How to create a view with effective date

 Hi,

Would anybody know how to create a view in database that allow user to retrieve by effective date. Thx.

Table "Schedule":

loan_no  (key)         effective_dt (key)     opb

1234567                  2009/04/10      1123456.57

1234567                  2009/03/10     2123456.57

1234567                  2009/02/10     3123456.57

select opb from "view"

where  loan_no = '1234567'

and      effective_dt <= '2009/03/12' (date input by user)

that returns row:

1234567                  2009/03/10     2123456.57