oracle 树结构查询

SELECT RPAD(' ', 4 * (LEVEL-1), '--') || name as name,
       CONNECT_BY_ROOT name "ROOT",
       CONNECT_BY_ISLEAF "ISLEAF",
       LEVEL,
       t.*,
       SYS_CONNECT_BY_PATH(t.name, '/') "PATH"

  from sys_department t
START WITH T.DEPARTMENTID = 1
CONNECT BY NOCYCLE PRIOR T.Departmentid = T.PARENTDEPARTMENTID
order siblings by t.departmentid;



SELECT RPAD(' ', 2 * (LEVEL - 1), '-') || Tn_Id,
       CONNECT_BY_ROOT Tn_Id "ROOT",
       CONNECT_BY_ISLEAF "ISLEAF",
       LEVEL,
       t.*,
       SYS_CONNECT_BY_PATH(t.Tn_Id, '/') "PATH"

  from (
  (SELECT c.tn_id, c.tn_name, c.parent_id, c.orders
           FROM tree_node_c c
          where c.proj_phase = 'PD'
            and (c.view_mode = 2 or c.view_mode = 0) )
            union
        select d.tn_id, d.tn_name, d.parent_id, d.orders
           from tree_node_d d
          where d.proj_id = '15-B154C'
            AND (d.view_mode = 2 or d.view_mode = 0)
            and d.proj_phase = 'PD'

          ) t
START WITH T.Parent_Id = 'DP1_000'
CONNECT BY NOCYCLE PRIOR T.Tn_Id = T.PARENT_ID
order siblings by orders