Oracle tree structure query statement

Select rpad ('', 4 * (LEVEL-1), '--') | name as name, CONNECT_BY_ROOT name" ROOT ", www.2cto.com CONNECT_BY_ISLEAF" ISLEAF ", LEVEL, t. *, SYS_CONNECT_BY_PATH (t. name, '/') "PATH" from sys_department t start with t. required mentid = 1 connect by nocycle prior t. required mentid = T. parent1_mentid 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