CREATE DATABASE ems CHARACTER SET utf8mb4;
USE ems;
CREATE TABLE emp(
empno   INT PRIMARY KEY,
ename   VARCHAR(20) UNIQUE NOT NULL,
job     VARCHAR(20) NOT NULL,
mgr     INT ,
sal     DECIMAL(7,2),
comm    DECIMAL(7,2),
deptno  INT  
) ;
INSERT INTO emp 
VALUES
(9839,'刘一','董事长',NULL,6000,NULL,10),
(9982,'陈二','经理',9839,3450,NULL,10),
(9369,'张三','保洁',9902,900,NULL,20),
(9566,'李四','经理',9839,3995,NULL,20),
(9988,'王五','分析员',9566,4000,NULL,20),
(9902,'赵六','分析员',9566,4000,NULL,20),
(9499,'孙七','销售',9698,2600,300,30),
(9521,'周八','销售',9698,2250,500,30),
(9654,'吴九','销售',9698,2250,1400,30),
(9844,'郑十','销售',9698,2500,0,30),
(9900,'萧十一','保洁',9698,1050,NULL,30);
SELECT empno,ename,job,mgr,sal,comm,deptno FROM emp;
SELECT empno,job,mgr,sal,comm,deptno,ename FROM emp;
SELECT * from emp;