oracle查詢遞歸表節點

​

select * from (
select t.*,rownum rn from  (
select a.*,b.name as classname from T_DBSET a 
left join t_dbclass b 
on a.classid=b.id   
where  a.classId in(
select id from t_dbclass 
start with id = 'fddbfb7b898544aab4dd9840b8cc46bc' 
connect by prior id = fartherid
)  
) t
) 
where rn >0 and rn<=30