[SQL문제풀기] Ranking Most Active Guests

문제

StrataScratch - Ranking Most Active Guests

StrataScratch

https://platform.stratascratch.com/coding/10159-ranking-most-active-guests?code_type=3

내가 작성한 정답

MySQL, PostgreSQL, Oracle

select id_guest, dense_rank() over(order by sum(n_messages) desc) ranking, sum(n_messages) sum_n_messages
from airbnb_contacts
group by id_guest
order by 2;