2021年国庆在北京接单3次及以上的司机统计信息

明确题意：

统计2021年国庆7天期间在北京市接单至少3次的司机的平均接单数和平均兼职收入（暂不考虑平台佣金，直接计算完成的订单费用总额），结果保留3位小数。

问题分解：

• 计算2021国庆在北京接单至少3次的司机信息：
  • 关联接单表和打车记录表：tb_get_car_order JOIN tb_get_car_record USING(order_id)
  • 筛选北京国庆期间的记录：WHERE city = "北京" and DATE_FORMAT(order_time,"%Y%m%d") BETWEEN '20211001' AND '20211007'
  • 按司机ID分组：GROUP BY driver_id
  • 统计每个司机的接单量和接单收入：COUNT(order_id) as order_num, SUM(fare) as income
  • 筛选接单至少3次的分组（司机）：HAVING COUNT(order_id) >= 3
• 基于上述结果，统计他们的平均接单量和平均收入：
  • 平均接单量：AVG(order_num) as avg_order_num
  • 平均收入：AVG(income) as avg_income
• 保留3位小数：ROUND(x, 3)

细节问题：

• 表头重命名：as

完整代码：

SELECT "北京" as city, ROUND(AVG(order_num), 3) as avg_order_num,
    ROUND(AVG(income), 3) as avg_income
FROM (
    SELECT driver_id, COUNT(order_id) as order_num, SUM(fare) as income
    FROM tb_get_car_order
    JOIN tb_get_car_record USING(order_id)
    WHERE city = "北京" and DATE_FORMAT(order_time,"%Y%m%d") BETWEEN '20211001' AND '20211007'
    GROUP BY driver_id
    HAVING COUNT(order_id) >= 3
) as t_driver_info;