WITH CTE AS

(

SELECT DISTINCT

Category

FROM Sampletable

)

SELECT Category,

Organisams = STUFF((

SELECT ',' + Organisams

FROM Sampletable

WHERE Category = CTE.Category

ORDER BY Organisams

FOR XML PATH(''),

TYPE).value('.','varchar(max)'),1,1,'')

FROM CTE

ORDER BY Category;

There is an article related to this method below

http://www.sqlservercentral.com/articles/comma+separated+list/71700/