Query to Find Root ID in ABAP

Question

Suppose we have a database table with values as following :
ItemID  -
               ParentID
A1         -
              Null
A2          -
             A1
A3           -
            A1
A4           -
            A3
A5           -
            A3
Now I want to find the Root ParentID of A5 , that would be A1 in this case as the corresponding ParentID of A1 is NULL.
How should I  get the desired result ?
Thank You
Saurabh
Edited by: Saurabh Kapoor on Sep 23, 2010 8:02 AM

Answer 1

Hi Saurabh,
Use this peace of code....
types : BEGIN OF x_data,
        child type char2,
        a      type i,
        end of x_data.
data : wa_data type x_data.
select single a~child count(*) as a into wa_data
  from zamit_test as a INNER JOIN zamit_test as b
       on a~parent ne b~child
  GROUP BY a~child.
IF sy-subrc = 0.
  BREAK-POINT.
ENDIF.
In the o/p workarea the value of child is the top most node.
Amitava
Edited by: Amitava De on Sep 23, 2010 1:32 PM