[SQL문제풀기] Apple Product Counts

문제

StrataScratch - Apple Product Counts

StrataScratch

https://platform.stratascratch.com/coding/10141-apple-product-counts?code_type=1

내가 작성한 정답

MySQL, PostgreSQL, Oracle

select u.language, 
        count(distinct case when e.device in ('macbook pro','iphone 5s','ipad air') then e.user_id end) n_apple_user,
        count(distinct u.user_id) n_total_users
from playbook_events e
join playbook_users u
on e.user_id = u.user_id 
group by u.language
order by 3 desc;