查询一个树的所以叶子节点:
方法1: select 'A',id,s_id, level from test where connect_by_isleaf =1 //叶子节点 start with id = 'A' connect by prior s_id = id //方法2: select 'A', a.s_id from ( select * from test start with id = 'A' connect by prior s_id = id ) a where not exists (select 1 from test t1 where t1.id = a.s_id )