Pivot Query
use below query to get result
select sid, isnull(sum([1]),0) as Reason1,isnull(sum([2]),0) as Reason2,isnull(sum([3]),0) as Reason3 from
(
SELECT sid, [1], [2] , [3]
FROM
(
select id,sid,datediff(d,Startdate,enddate) as diff,Reason from TBLNM
) up
PIVOT (SUM(diff) FOR Reason IN ([1], [2],[3])) AS pvt
)
as t group by sid
Happy Coding!
:)