select empno as 사원번호, ename as 사원이름, sal as "Salary"
from emp;
as
--> 생략가능""
) 활용select ename 사원이름, sal 월급, comm 커미션
from emp;
create table emp21
( empno number(10),
ename varchar2(20),
age number(10),
birth date,
telecom varchar2(10),
major varchar2(50),
email varchar2(60),
address varchar2(100) ) ;