递归SQL---树形结构

select  id,mer_no,mer_level from t_test a  start with  a.id='111111111111'   connect by prior id=parent_mer_id;------向下遍历

结果类似：

0级

1级

2级

...

select  distinct  id,mer_no,mer_level from t_test a start with   a.id='111111111111'   connect  by prior parent_mer_id=id;------向上遍历

结果类似：

...

2级

1级

0级