Question

oracle 递归 通过子节点查根节点

SELECT sectype.thekey, sectype.name, sectype.thelevel
FROM sectype
start with sectype.thekey = '8565'
connect by prior sectype.thelevel = sectype.thekey

其中8565是子节点的id。我现在想通过这个子节点查到对应的根节点的id，该如何查询？

Answer 1

根节点的thelevel 应该为null，可以加个条件 where sectype.thelevel is null 。

SELECT sectype.thekey, sectype.name, sectype.thelevel
FROM sectype
where sectype.thelevel is null
start with sectype.thekey = '8565'
connect by prior sectype.thelevel = sectype.thekey

Answer 2

请列出表结构，查询要求等等 这样才能方便为你解题。