问各位大侠一个数据库查询问题？

[bucce]

现有表A,表B;表结构如下显示：
-----------------------------------------
表A结构
-----------------------------------------
aID varchar(32) not null PRIMARY KEY
aname varchar(32) not null
bID varchar(32) not null
-----------------------------------------
！！！！！！！！！！！！！！！！！！！！！
-----------------------------------------
表B结构
-----------------------------------------
bID varchar(32) not null PRIMARY KEY
b_parentID varchar(32) not null /*说明对应表B里的bID,可以看成与bID有父子关系*/
bname varchar(32) not null
-----------------------------------------
问题如下：
要根据表A的aID查找出所有B表中的bID()注意：bID是找到所有与他有关的b_parentID记录

[zhangwonderful]

select a.*
from 表B a left join 表B b
on a.b_parentID=b.bID
where exists (select from 表A c where c.bID=a.bID)

[crazylaa]

select bid from b start with id=(select bid from a where a.aid='?????') connect by prior b_parentID=bid

[小灰狼W]

查子节点？
select b.*
from a,b
where a.bid(+)=b.bid
and level>1
start with a.bid is not null
connect by b.b_parentid=prior b.bid

如果是父节点的话，将b.b_parentid=prior b.bid改成
prior b.b_parentid=b.bid