题解 | 统计快递运输时长

WITH exp_type AS(
    SELECT 
        exp_number,
        exp_type
    FROM express_tb
) --选取express的type
SELECT
    b.exp_type,
    ROUND(avg(TIMESTAMPDIFF(MINUTE,a.out_time,a.in_time)/60),1) AS time
FROM exp_action_tb AS a
LEFT JOIN exp_type AS b
ON a.exp_number=b.exp_number
GROUP BY b.exp_type
ORDER BY avg(TIMESTAMPDIFF(HOUR,a.out_time,a.in_time)) ASC;