[Database] 17. rownum 변수 활용

set @rownum := 0;

select ename, sal, @rownum := @rownum+1
from
(
select ename, sal
from emp
order by sal desc
) nemp;

-- 참고 (변수를 from절에 초기화 하는법)
SELECT @num as num
from emp, (select @num:=50) t;

-- 참고 (변수를 만드는 법)
set @rownum := 0;
select empno, ename, sal, (@rownum := @rownum+1)
from emp;