Select Qry.*, Case When Qry.Door = '' Then Qry.Door Else Substring(Qry.Door, 3, Len(Qry.Door) - 2) End As Door
From (SELECT dbo.tblHardware.Cmp_Id, Hardware_Id , Hardware_Code AS
[Hardware Code],
(Select ', ' + cast(Door_Name as varchar) FROM tbldoor
WHERE
tbldoor.Hardware_Id =
tblHardware.Hardware_Id FOR XML path('')) Door
FROM dbo.tblHardware
WHERE (dbo.tblHardware.Is_Deleted
= 0)) As Qry
Pleases refer below site for more detail
http://blog.sqlauthority.com/2009/11/25/sql-server-comma-separated-values-csv-from-table-column/