Suppose that Spotify would like to understand better the average listening duration for each genre of music on their platform. **Write a SQL query that calculates the average listening duration per genre for every month.** Assume you have access to a user_activity table and a songs table with the following schema: user_activity **Example Input:** activity_id user_id song_id timestamp listening_duration_sec ------------------------------------------------------------------- 1 101 5001 2022-03-01 09:00:00 210 2 102 6985 2022-03-01 11:30:00 120 3 103 5001 2022-03-01 15:45:00 300 4 101 6985 2022-04-01 08:45:00 180 5 102 5001 2022-04-01 10:00:00 240 songs **Example Input:** song_id genre ---------------- 5001 Rock 6985 Pop Your aim is to produce a table like: **Example Output:** mth genre avg_listening_duration_sec ----------------------------------------- 3 Rock 255 3 Pop 120 4 Rock 240 4 Pop 180 **Answer:** SELECT EXTRACT(MONTH FROM timestamp) AS month, genre, AVG(listening_duration_sec) AS avg_listening_duration_sec FROM user_activity ua JOIN songs s USING(song_id) GROUP BY 1, 2 ---