SELECT [radnik] as Radnik,
SUM (cast((CASE WHEN DATEPART(WEEKDAY, vrijemeprijave) in (1,7) then 0 else (CASE WHEN (DATEDIFF(SECOND, vrijemeprijave, vrijemeodjave) / 3600) > 8 THEN 8 ELSE(DATEDIFF(SECOND, vrijemeprijave, vrijemeodjave) / 3600) END) end)as float)) AS 'Radni sati',
SUM (cast((CASE WHEN DATEPART(WEEKDAY, vrijemeodjave) in (1,7) then (DATEDIFF(SECOND, vrijemeprijave, vrijemeodjave) / 3600) else(case when(DATEDIFF(SECOND, vrijemeprijave, vrijemeodjave) / 3600) > 8 then ((DATEDIFF(SECOND, vrijemeprijave, vrijemeodjave) / 3600)-8) ELSE NULL END) end)as float)) AS 'Prekovremeni'
from [prijava_radnika]
group by [radnik]
Solved...thank you all people...