Start with Connect By: What if Parent is the Child?

Question

Version : 11g
Hi There,
I had a question regarding Start with Connect by.
The following is an example from the ORacle help from the Emploees table
select case when connect_by_isleaf = 1 then 0 when level = 1 then 1 else -1 end as status,
       level,
       First_name as title,
       NULL  as icon,
       EMPloyee_id as value,
       First_name as tooltip,
       NULL  as link
from EMPLOYEES
start with Manager_id ='171'
connect by prior EMPLOYEE_ID = Manager_id
order siblings by First_nameNow this works fine and shows the levels. In the help the start with is actually
start with Manager_id is nullNow if we use a lowest level employee using something like
start with Manager_id = '171'no rows are returned. This is because there are no child records for this employee (he is not a manager).
However, is it possible to atleast show this one record as the output? Any suggestions?
Thanks,
Ryan
Edited by: ryansun on Dec 10, 2012 10:51 PM

Answer 1

One way
start with
  ( manager_id ='171'
    or
       employee_id='171'
       and '171' not in (
                         select distinct manager_id
                         from employees
                         where manager_id is not null
  )Edited by: jeneesh on Dec 11, 2012 12:35 PM