ISNULL((
SELECT
    COUNT(h.[idhelpdesk])
from [object] o
INNER JOIN [helpdesk] h ON h.[object] = o.[idobject]
INNER JOIN [string] sStatus ON sStatus.[idstring] = h.[statuscolor]
WHERE
    o.[idobject] = [object].[idobject]
    AND o.[status] = 0
    AND sStatus.[key] IN ('new', 'ongoing', 'delayed', 'parked')
), 0)