oracle中如何編寫樹級代碼

oracle
這是在2002年給一個制衣廠做系統的時候寫的，請大家多批評指正！

create table Dept(
 DepartNO  varchar2(10),
   DepartName  varchar2(20),
 TopNo    varchar2(10));

insert into Dept values('001','懂事會','0');
insert into Dept values('002','總裁辦','001');
insert into Dept values('003','財務部','001');
insert into Dept values('004','市場部','002');
insert into Dept values('005','公關部','002');
insert into Dept values('006','銷售部','002');
insert into Dept values('007','分銷處','006');
insert into Dept values('008','業務拓展處','004');
insert into Dept values('009','銷售科','007');

CREATE TABLE TempDept
(
 TempdeptNo    char(4), /*部門編號*/
 TempdeptName   varchar2(20), /*部門名稱*/
  UpperTempdeptNo  char(4), /*上層業務編號*/
  UpperTempdeptName  varchar2(20), /*上層業務名稱*/
 TempdeptLevel   number(4) /*部門所處的層級*/
);

select departname
from dept
connect by prior departno=topno
start with topno='0';

select a.departname top ,b.departname next
from dept a,dept b
where a.departno=b.topno;

select lpad(departno,level*2+length(departno),'\')
from dept
start with topno='0'
connect by prior departno=topno;

select departno,departname,level ||'\'|| topno
from dept
start with topno='0'
connect by prior departno=topno;

select lpad(departno,level*2+length(departno),' ')
from dept
start with topno='0'
connect by prior departno=topno;

select lpad(departno,level*3,' ')
from dept
start with topno='0'
connect by prior departno=topno;

create or replace function GetLevel(TempNo varchar2)
return varchar2
IS
 Result  varchar2(20);
 cursor CurLevel(curTempNo varchar2)
 is
 select departNo
 from dept
 connect by prior departNo = TopNo
 start with TopNo = curTempNo;
begin
 open CurLevel;
 for v_sor in CurLevel(TempNo) loop
   Result:=Result || '/' || v_sor.curTempNo;
 end loop;
 return(Result);
 close CurLevel;
  dbms_output.put_line('success');
end GetLevel;


REM************************************************************
REM**********   產生部門之間形成的樹結構     ******************
REM********** 功能:輸入部門後自動產生該部門  ******************
REM**********      及其子部門之間的樹關係()  ******************
REM********** 輸入參數：部門編號ParaDeptId   ******************
REM************************************************************

CREATE OR REPLACE procedure getAllSubDeptId(ParaDeptId varchar2)
IS
    DeptNo1       varchar2(4);     /*存放部門編號*/
    UpperDeptNo1  varchar2(4);     /*存放該部門的上層業務編號*/
    UpperDeptNo2  varchar2(4);     /*存放查詢同級上層業務編號*/
    UpperDeptNo3  varchar2(4);     /*存放查詢的上層業務編號*/
       level         number;          /*部門所處層級*/
    DSql          varchar2(100);   /*動態SQL字串*/
    CURSOR getDept IS
       select DepartNO,TopNo
       from dept
       where DepartNo != ParaDeptId;
BEGIN
 --DSql :='create table tempdept(TempdeptNo,TempdeptName,UpperTempdeptNo,
  --UpperTempdeptName,TempdeptLevel)';
 --EXECUTE IMMEDIATE DSql;
   DSql :='TRUNCATE TABLE TempDept';
   dbms_output.put_line(0);
   EXECUTE IMMEDIATE DSql;
   dbms_output.put_line(1);
   insert into TempDept values(ParaDeptId,Null,Null,Null,0);
   dbms_output.put_line(2);
   open getDept;
   fetch getDept into DeptNo1,UpperDeptNo1;
   WHILE ( SQLCODE = 0 )
   LOOP
      level := 1 ;
      UpperDeptNo3 := UpperDeptNo1;
      WHILE ( UpperDeptNo1 is NOT NULL )
      loop
         if (UpperDeptNo1 = ParaDeptId) then
            insert into tempdept           values(DeptNo1,NULL,UpperDeptNo3,NULL,level);
           exit;
        else
           UpperDeptNo2 := UpperDeptNo1;
           select topNo into UpperDeptNo1
           from  dept
           where Departno= UpperDeptNo2;
           if UpperDeptNo2 != UpperDeptNo1
    then
                level := level+1;
           end if;
         end if;
      END LOOP;
     fetch getDept into DeptNo1,UpperDeptNo1;
   END LOOP;
   close getDept;
END;
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