mysql之DML的select分组排序方式

create table department(
-> depart_id int primary key auto_increment comment '部门编号',
-> depart_name varchar(50) not null comment '部门名称'
-> ) auto_increment=1001;

create table employee( n for the right syntax to use near 'redsodsnvjnv' at line 1
-> emp_num int primary key auto_increment comment '员工编号',
-> emp_name varchar(30) not null comment '员工姓名',
-> emp_job varchar(30) not null comment '员工岗位',
-> hire_data datetime not null comment '入职时间',
-> salary int not null comment '薪资',
-> bonus int not null comment '奖金',
-> dept_id int comment '部门编号'
-> );

alter table employee add constraint emp_dept_fk foreign key(dept_id) references department(depart_id);

insert into department values(null,'科技部门'),(null,'法律部门'),(null,'后勤部门'),(null,'财务部门');

insert into employee values((null,'张三','工程师','2023.9.1',12000,1000,1001),(null,'张四','工程师','2023.9.1',11000,1010,1001),(null,'李三','会计','2023.9.1',5000,300,1004),(null,'张六','保安','2023.9.1',5000,500,1003),(null,'刘律','律师','2023.9.1',1000,1,1002);

delete from employee where emp_name='那个';

select dept_id,avg(salary) from employee group by dept_id;

select dept_id, avg((salary+bonus)*12) from employee group by dept_id;

select dept_id,max(salary) from employee group by dept_id;

select dept_id,min(salary) from employee group by dept_id;

select dept_id,sum(salary) from employee group by dept_id;

select dept_id,count(*) from employee group by dept_id;

select dept_ip,count(emp_name) from employee group by dept_id;

select emp_name,dept_id from employee order by dept_id;

select dept_id,emp_job,sum(salary) from employee group by dept_id, emp_job;

select dept_id,emp_job,sum(salary) from employee group by dept_id,emp_job having sum(salary>1000);

select * from employee limit 0,3;

select * from employee limit 2,7;