oracle 树状查讯问题

select * from
(select level,menu_id,parent_id,menu_name
 from menu
conncet by menu_id = parent_id
start with menu_id = 1
 )
 where level = 2

 

为什么还提示 此查询块中需要connect by 语句？有哪位大侠帮着解决下