mysql 随堂练习

Posted 11-21

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create database a;
use a;

create table employee(
empid varchar(10) primary key not null,
name varchar(10),
gender varchar(10),
title varchar(20),
birthday date,
depid varchar(10));

create table department(
depid varchar(10) primary key not null,
depname varchar(20));

create table salary(
empid varchar(10) primary key not null,
base_salary decimal(8,2),
title_salary decimal(8,2),
deduction int);

 

#修改表结构,在部门表中添加一个”部门简介”字段

alter table employee add 部门简介 varchar(100);

 

insert into employee values(1001,张三,,高级工程师,1980-01-01,1111,null);
insert into employee values(1002,李四,,助理工程师,1980-11-01,1111,null);
insert into employee values(1003,王五,,工程师,1980-01-21,2222,null);
insert into employee values(1004,赵六,,工程师,1980-01-11,2222,null);

insert into department(depid,depname) values
(1111,生产部),
(2222,销售部),
(3333,人事部);

insert into salary values
(1001,3200,1200,200),
(1002,4200,1100,100),
(1003,5200,2200,200),
(1004,2000,1500,150);

 

#5将李四的职称改为“工程师”,并将她的基本工资改为5700元,职务工资为1600。

update employee set title="工程师" where name="李四";

update salary set base_salary=5700,title_salary=600 
where empid=(select empid from employee where name="李四");

 


#6查询出每个雇员的雇员编号,姓名,职称,所在部门,实发工资和应发工资。
#涉及employee表和salary表、department表

select employee.empid,name,title,depname,(base_salary+title_salary-deduction) as 实发工资,
(base_salary+title_salary) as 应发工资 from employee 
left join salary on employee.empid=salary.empid
left join department on department.depid=employee.depid;

 


#7查询姓“张”且年龄小于40岁的员工的记录。

select * from employee where name like"张%" and (year(curdate())-year(birthday))<40;

 

 

#8查询销售部所有雇员的雇员编号,姓名,职称,部门名称,实发工资。
#涉及employee表和salary表、department表

select employee.empid,name,title,depname,
(base_salary+title_salary-deduction) as 实发工资 from employee 
left join salary on employee.empid=salary.empid
left join department on department.depid=employee.depid where depname="销售部";

 

 


#9统计出各类职称的人数。
#按职称分组

select title,count(*)as 人数 from employee group by title;

 

 


#10.统计各部门的部门名称,实发工资总和,平均工资。
#涉及三张表及group by分组

select depname,sum(base_salary+title_salary-deduction)as 实发工资,
avg(base_salary+title_salary-deduction) as 平均工资 from employee 
left join salary on employee.empid=salary.empid
left join department on department.depid=employee.depid group by depname;

 

 

select * from employee;
select * from salary;
select * from department;

 

 

 

 

 

 

 

 

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