SQL：在最短的300次旅行中，这些骑手中有多少个是孩子

Question

[栏：trip_times，骑手：男性，女性，空者，孩子

SELECT trip_times, riders
FROM Table
ORDER BY trip_times ASC LIMIT 300 

最短的300次旅行中有多少儿童骑手？

Answer 1

SELECT SUM(IF(is_kid,1,0)) FROM (
    SELECT is_kid, trip_times, riders
    FROM Table
    ORDER BY trip_times ASC LIMIT 300 
) short_rides;

Answer 2

WITH SHORT_TRIPS AS (
SELECT trip_times, riders
FROM Table
ORDER BY trip_times ASC LIMIT 300
)

SELECT COUNT(*)
FROM SHORT_TRIPS
WHERE riders = 'kids'