Combining different measures based on different dates in a single table

Question

Hi,
I'm attempting to produce a report that gives two counts of items in a database, the first based on the date added to the database, the second based on the date marked as deleted, all reported by month over the last 12 months.
The following pertinent fields are available for use in the query builder:
Item ID, Entry Date, Deleted Date, End date of previous month, End date of previous month last year.
The report should look something like this:
Month.....Total Items....Additions....Deletions
May 08....54.............. 43...............3
Apr 08.....654..............600.............0
Mar 08.....654..............0................0
Feb 08.....654.............10...............10
Jan 08.....53................0................601
Jul 08......96................3................2
Jun 07.....46................4................54
Month:
=If(DaysBetween([Last Day Of Prev Month Prev Year];[Entry Date])>0;
+Month([Entry Date]) + " " + FormatNumber(Year([Entry Date]);"####");+
"Previous Balance")
Total Items:
=RunningSum(Count([Item Id]))-RunningSum(Count(Item ID) Where(Not(IsNull([Deleted Date]))))
Item Additions:
=Count([Item ID])
Item Deletions:
=Count([Item ID]) Where(Not(IsNull([Deleted Date])))
The part I'm having problems with is splitting the results by month, such that the number of deletions equals the number of items deleted that month, rather than the number of items deleted that month of the items added that month. I.e. I need to split by month on the additions date for the additions column and by month on the deletions date for the deletions column.
At the moment, if the 54 items deleted in Jul 07 were originally added to the DB in, say Mar 06, then they would show up as deletions in Mar 06 - because the Month column is being split out based on Additions date. Of course I could reverse this and split the months out by deletion date, but then I would have the same problem in reverse - I can't see any way of doing both.
Any ideas?
I hope I've explained that so that it makes vague sense, please ask if it doesn't!
Many thanks in advance,
Steve

Answer 1

Have you tried splitting this out into 2 seperate queries the first to return the additions by month and the second to return the deletions by month. You should then be able to merge the date dimensions and report both additions and deletions against a single date dimension.
Regards,
Mike