标签：employee HERE 分组 varchar alt pre arch from value
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‘,‘男‘,‘高级工程师‘,‘1980-01-01‘,‘1111‘,null); insert into employee values(‘1002‘,‘李四‘,‘女‘,‘助理工程师‘,‘1980-11-01‘,‘1111‘,null); insert into employee values(‘1003‘,‘王五‘,‘男‘,‘工程师‘,‘1980-01-21‘,‘2222‘,null); insert into employee values(‘1004‘,‘赵六‘,‘男‘,‘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;
标签：employee HERE 分组 varchar alt pre arch from value
原文地址：https://www.cnblogs.com/Koi504330/p/11901736.html
