SQL - value for the last date -

sounds easy guess of guys can't find solution due poor sql knowledge.

i have request:

• first 3 columns margin can null

i want create column last application margin rule:

• if margin null last value no null find.

screenshot here:

thanks lot

use isnull/coalesce , subquery:

select scope_enum_compete, margin, date_test,        isnull(margin, ( select top 1 margin                         dbo.tablename t2                         margin not null                          ,  t2.date_test < t1.date_test                          order date_test desc ))  [last applicable margin] dbo.tablename t1