1. 查询父级ID为0的所有的子数据(向下递归)
    SELECT * FROM TEST START WITH PARENT_ID = '0' CONNECT BY PRIOR ID = PARENT_ID;

  2. 查询ID为123的所有的父级(像上递归)
    SELECT * FROM TEST START WITH ID = '123' CONNECT BY ID = PRIOR PAERENT_ID;