쿼리문 작성 및 해석 권장 순서(절대 실행 순서 아님)

SQL> select deptno, sum(sal) "집계"    -- 4 (Mandatory)
         from emp                                   -- 1 (Mandatory)
         where sal >= 1000                      -- 2
         group by deptno                        -- 3
         having sum(sal) >= 8500            -- 5
         order by deptno;                       -- 6