Question : SQL selection

I have a table, example below

PK     M_ID            Arrival_Date    Dept
01     1             01/06/08          P1234
02     1             01/05/08          Q1232
03     3             02/04/09          P1234
04     4             01/05/08          K9999
05     4             01/05/09          Kqwew

I would like to pick of the most current Dept code for each M_ID. As you can see there can be multiple entries for each M_ID so I am not sure how to do this.

The results I am after should be something like:

PK     M_ID            Arrival_Date    Dept
01     1             01/06/08          P1234
03     3             02/04/09          P1234
05     4             01/05/09          Kqwew

can anybody help?

Answer : SQL selection

select a.pk,a.m_id,a.arrival_date,a.dept
from YourTable a
join (select m_id,max(arrival_date) mx_arrival_date from yourtable group by m_id) b
on a.m_id=b.m_id
and a.arrival_date = mx_arrival_date.mx_arrival_date