Mysql 查询指令 1

 1 一、查询两个时间字段相减的差值
 2 >>> (TIME_TO_SEC(时间字段一) - TIME_TO_SEC(时间字段二))
 3 select bl_no,
 4        task_result,
 5        carrier_code,
 6        task_start_time,
 7        return_data_time,
 8        receive_task_time,
 9        task_finish_time,
10        (TIME_TO_SEC(task_finish_time) - TIME_TO_SEC(receive_task_time)) sec
11 from lc_tracking_task_record
12 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