How can i achieve Outerjoin type of results using Reports Datalink option

Question

Hi,
i am developing a Oracle Report. i am using Datalink to maintain parent-child relationship between 2 queries. If no matching value found then i want to return 0 Records. how to achieve this.
Ex: I have 2 tables like Dept & EMP
DEPT has 2 rows HR and FINANCE
I have only one employee in HR and no employee in FINANCE.
I am using the below datalink properties:
SQL clause : WHERE
CONDITION ; =
PARENT GROUP: DEPT
PARENT Column : DEPTID
CHILD QUERY : EMP
CHILD Column : DEPTID.
In the report it is showing matching columns without any issues> i want non matching columns also with Zero employess like
HR     1
FINANCE 0
I need OUTER JOIN kind of thing. How can i achieve this. Just i have written one example. I have very complex query to implement this and datalink is absolutely necessry for me. Any help please.

Answer 1

Following can be checked in order to return column value from child Group to Parent Group at data modal.
a. create a PlaceHolder column ( say CP_1 and CP_2) at parent Group.
b. create one Formula column at each Child group ( say cf_1 and cf_2 )
c. write code at formula to return reg_emp as ( say for cf_1)
srw.reference(:cp_1);
:cp_1 := :rep_emp;
for unreg_emp as
srw.reference(:cp_2);
:cp_2 := :unreg_emp;
.. this way now reg_emp and unreg_emp counts can be made available to parent Group.
To get a difference and return "Yes" or "No" write formula column at Parent Group ..
Create a Formula column ( say cf_3) at parent group
write following
begin
if :cp_1 = :cp_2 >0 then
return 'Yes';
else
return 'No';
end if;
end;
Now use this formula as source to show value at layout under Parent Repeating Frame.
Hope this helps..