Mysql 查询指令 1

 一、查询两个时间字段相减的差值
 >>> (TIME_TO_SEC(时间字段一) - TIME_TO_SEC(时间字段二))
 select bl_no,
        task_result,
        carrier_code,
        task_start_time,
        return_data_time,
        receive_task_time,
        task_finish_time,
        (TIME_TO_SEC(task_finish_time) - TIME_TO_SEC(receive_task_time)) sec
 from lc_tracking_task_record
 order by task_finish_time desc;

1 二、时间格式化函数
2 >>> date_format(task_finish_time, '%Y-%m-%d %H:%i')
3 select s.carrier_code,count(*),s.t1
4 from (
5        select *, date_format(receive_task_time, '%Y-%m-%d %H:%i') t1,date_format(task_finish_time, '%Y-%m-%d %H:%i') t2
6        from lc_tracking_task_record) s
7 where s.t1 = s.t2
8 group by s.t1,s.carrier_code
9 order by count(*) desc