[lv2] 업그레이드 된 아이템 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/273711

 

문제 해석이 살짝 난해했다

SELECT ITEM_ID,	ITEM_NAME, RARITY
FROM ITEM_INFO JOIN ITEM_TREE
USING(ITEM_ID)
WHERE PARENT_ITEM_ID IN (SELECT ITEM_ID
                        FROM ITEM_INFO
                        WHERE RARITY = 'RARE')
ORDER BY ITEM_ID DESC