WITH a AS( SELECT city, event_time AS uv_time, 1 AS uv_cnt FROM tb_get_car_record UNION ALL SELECT city, end_time AS uv_time, -1 AS uv_cnt FROM tb_get_car_record WHERE order_id IS NULL UNION ALL SELECT city, IFNULL(start_time, finish_time) AS uv_time, -1 AS uv_cnt FROM tb_get_car_order JOIN tb_get_c...