[SQL] 해커랭크 Ollivander's Inventory

SELECT C.ID, B.AGE, A.MIN_COINS_NEEDED, A.POWER
  FROM (SELECT CODE, MIN(COINS_NEEDED) AS MIN_COINS_NEEDED, POWER FROM WANDS GROUP BY CODE, POWER) A
     , WANDS_PROPERTY B
     , WANDS C
 WHERE A.CODE = B.CODE
   AND A.CODE = C.CODE
   AND A.MIN_COINS_NEEDED = C.COINS_NEEDED
   AND A.POWER = C.POWER
   AND B.IS_EVIL = 0
 ORDER BY A.POWER DESC, B.AGE DESC

해커랭크 Ollivander's Inventory SQL