-- Assume you're given a table containing information on Facebook user actions. Write a query to obtain number of monthly active users (MAUs) in July 2022, including the month in numerical format "1, 2, 3". -- Hint: -- An active user is defined as a user who has performed actions such as 'sign-in', 'like', or 'comment' in both the current month and the previous month. WITH cte AS ( SELECT user_id, EXTRACT(month FROM event_date) AS month, event_type FROM user_actions WHERE EXTRACT(month FROM event_date) IN (6, 7) AND event_type IN ('sign-in', 'like', 'comment') ) SELECT 7 AS month, COUNT(DISTINCT CASE WHEN month_count = 2 THEN user_id END) AS monthly_active_users FROM ( SELECT user_id, COUNT(DISTINCT month) AS month_count FROM cte GROUP BY 1 ) x -- my approach: WITH cte AS ( SELECT *, EXTRACT(month FROM event_date) AS current FROM user_actions ) SELECT * FROM cte WHERE event_type IN ('sign-in', 'like', 'comment') AND current IN ('7','6') -- remarks : not that tough, but couldn't figure out how to proceed.