SQL找关系节点
表如下格式（父与子是多对多的关系）
Parent_Dwg_NoParent_Rev_NoDwg_NoDwg_Rev
0029SAA0010029GAP004
0029GAP0045247GAK007
0029GAP0045247GAS005
0029GAP0045247GBJ002
。。。。。。
5247GBJ0030098GCJ000
5247GBJ0030223GAM001
5247GBJ0030118GBL000
能否通过0223GAM 001找到根0029SAA 001
[解决办法]
select *
from (select Parent_Dwg_No, Parent_Rev_No, rownum num
from Rt_basic_data
start with Dwg_No||Dwg_Rev = '0223GAM001'
connect by prior Parent_Dwg_No||Parent_Rev_No = Dwg_No||Dwg_Rev
order by num DESC)
where rownum = 1
