--DECLARE @startDate DATETIME = '2015-08-10' --DECLARE @endDate DATETIME = '2015-08-30' SELECT effectedObject_id AS 'Objekt-ID', effectedObject_id2 AS 'Status-ID', descUserCn AS 'Kennung', CONVERT(VARCHAR, timestamp, 104) + ' ' + CONVERT(VARCHAR, timestamp, 108) AS 'Timestamp' --, description FROM tblActionLog JOIN v_Users ON v_Users.intUserCn = tblActionLog.effectedObjectInt_id WHERE action_id = 128 AND descUserCn LIKE 'p%' AND (@startDate IS NULL OR @startDate <= timestamp) AND (@endDate IS NULL OR timestamp <= @endDate) ORDER BY tblActionLog.timestamp