1661-Average-Time-Of-Process-Per-Machine.sql

-- 1661-Average-Time-Of-Process-Per-Machine
-- Exercise from: https://leetcode.com/problems/average-time-of-process-per-machine/
SELECT
    s.machine_id,
    ROUND(
        AVG(e.timestamp - s.timestamp),
        3
    ) AS processing_time
FROM
    Activity s
    JOIN Activity e ON s.machine_id = e.machine_id
    AND s.process_id = e.process_id
WHERE
    s.activity_type = "start"
    AND e.activity_type = "end"
GROUP BY
    s.machine_id