Hierarchy

select level, LPAD('  ',5*(lavel-1))||ename, empno, job,mgr,sal

from emp

start with job = 'president'

connect by prior empno = mgr;

 

 

 

 

------------------------- 显示结果------------------------------

 

 

level   Lpad（。。。）               EMPNO         JOB                       MGR

1        KING                                0000          PRISEDENT           

2              JONES                        0100         .....                        0000

3                    SCOTT                  0110               ....                   0100

4                           ADAMS           0111             ....                     0110

3                    FORD                    0120                                      0100

4                           SMITH            0121                                      0120

2              BLAKE                         0200                                      0000

3

3                .....

3                  .....

3                    ....

 

 

 

 

层次结构用到人事系统或BBS 的 回复中使用。。