문제문제 : https://leetcode.com/problems/average-selling-price/description/?envType=study-plan-v2&envId=top-sql-50 테이블 : Prices+---------------+---------+| Column Name | Type |+---------------+---------+| product_id | int || start_date | date || end_date | date || price | int |+---------------+---------+(product_id, start_date, end_date)는 테이블의 PK이다.테이블의 각 행은 sta..