT INTO department VALUES('05','外国语学院',null,null);
INSERT INTO student VALUES('170101','宁灿', '女',19,'01');
INSERT INTO student VALUES('170102','尹江月','女',19,'01');
INSERT INTO student VALUES('170103','杨佳伟','男',null,null);
INSERT INTO student VALUES('170104','杨何宇','男',19,'01');
INSERT INTO student VALUES('170105','胡耀斌','男',19,null);
INSERT INTO student VALUES('170106','李杨阳','女',20,'01');
INSERT INTO student VALUES('170107','杜利俊','女',18,'01');
INSERT INTO student VALUES('170108','钱多多','女',17,'01');
INSERT INTO student VALUES('170109','李佳伟','女',null,'01');
INSERT INTO student VALUES('170110','吴莫愁','女',21,'01');
INSERT INTO student VALUES('170201','安相成','男',19,'02');
INSERT INTO student VALUES('170202','曹师好','男',null,'02');
INSERT INTO student VALUES('170203','雷霆', '男',18,'02');
INSERT INTO student VALUES('170204','刘书敏','男',20,'02');
INSERT INTO student VALUES('170205','王兵', '男',21,'02');
INSERT INTO student VALUES('170206','李佳成','男',19,null);
INSERT INTO student VALUES('170207','唐玉迎','女',17,'02');
INSERT INTO student VALUES('170208','杨曼婷','女',19,'02');
INSERT INTO student VALUES('170301','张望', '男',21,'03');
INSERT INTO student VALUES('170302','王芳', '女',18,'03');
INSERT INTO student VALUES('170303','赵四海','男',19,'03');
INSERT INTO student VALUES('170401','孙敏', '女',null,null);
INSERT INTO student VALUES('170402','李忠国','男',null,'04');
INSERT INTO student VALUES('170403','钱紧', '男',17,'04');
INSERT INTO student VALUES('170404','钱多多','女',20,'04');
INSERT INTO student VALUES('170405','管八方','男',21,'04');
INSERT INTO student VALUES('170406','王兵', '男',19,'04');
INSERT INTO student VALUES('170407','张三丰','男',100,null);
INSERT INTO course VALUES('030101','高等数学',null,2,'03');
INSERT INTO course VALUES('030102','线性代数',null,2,'03');
INSERT INTO course VALUES('030201','矩阵论','030102',3,'03');
INSERT INTO course VALUES('030202','概率论','030101',2,'03');
INSERT INTO course VALUES('030301','数理统计','030202',3,'03');
INSERT INTO course VALUES('010101','信号与系统',null,2,'01');
INSERT INTO course VALUES('010102','数字电路','010101',2,'01');
INSERT INTO course VALUES('010103','数字信号处理','030301',3,'01');
INSERT INTO course VALUES('010201','模式识别','010103',3,'01');
INSERT INTO course VALUES('020101','离散数学',null,2,'02');
INSERT INTO course VALUES('020102','程序设计基础',null,2,'02');
INSERT INTO course VALUES('020201','计算机组成原理','020101',3,'02');
INSERT INTO course VALUES('020202','面向对象程序设计','020102',2,'02');
INSERT INTO course VALUES('020203','编译原理','020101',2,'02');
INSERT INTO course VALUES('020301','数据结构','020202',3,'02');
INSERT INTO course VALUES('020302','操作系统','020201',3,'02');
INSERT INTO course VALUES('020401','数据库系统','020301',3,'02');
INSERT INTO course VALUES('020402','算法设计与分析','020301',3,'02');
INSERT INTO course VALUES('020403','形式语言与自动机','020203',3,'02');
INSERT INTO course VALUES('020501','移动计算','020102',2,'02');
INSERT INTO course VALUES('040101','中国传统文化',null,1,'04');
INSERT INTO course VALUES('040102','近代世界史',null,1,'04');
INSERT INTO course VALUES('040103','现代文学',null,1,'04');
INSERT INTO course VALUES('040201','古典文学欣赏','040101',2,'04');
INSERT INTO course VALUES('040202','世界文学','040103',2,'04');
INSERT INTO course VALUES('040301','中国诗词欣赏','040201',2,'04');
INSERT INTO sc VALUES ('170101','030101',91,to_date('2016-01-08','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170101','030102',83,to_date('2016-07-10','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170101','020101',88,to_date('2016-07-02','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170101','020102',92,to_date('2017-01-10','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170101','020201',70,to_date('2017-01-10','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170101','020202',80,to_date('2017-01-10','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170101','020203',null,null);
INSERT INTO sc VALUES ('170101','020301',null,null);
INSERT INTO sc VALUES ('170101','020302',null,null);
INSERT INTO sc VALUES ('170101','020401',null,null);
INSERT INTO sc VALUES ('170101','020402',null,null);
INSERT INTO sc VALUES ('170102','030101',88,to_date('2016-01-08','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170102','030102',86,to_date('2016-07-10','yyyy-mm-dd'));
INSERT INTO sc VALUES ('170102','030201',58,null);
INSERT INTO sc VALUES ('170102','030202',90,null);
INSERT INTO sc VALUES ('170102','030301',70,null);
INSERT INTO sc VALUES ('170102','010101',85,null);
INSERT INTO sc VALUES ('170102','010102',68,null);
INSERT INTO sc VALUES ('170102','010103',80,null);
INSERT INTO sc VALUES ('170102','010201',78,null);
INSERT INTO sc VALUES ('170103','030101',88,default);
INSERT INTO sc VALUES ('170103','030102',80,default);
INSERT INTO sc VALUES ('170103','030202',76,default);
INSERT INTO sc VALUES ('170103','010101',90,default);
INSERT INTO sc VALUES ('170103','010102',83,null);
INSERT INTO sc VALUES ('170103','010103',55,null);
INSERT INTO sc VALUES ('170103','010201',77,null);
INSERT INTO sc VALUES ('170104','030101',null,null);
INSERT INTO sc VALUES ('170105','030101',null,null);
INSERT INTO sc VALUES ('170108','030101',90,null);
INSERT INTO sc VALUES ('170108','030102',87,null);
INSERT INTO sc VALUES ('170108','030202',78,null);
INSERT INTO sc VALUES ('170108','010101',57,null);
INSERT INTO sc VALUES ('170108','010102',56,null);
INSERT INTO sc VALUES ('170108','010103',54,null);
INSERT INTO sc VALUES ('170108','010201',50,null);
INSERT INTO sc VALUES ('170110','030101',90,default);
INSERT INTO sc VALUES ('170110','030102',90,default);
INSERT INTO sc VALUES ('170110','010101',88,default);
INSERT INTO sc VALUES ('170110','010102',88,default);
INSERT INTO sc VALUES ('170110','010103',77,default);
INSERT INTO sc VALUES ('170201','030101',88,null);
INSERT INTO sc VALUES ('170201','030102',83,null);
INSERT INTO sc VALUES ('170201','020101',79,null);
INSERT INTO sc VALUES ('170201','020102',84,null);
INSERT INTO sc VALUES ('170201','020201',75,null);
INSERT INTO sc VALUES ('170201','020202',80,null);
INSERT INTO sc VALUES ('170201','020301',82,null);
INSERT INTO sc VALUES ('170201','020302',53,null);
INSERT INTO sc VALUES ('170201','020401',78,null);
INSERT INTO sc VALUES ('170201','020402',58,null);
INSERT INTO sc VALUES ('170202','030101',86,null);
INSERT INTO sc VALUES ('170202','030102',82,null);
INSERT INTO sc VALUES ('170202','020101',90,null);
INSERT INTO sc VALUES ('170202','020102',85,null);
INSERT INTO sc VALUES ('170202','020201',80,null);
INSERT INTO sc VALUES ('170202','020202',78,null);
INSERT INTO sc VALUES ('170202','020203',75,null);
INSERT INTO sc VALUES ('170202','020301',70,null);
INSERT INTO sc VALUES ('170202','020302',68,null);
INSERT INTO sc VALUES ('170202','020401',80,null);
INSERT INTO sc VALUES ('170202','020402',56,null);
INSERT INTO sc VALUES ('170203','030101',null,null);
INSERT INTO sc VALUES ('170203','030102',null,null);
INSERT INTO sc VALUES ('170205','030101',80,null);
INSERT INTO sc VALUES ('170205','030102',55,null);
INSERT INTO sc VALUES ('170205','020101',50,null);
INSERT INTO sc VALUES ('170205','020102',96,null);
INSERT INTO sc VALUES ('170205','020201',80,null);
INSERT INTO sc VALUES ('170205','020202',85,null);
INSERT INTO sc VALUES ('170205','020203',60,null);
INSERT INTO sc VALUES ('170205','020301',88,null);
INSERT INTO sc VALUES ('170205','020302',92,null);
INSERT INTO sc VALUES ('170205','020401',65,null);
INSERT INTO sc VALUES ('170205','020402',70,null);
INSERT INTO sc VALUES ('170205','020501',80,null);
INSERT INTO sc VALUES ('170207','030101',null,null);
INSERT INTO sc VALUES ('170207','030102',null,null);
INSERT INTO sc VALUES ('170208','030101',60,null);
INSERT INTO sc VALUES ('170208','030102',null,null);
INSERT INTO sc VALUES ('170208','020101',null,null);
INSERT INTO sc VALUES ('170208','020102',null,null);
INSERT INTO sc VALUES ('170208','020201',null,null);
INSERT INTO sc VALUES ('170208','020202',null,null);
INSERT INTO sc VALUES ('170208','020301',null,null);
INSERT INTO sc VALUES ('170208','020302',null,null);
INSERT INTO sc VALUES ('170208','020401',null,null);
INSERT INTO sc VALUES ('170208','020402',null,null);
INSERT INTO sc VALUES ('170208','020501',null,null);
INSERT INTO sc VALUES ('170303','030101',90,null);
INSERT INTO sc VALUES ('170303','030102',88,null);
INSERT INTO sc VALUES ('170303','030201',92,null);
INSERT INTO sc VALUES ('170303','030202',93,null);
INSERT INTO sc VALUES ('170303','030301',94,null);
INSERT INTO sc VALUES ('170401','040101',82,null);
INSERT INTO sc VALUES ('170401','040102',80,null);
INSERT INTO sc VALUES ('170401','040103',83,null);
INSERT INTO sc VALUES ('170401','040201',89,null);
INSERT INTO sc VALUES ('170401','040202',70,null);
INSERT INTO sc VALUES ('170401','040301',null,null);
INSERT INTO sc VALUES ('170403','040201',95,null);
INSERT INTO sc VALUES ('170403','040202',88,null);
INSERT INTO sc VALUES ('170403','040301',80,null);
INSERT INTO sc VALUES ('170404','040101',95,null);
INSERT INTO sc VALUES ('170404','040102',91,null);
INSERT INTO sc VALUES ('170404','040103',89,null);
INSERT INTO sc VALUES ('170404','040201',93,null);
INSERT INTO sc VALUES ('170404','040202',92,null);
INSERT INTO sc VALUES ('170404','040301',88,null);
INSERT INTO sc VALUES ('170405','040102',70,null);
INSERT INTO sc VALUES ('170405','040201',58,null);
INSERT INTO sc VALUES ('170405','040202',66,null);
INSERT INTO sc VALUES ('170405','040301',77,null);
INSERT INTO sc VALUES ('170406','040101',55,null);
INSERT INTO sc VALUES ('170406','040102',65,null);
INSERT INTO sc VALUES ('170406','040301',75,null);
练习1 单表查询
- 查询所有年龄大于等于20岁的学生学号、姓名;
select sno,sname
from student
where age >= 20;
- 查询所有姓钱的男生学号、姓名、出生年份;
select sno,sname,2020-age
from student
where sname like '钱%' and sex = '男';
LIKE操作符的模式匹配
- 查询所有学分大于3的课程名称;
select cname
from course
where credit > 3;
- 查询所有没有被分配到任何学院的学生姓名;
select sname
from student
where dno is null;
- 查询所有尚未设置主页的学院名称;
select dname
from department
where homepage is null;
练习2 聚集函数
- 查询各个学院的平均年龄;
select avg(age)
from student
group by dno;
- 查询每个学生选修课程的平均分;
select sno,avg(score)
from sc
group by sno
having avg(score) is not null
order by avg(score) desc;
order by 列名 序;
- 查询各课程的平均分;
select cno,avg(score)
from sc
group by cno
having avg(score) is not null
order by avg(score) desc;
- 查询各学院开设的课程门数;
select dno,count(cno)
from course
where cno is not null
group by dno
order by count(cno) desc;
- 查询各门课程选修人数;
select cno,count(sno)
from sc
where cno is not null and sno is not null
group by cno
order by count(sno) desc;
练习3 多表查询
- 查询“信息学院”所有学生学号与姓名;
- 查询“软件学院”开设的所有课程号与课程名称;
- 查询与“陈丽”在同一个系的所有学生学号与姓名;
- 查询与“张三”同岁的所有学生学号与姓名;
- 查询与“张三”同岁且不与“张三”在同一个系的学生学号与姓名;
- 查询学分大于“离散数学”的所有课程名称;
- 查询选修了课程名为“组合数学”的学生人数;
- 查询没有选修“离散数学”的学生姓名;
- 查询与“算法设计与分析”、“移动计算”学分不同的所有课程名称;
- 查询平均分大于等于90分的所有课程名称;
- 查询选修了“离散数学”课程的所有学生姓名与成绩;
- 查询“王兵”所选修的所有课程名称及成绩;
- 查询所有具有不及格课程的学生姓名、课程名与成绩;
- 查询选修了“文学院”开设课程的所有学生姓名;
- 查询“信息学院”所有学生姓名及其所选的“信息学院”开设的课程名称;
练习4 综合查询
- 查询所有学生及其选课信息(包括没有选课的学生);
- 查询“形式语言与自动机”先修课的课程名称;
- 查询“形式语言与自动机”间接先修课课程名称;
- 查询先修课为编译原理的课程名称;
- 查询间接先修课为离散数学的课程名称;
- 查询所有没有先修课的课程名称;
- 查询所有没选修“形式语言与自动机”课程的学生姓名;
- 查询所有选修了“形式语言与自动机”但没选修其先修课的学生姓名;
- 查询选修课程总学分大于等于28的学生姓名及其选修课程总学分;
- 查询选修了3门以上课程且成绩都大于85分的学生学号与姓名;
- 查询恰好选修了3门课并且都及格的学生姓名;
- 查询人数多于6的学院名称及其学生人数;
- 查询平均成绩高于王兵的学生姓名;
- 查询所有选修了离散数学并且选修了编译原理课程的学生姓名;
- 查询软件学院离散数学课程平均分;
- 查询年龄与“软件学院”所有学生年龄都不相同学生姓名及其年龄和学院;
- 查询各学院选修同一门课人数大于4的学院、课程及选课人数;
- 查询仅仅选修了“高等数学”一门课程的学生姓名;(学号、姓名及所在学院名称)
- 查询平均学分积小于70分的学生姓名。
- 查询选修了“信息学院”开设全部课程的学生姓名。
- 查询选修了“杨佳伟”同学所选修的全部课程的学生姓名;
练习5 DDL练习
- 创建2张表,信息如下:
图书(编号,书名,作者,ISBN,出版社编号,版本,出版日期)。主码为编号,ISBN唯一。出版社编号为外 码,参照出版社表的编号。
出版社(编号,名称,地址,电话)。主码为编号。
要求:(1)创建表的同时创建约束;
(2)删除所创建的表;
(3)重新创建表,在表创建之后增加约束。
create table press(
pno text primary key,
pname text,
address text,
pn text
);
create table books(
bno text primary key,
bname text,
aname text,
isbn text unique,
pno text references press(pno),
ver text,
pdate date
);
drop table books;
drop table press;
--外键中发起引用的表先删,被引用的表后删
create table press(
pno text,
pname text,
address text,
pn text
);
create table books(
bno text,
bname text,
aname text,
isbn text,
pno text,
ver text,
pdate date
);
alter table press
add primary key(pno);
alter table books
add primary key(bno),
add unique(isbn),
add foreign key(pno) references press(pno);
- 分别向两张表中各插入2行数据。将其中一个出版社地址变更一下。删除所插入数据。
insert into press values('某出版社1','某出版社','某地','20001023'),
('某出版社2','某出版社','某地','20001023');
insert into books values('某编号1','某书','某人','某ISBN号1','某出版社1','某版本','2000-10-23'),
('某编号2','某书','某人','某ISBN号2','某出版社1','某版本','2000-10-23');
update press set address = '中国' where pno = '某出版社1';
delete from books;
delete from press;
- 创建一个软件学院所有选修了“离散数学”课程的学生视图,并通过视图插入一行数据。创建一个各门课程平均分视图。
对视图的更新可以唯一的转化为对于基本表的更新,那么更新是可以的
视图涉及聚集函数,那么更新一般是不被允许的
create view st as (select student.sname
from student,department,sc,course
where student.dno in (select dno
from department
where department.dname = '软件学院'
)
and
sc.sno = student.sno
and
sc.cno in (select cno
from course
where cname = '离散数学'
)
)
with check option;
insert into st values('刘铭帅');
这种更新即为非法的,为什么呢?因为我在这里给view加入了with check option的条件,这里view插入一个新的数据后,这个数据在表中的其他字段实际上是null,是不符合view的筛选条件的,所以不应该出现在view中。
运行结果:
这里按照题意就取消掉with check option了
create view avgs as (select course.cno,t1.avgg
from course left join (select sc.cno,avg(sc.score) as avgg
from sc
group by sc.cno
) t1
on
course.cno = t1.cno
);
- 创建一张学生平均成绩表s_score(sNo,sName,avgscore),并通过子查询插
在数据库中,向数据库中插入数据,使用insert into关键字。在数据库中插入数据有三种方法。
1)插入单个字段的情况
insert into table_name(列名) values(值);
2)插入多个字段的情况
2.1) 插入两个字段以上
insert into table_name(列名1,列名2,列名3,) values(值1,值2,值3);
2.2)插入全部所有字段
insert into table_name values(值1,值2,值3);//值要和表中的字段顺序类型一致
3)使用子查询向表中插入数据
insert into table_name 子查询select语句;//需要注意的是不能违反表table_name的约束条件,以及需要和table_name的字段一致,或者少于它,但是不能多于它。
create table s_score(sNo text unique not null,
sName text,
avgscore numeric(6,4)
);
insert into s_score (select student.sno,student.sname,t1.avgg
from student left join (select sc.sno,avg(sc.score) as avgg
from sc
group by sc.sno
) t1
on
t1.sno = student.sno
);
select * from s_score;
练习6 DCL
尝试将多条SQL语句组成一个事务执行,体验提交和回滚操作。
一个事务transaction由begin…commit包含的语句构成,回滚可以使用rollback语句。
标签:INSERT,PostgreSQL,INTO,VALUES,student,sc,null 来源: https://blog.csdn.net/weixin_42767528/article/details/118789497
本站声明: 1. iCode9 技术分享网(下文简称本站)提供的所有内容,仅供技术学习、探讨和分享; 2. 关于本站的所有留言、评论、转载及引用,纯属内容发起人的个人观点,与本站观点和立场无关; 3. 关于本站的所有言论和文字,纯属内容发起人的个人观点,与本站观点和立场无关; 4. 本站文章均是网友提供,不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属;如您发现该文章侵犯了您的权益,可联系我们第一时间进行删除; 5. 本站为非盈利性的个人网站,所有内容不会用来进行牟利,也不会利用任何形式的广告来间接获益,纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。