SUM mit DATEDIFF

[Jumpy]

Was passiert, wenn man die Summe mal anders bildet?

SQL-Code:

Select Sum(Wert) From
(

SELECT
       CAST(
            DATEDIFF(hh,
                     (R.von + CAST(R.wert2 AS time)),
                     (R.bis + CAST(R.wert3 AS time))
                    )
            AS int
           ) as Wert
FROM auplan R 

)