select  cs_code
    ,cs_pkkey
from    tbl_costs
where   (
        (cs_date >= convert(datetime,'20111205') and cs_dateend <= convert(datetime,'20111205'))
    or  (cs_date >= convert(datetime,'20111205') and cs_date <= convert(datetime,'20111205'))
    or  (cs_dateend <= convert(datetime,'20111205') and cs_dateend >= convert(datetime,'20111205'))
    or  (cs_date <= convert(datetime,'20111205') and cs_dateend >= convert(datetime,'20111205'))
        )
and     cs_pkkey = 3619
and     cs_prkey = 1051