MySQL语句练习

--create database company
create database company;
use company;

create table dept
(
deptno int(3) primary key,
dname varchar(14),
loc varchar(13)
);

create table emp(

empno int(4) not null primary key,
ename varchar(10),
job varchar(10),
mgr int(4),

hiredate datetime,
sal double,
comm double,
deptno int(3),

foreign key(deptno) references dept(deptno)
);

create table salgrade(

grade int(3) primary key,
losal int(3),
hisal int(3)
);

先求出emp表中最高薪水以下的所有薪水值
select distincte1.sal from emp e1 join emp e2 on(e1.sal<e2.sal);