比如模块表 mod?
字段?
number modId?
number parentModId?
varchar modName?

从下往上查?
select * from mod m start with m.modId = ? connect by prior m.parentModId = m.modId?

从上往下查?
select * from mod m start with m.parentModId = ? connect by prior m.modId= m.parentModId?

这样可以把它的所有关联项都查出来，?
一定要注意connect by prior后面条件的顺序。?