-- [PREPARED_DATA]
		SELECT
			n.id AS grpid,
			n.title AS grptitle,
			-- FLag, ob eine neue ID beginnt
			@flag := (@last_id <> n.id)	AS flag,
			-- Counter pro ID setzen. Wird für die Sortierreihenfolge im GROUP_CONCAT() verwendet
			CASE 
				WHEN @flag
				THEN @cnt := 1
				ELSE @cnt := @cnt+1
			END AS cnt,
			-- Parent ID ermitteln
			CAST(CASE 
				WHEN @flag
				THEN @pid := n.id
				ELSE @pid := @npid
			END AS SIGNED) AS pid,
			-- Nächste Parent ID Ermitteln
			(
				SELECT @npid := n2.parentid
				FROM nav n2  
				WHERE n2.id = @pid
			)					AS npid,			
			@last_id := n.id AS nid
		FROM
			(SELECT @last_id := 0, @pid := 0, @npid := NULL, @cnt:=0) AS vars,
			(SELECT n3.id FROM nav n3) AS loop_rows,
			(SELECT n4.id, n4.title, n4.parentid FROM nav n4) AS n