어떤게 최신인지 알수 있는 기준은 뭔가요?? 궁금해서요..

SELECT *
  FROM (SELECT new_old_cap, r_code, new_new_cap, old_old_code, old_old_cap
             , ROW_NUMBER() OVER(ORDER BY 등록일자 DESC) rn
          FROM a_cap
         WHERE new_old_cap = 'SBS'
           AND new_new_cap = 'SBS2'
        )
 WHERE rn = 1
;