check this...

select *

from (select row_number() over(partition by memno, date_trans

order by id desc) my_rowid,

id, memno, date_trans

from<tablename> ) a

wheremy_rowid = 1

Dudes, Check the following link. I wasted lot of time but finally found a great great solution...

http://www.tek-tips.com/viewthread.cfm?qid=1247725&page=1

Great work Dan