-- 创建EMP表

CREATE TABLE EMP

(

EMPNO int(4) PRIMARY KEY,

ENAME VARCHAR(10),

JOB VARCHAR(9),

MGR INT(4),

HIREDATE DATE,

SAL DOUBLE(7,2),

COMM DOUBLE(7,2),

DEPTNO INT(2)

);

-- where查询 语句

SELECT * from emp;

SELECT * FROM DEPT;

SELECT * FROM SALGRADE;

-- where 条件查询

-- 查询员工编号为7000的所有信息

select * from emp where empno=7000;

-- 分别查询薪资大于，小于，不等于1000元员工所有信息

select * from emp where sal>=1000;

select * from emp where sal<=1000;

select * from emp where sal!=1000;

-- <>代表不等于

select * from emp where sal<>1000;

-- 查询入职日期大于1981年的员工信息

select * from emp where HIREDATE>"1981";

SELECT * from emp;

-- and运算符

-- 查询薪资大于1000，并且小于1500元员工的所有信息

select * from emp where sal>=1000 and sal<1500;

select * from emp where sal>=1000 && sal<1500;

-- [500,1600]BETWEEN AND

select * from emp where sal BETWEEN 500 and 1600;

-- 不在该区间信息

select * from emp where sal not BETWEEN 1000 and 1500;

-- or运算符

-- 查询信息小于1500或者大于3000的员工

select * from emp where sal<1000 or sal >1200;

select * from emp where sal<1000 || sal >1200;

-- in,or 查找具体值是否在某范围里

select * from emp where sal in(500,800,300);

SELECT * from emp where sal=500 or sal=300 or sal=800;

-- not in 查找具体值是否在某范围里

select * from emp where sal not in(500,800,300);