Child reports and bind variables

Question

I'm working on a user defined parent/child report. What I'm having an issue with is using a parents bind variable value in a child. To simpify my example:
The master query is:
select count(*), document
from download_audit
where activity_date > sysdate-:DAYS
group by document
which returns a count of downloads for each document in the last :DAYS days. I want the child report to then list the person that downloaded a selected document:
select document, user_id, activity_date from download_audit
where activity_date > sysdate - :DAYS
and document=:DOCUMENT
This does not work because the initial :DAYS bind isn't sent to the child.
If I add the :DAYS as a selected column to the master sql it works. e.g.
select count(*), document, :DAYS days
from download_audit
where activity_date > sysdate-:DAYS
group by document
My question is, do child bind variables all have to be selected columns in the master query or is there a way to have a "global" bind variable that gets carried from master to child?
I'm using SQL Developer 3.2.20.09 on OS X Lion
Edited by: RoboMan on Nov 16, 2012 11:23 AM

Answer 1

I agree whole heartedly :)
If you want to make things even more interesting, create some 3rd generation child reports and carry the bind variables throughout the multiple levels - here's an example
http://www.thatjeffsmith.com/archive/2012/09/grandparent-parent-child-reports-in-sql-developer/