sql 基础 五 树查询

select * from(select t.postid,        t.name,        t.parentidfrom gaus_postinfo tstart with t.parentid ='GAUS_POSTINFO_8e29081b-8cba-41be-a1da-fdba0ba94a86' connect by prior t.postid = t.parentid )treeTable--查看树select * from(select a.menu_name,       a.parent_id,       level "层次",       sys_connect_by_path(menu_name, '.') "合并层次",       prior a.menu_name "父节点",       connect_by_root a.menu_id "根节点",       decode(connect_by_isleaf, 1, a.menu_name, null) "子节点",       decode(connect_by_isleaf, 1, '是', '否') isleaffrom ipbp_webmenu astart with a.parent_id =1003 --从parent为空开始扫描connect by prior a.menu_id = a.parent_id --以child为父列连接parentorder siblings by menu_id desc --对层次排序)treeTablewhere treeTable.isleaf='是'