c# - 时间和 DISTINCT 列之间的 sql 查询

Question

我的车辆表格看起来像

vehNo   tTime                     odo     
ABC     2013-02-13 10:30:00       80       
ABC     2013-02-12 10:30:00       10      
ABC     2013-02-12 12:30:00       30      
ABC     2013-02-13 01:30:00       40      
ABC     2013-02-13 02:30:00       40 
ABC     2013-02-13 03:30:00       40 
XYZ     2013-02-13 03:33:00       44
ABC     2013-02-13 04:30:00       60 
ABC     2013-02-13 11:30:00       100 

我可以在 2013-02-12 10:30:00 和 2013-02-13 10:30:00 之间给出(按时间排序)但是我如何得到 DISTINCT odo 就像

ABC     2013-02-12 10:30:00       10 
ABC     2013-02-12 12:30:00       30 
ABC     2013-02-13 03:30:00       40         (time being latest, ignoring 1:30 & 2:30)
ABC     2013-02-13 04:30:00       60
ABC     2013-02-13 10:30:00       80 

我在 MSSql server 2005 上运行

Answer 1

select vehNo, max(tTime) as [tTime], odo
from vehicles
group by vehNo, odo
order by vehNo, odo

显然，对于“2013-02-12 10:30:00 和 2013-02-13 10:30:00”之间，您可以在中间添加一个 where 子句:

select vehNo, max(tTime) as [tTime], odo
from vehicles
where tTime between @start and @end
group by vehNo, odo
order by vehNo, odo