题解|晕晕 #有取消订单记录的司机平均评分#

# SELECT DISTINCT driver_id
# FROM tb_get_car_order
# WHERE start_time IS NULL

(SELECT driver_id,ROUND(AVG(grade),1) AS avg_grade
FROM tb_get_car_order
WHERE driver_id IN(
    SELECT driver_id
    FROM tb_get_car_order
    WHERE start_time IS NULL
)
GROUP BY driver_id
ORDER BY driver_id)
UNION
(SELECT '总体' AS driver_id,ROUND(AVG(grade),1) AS avg_grade
FROM tb_get_car_order
WHERE driver_id IN(
    SELECT driver_id
    FROM tb_get_car_order
    WHERE start_time IS NULL
))

怎么就过啦？哈哈哈哈哈哈