SELECT TRANS_ID
FROM TRANS_INST
WHERE connect_by_isleaf=1
START WITH TRANS_ID =480242
CONNECT BY PRIOR UP_TRANS_ID = TRANS_ID;
说明：
表TRANS_INST(TRANS_ID，UP_TRANS_ID)
480242表示树的任何一个节点
TRANS_ID子节点
UP_TRANS_ID父节点
【转】oracle CONNECT BY PRIOR叶子节点查找根节点
原文：http://www.cnblogs.com/dirgo/p/6760125.html