分组取出最小时间记录

Question

要求取出时间字段最小的值。结果是：
+---------+-----------------+-------------------+------+--------------+--------------------+-------------------+
| id      | imei            | mac               | cid  | cpid         | package_name       | first_access_time |
+---------+-----------------+-------------------+------+--------------+--------------------+-------------------+
| 2683078 | 358848041736737 | 04:46:65:73:51:FE |  821 | 安卓市场     | com.mappn.pad.gfan |        1313732834 |
| 2686496 | 358848041736737 | null              |  821 | 安卓市场     | com.mappn.pad.gfan |        1313743980 |
+---------+-----------------+-------------------+------+--------------+--------------------+-------------------+谢谢

Answer 1

select *  from table order by first_access_time desc  limit 1

Answer 2

参考下贴中的多种方法http://blog.csdn.net/acmain_chm/article/details/4126306
[征集]分组取最大N条记录方法征集，及散分....

Answer 3

select *
from tb A
where not exits (select 1 from tb where mac=A.mac and A.first_access_time>first_access_time )

Answer 4

select * from tt A
 where not exits (select 1 from tt where a.mac=mac and A.first_access_time>first_access_time )