Question

In this scenerio…

CREATE TABLE emp 
(
    empno  NUMBER(4) NOT NULL,
    ename  VARCHAR2(10),
    job    VARCHAR2(9),
    mgr    NUMBER(4),
    sal    NUMBER(7,2),
    deptno NUMBER(2)
);

INSERT INTO EMP VALUES(7782, 'CLARK', 'MANAGER', 7839, 2450, 10);
INSERT INTO emp VALUES(7369, 'SMITH', 'CLERK', 7902, 800, 20);
INSERT INTO EMP VALUES(7499, 'ALLEN', 'SALESMAN', 7698, 1600, 30);
INSERT INTO EMP VALUES(7521, 'WARD', 'SALESMAN', 7698, 1250, 30);
INSERT INTO EMP VALUES(7566, 'JONES', 'MANAGER', 7839, 2975, 20);
INSERT INTO EMP VALUES(7654, 'MARTIN', 'SALESMAN', 7698, 1250, 30);
INSERT INTO EMP VALUES(7698, 'BLAKE', 'MANAGER', 7839, 2850, 30);
INSERT INTO EMP VALUES(7788, 'SCOTT', 'ANALYST', 7566, 3000, 20);
INSERT INTO EMP VALUES(7839, 'KING', 'PRESIDENT', NULL, 5000, 10);
INSERT INTO EMP VALUES(7844, 'TURNER', 'SALESMAN', 7698, 1500, 30);
INSERT INTO EMP VALUES(7876, 'ADAMS', 'CLERK', 7788, 1100, 20);
INSERT INTO EMP VALUES(7900, 'JAMES', 'CLERK', 7698, 950, 30);
INSERT INTO EMP VALUES(7902, 'FORD', 'ANALYST', 7566, 3000, 60);
INSERT INTO EMP VALUES(7934, 'MILLER', 'CLERK', 7782, 1300, 10);

COMMIT;

SELECT LPAD(' ', 4  *(LEVEL - 1)) ||  empno || ' ' || mgr hier
   FROM emp
   start with mgr is null
   CONNECT BY PRIOR empno = mgr;

DROP TABLE emp;

The results look like this.

7839
    7566 7839
        7788 7566
            7876 7788
        7902 7566
            7369 7902
    7698 7839
        7499 7698
        7521 7698
        7654 7698
        7844 7698
        7900 7698
    7782 7839    
        7934 7782

It appears that during the connect by, the managers are ending up in ascending order.
Is there any way to control this behavior, so as to make them appear in descending order?

7839                  
    7782 7839         
        7934 7782   
    7698 7839         
        7900 7698   
        7844 7698     
        7654 7698     
        7521 7698     
        7499 7698     
    7566 7839         
        7788 7566     
            7876 7788 
        7902 7566     
            7369 7902 

Thanks

Evil

Answer 1

Use the “ORDER SIBLINGS BY” clause to order siblings in the hierarchy.

http://docs.oracle.com/database/121/SQLRF/queries003.htm

SELECT LPAD(' ', 4  *(LEVEL - 1)) ||  empno || ' ' || mgr hier
   FROM emp
   start with mgr is null
   CONNECT BY PRIOR empno = mgr
   ORDER SIBLINGS by empno desc;