1141.User Activity for the Past 30 Days I

* Problem

Write a solution to find the daily active user count for a period of 30 days ending 2019-07-27 inclusively. A user was active on someday if they made at least one activity on that day.

Return the result table in any order.

 

* Explanation

Note that we do not care about days with zero active users.

 

* Solution (Success)

# Write your MySQL query statement below
SELECT
  activity_date AS day,
  COUNT(DISTINCT user_id) AS active_users
FROM Activity
WHERE activity_date BETWEEN '2019-06-28' AND '2019-07-27'
GROUP BY 1;