查询的表复合递归查询条件，父节点，子节点 table tree
SELECT * FROM tree START WITH id = 2 CONNECT BY PRIOR pid = id -- 递归查询父节点 union SELECT * FROM tree START WITH id = 2 CONNECT BY pid = PRIOR id; -- 递归查询子节点
oracle递归查询
原文：http://www.cnblogs.com/likun10579/p/6714024.html
