[SQL문제풀기] 업그레이드 된 아이템 구하기

문제

내가 작성한 정답

SELECT I.ITEM_ID,I.ITEM_NAME,I.RARITY
FROM ITEM_TREE T
LEFT JOIN ITEM_INFO I ON T.ITEM_ID = I.ITEM_ID
WHERE PARENT_ITEM_ID IN (SELECT ITEM_ID
                           FROM ITEM_INFO 
                          WHERE RARITY = 'RARE')
ORDER BY I.ITEM_ID DESC;

다른 사람들이 작성한 정답

SELECT I.ITEM_ID, I.ITEM_NAME, I.RARITY
FROM 
ITEM_INFO I JOIN ITEM_TREE T 
ON I.ITEM_ID = T.ITEM_ID
WHERE T.PARENT_ITEM_ID IN ((SELECT S.ITEM_ID 
                            FROM ITEM_INFO S
                            WHERE RARITY = 'RARE'))
ORDER BY ITEM_ID DESC