比如有个表table
id col datetime
1 aa 2012-01-01
2 aa 2012-01-03
3 bb 2012-03-01
4 cc 2011-10-12
5 bb 2013-11-11
我要得到
2 aa 2012-01-03
5 bb 2013-11-11
4 cc 2011-10-12
就是col字段相同的，只取datetime最后的那一条记录~~拜托了~~
------解决方案--------------------
- SQL code
select *from tb twhere not exists (select 1 from tb where col=t.col and date>t.date)