문제 link
https://www.hackerrank.com/challenges/harry-potter-and-wands/problem
Code link
https://github.com/JamesJung01/Hackerrank_sql/blob/main/02_Medium/Ollivander's_Inventory.sql
SELECT w.id, wp.age, w.coins_needed, w.power FROM wands as w JOIN wands_property as wp ON w.code = wp.code WHERE wp.is_evil = 0 AND w.coins_needed = (SELECT min(coins_needed) FROM wands AS w1 JOIN wands_property AS wp1 ON w1.code = wp1.code WHERE w1.power = w.power AND wp1.age = wp.age) ORDER BY w.power DESC, wp.age DESC;