题目一:使用连接查询的方式,查询出各员工所在部门的人数与工程数,工程数命名为count_project。(连接3个表,并使用COUNT内置函数)
Create table employee(
Id int(3)primary key,
Name varchar(20),
Age int(1)
);
Create table department(
Rearch int(3),
Constraint foreign key(Rearch) references employee(id),
Sale int(3),
Constraint foreign key(Sale) references employee(id)
);
Create table project(
pid int(3),
Constraint foreign key(pid) references employee(id),
Number int(1)default 0
);
Empoyee
Id(primary key) |
Name |
age |
001 |
Tom |
25 |
002 |
Jack |
18 |
003 |
Lucy |
33 |
111 |
Marry |
15 |
110 |
James |
21 |
Department
Rearch(foreign key) |
Sale(foreign key) |
001 |
111 |
002 |
110 |
003 |
|
Project
PId(foreign key) |
001 |
002 |
003 |
111 |
110 |
number(default 0) |
2 |
3 |
1 |
0 |
5 |
insert into project(pid,number)values(001,2),(002,3),(003,1),(111,0),(110,5);
只能分俩步完成
第一步:select id,name,age,count(rearch),numberfrom employee,department,project where id in(select rearch from departmentwhere rearch=employee.id ) and id in(pid) group by id;
第二步:select id,name,age,count(sale),numberfrom employee,department,project where id in(select sale from department wheresale=employee.id ) and id in(pid) group by id
题目二:
在挑战实验1中构建的成绩管理系统中,物理老师想要找出分数最高的同学进行表扬,请你找出这个同学并把他的信息(id、姓名、性别)输出到路径 E盘 下的physics.txt文件中。同时 Tom 的化学成绩有异议,需要在原来的基础上加3分,请更新 Tom 的化学成绩。
导入导出操作在可视化软件进行