oracle 12c top-n query

1. Top-N query

  -- order 순으로 5개 row를 가지고 옴

  SELECT employee_id, last_name

  FROM hr.employees

  ORDER BY employee_id

  FETCH FIRST 5 ROWS ONLY;

  -- 그 다음 5개 row를 가지고 올때

   SELECT employee_id, last_name

   FROM hr.employees

   ORDER BY employee_id

   OFFSET 5 ROWS FETCH NEXT 5 ROWS ONLY;

 -- order by 순으로 동일 순서인 모두 row 표시

   SELECT employee_id, last_name

   FROM hr.employees

   ORDER BY employee_id

   FETCH FIRST 5 PERCENT ROWS WITH TIES;