leetcode 1141 查詢進30天活躍用戶數

leetcode 1141 查詢進30天活躍用戶數

select activity_date as day , count(distinct user_id) as active_users  
from Activity a
where activity_date between DATE_SUB('2019-07-27',INTERVAL 29 DAY) and '2019-07-27'
group by activity_date

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