用SQL描述树

/*40条(1层)

SELECT COUNT(*) FROM t01_mwfl WHERE AZFSDM=01 AND LEVEL=1 START WITH PID=0 CONNECT BY  PRIOR ID=PID

*/

SELECT * FROM t01_mwfl WHERE AZFSDM=01 AND LEVEL=1 START WITH PID=0 CONNECT BY  PRIOR ID=PID 



SELECT LEVEL FROM t01_mwfl WHERE AZFSDM=01 AND LEVEL=1   START WITH PID=0 CONNECT BY  PRIOR ID=PID 



/* 210条(2层)

SELECT COUNT(*) FROM t01_mwfl WHERE LEVEL =2 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID

*/

SELECT * FROM t01_mwfl WHERE LEVEL =2 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID 



SELECT LEVEL FROM t01_mwfl WHERE LEVEL =2 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID 



/*395条(3层)

SELECT COUNT(*) FROM t01_mwfl WHERE LEVEL=3 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID 

*/

SELECT * FROM t01_mwfl WHERE LEVEL=3 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID 



SELECT LEVEL FROM t01_mwfl WHERE LEVEL=3 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID 

select * from WQGM_2V.t01_mwfl where  azfsdm='01' and pid=0 and id  in 

(

--通过字符串处理

select substr(substr(path,2),1,instr(substr(path,2),'/')-1) pid  from (

--取大于某层的树路径

SELECT sys_connect_by_path(id,'/') as path FROM WQGM_2V.t01_mwfl WHERE LEVEL>2 AND AZFSDM=01  START WITH PID=0 CONNECT BY  PRIOR ID=PID

)

)





/*三层*/



 /**/

SELECT ID,NAME,ROWNUM FROM WQGM_2V.t01_mwfl

WHERE PID=0 

AND AZFSDM='01' 

AND ID IN

(

   SELECT ID FROM WQGM_2V.t01_mwfl  MINUS 

(

   SELECT ID FROM WQGM_2V.t01_mwfl  MINUS 

   SELECT PID FROM  WQGM_2V.t01_mwfl 

)

)

 ORDER BY ID

 /**/

 SELECT ID,NAME,ROWNUM,LEVEL FROM WQGM.t01_mwfl 

WHERE PID=0 

AND AZFSDM='01'

AND ID IN

(

   SELECT ID FROM WQGM.t01_mwfl  MINUS

(

   SELECT ID FROM WQGM.t01_mwfl  MINUS 

   SELECT PID FROM  WQGM.t01_mwfl 

)

)

 START WITH PID=0 CONNECT BY PRIOR ID=PID 

 ORDER BY ID



/*四层*/

SELECT b.id,a.path,a.name FROM
(
SELECT id FROM WQGM.t01_mwfl MINUS
(
SELECT id FROM WQGM.t01_mwfl MINUS
SELECT pid FROM WQGM.t01_mwfl
)
) b
,
(
SELECT id,sys_connect_by_path(id,'/') as path,sys_connect_by_path(name,'/') as name,level as lv
FROM WQGM.t01_mwfl WHERE azfsdm=01 START WITH pid=0 CONNECT BY PRIOR id=pid
) a
WHERE a.id=b.id AND lv>1