题解 | 有取消订单记录的司机平均评分

SELECT IFNULL(driver_id, "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 DATE_FORMAT(order_time, "%Y-%m")='2021-10' AND ISNULL(fare)
) AND NOT ISNULL(grade)
GROUP BY driver_id
WITH ROLLUP;