有一个表 ID GID
ID GID
-- ---
1 0
2 0
3 1
4 3
5 2
6 3
GID是上级ID，GID有权限看所有子层的数据
现在想要查出结果为
ID GID
-- ---
1 0
2 0
3 0
4 0
5 0
6 0
3 1
4 1
6 1
5 2
4 3
6 3
请教大神，要如何查出。。。
------解决方案--------------------
with t as(
select '1' id,'0' gid from dual
union all
select '2','0' from dual
union all
select '3','1' from dual
union all
select '4','3' from dual
union all
select '5','2' from dual
union all
select '6','3' from dual
)
select t.id, connect_by_root gid gid
from t
start with gid in (select gid from t)
connect by prior id = gid;
ID GID
-- ---
1 0
3 0
4 0
6 0
2 0
5 0
3 1
4 1
6 1
5 2
4 3
6 3
12 rows selected