
()안에 아무것도 안쓰면 전체를 뜻함
select deptno, job, sum(sal)
from emp
group by grouping sets( (deptno), (job), () );
select job, sum(sal)
from emp
group by grouping sets((job), ()); -- job에 괄호 안써도 됨

select job, sum(sal)
from emp
group by grouping sets(job,())
order by job asc nulls first;
select deptno, job, sum(sal)
from emp
group by grouping sets((deptno,job), (deptno), () )
order by deptno asc;

사원번호, 이름, 월급을 출력하는데 다음과 같이 맨 아래쪽에 전체 토탈월급을 출력하시오

select empno, ename, sum(sal)
from emp
group by grouping sets((empno,ename), ());