Restaurant Growth.md

⚙문제보기

🔎문제 풀이 MySQL

SELECT a.visited_on AS visited_on, SUM(b.day_sum) AS amount,
       ROUND(AVG(b.day_sum), 2) AS average_amount
FROM
  (SELECT visited_on, SUM(amount) AS day_sum FROM Customer GROUP BY visited_on ) a,
  (SELECT visited_on, SUM(amount) AS day_sum FROM Customer GROUP BY visited_on ) b
WHERE DATEDIFF(a.visited_on, b.visited_on) BETWEEN 0 AND 6
GROUP BY a.visited_on
HAVING COUNT(b.visited_on) = 7;

---

어려워서 참고함