One to Many Report Problem

Question

I have an Item table and an Orders table linked for which I want to select certain Items and related Orders. The tables are linked via an Item No field.  I want to select all items for which the total of (QOH + QOO - Reqmts) is negative.  There can be multiple Orders for each item, or there can be no Orders for an item.  The Items I want listed are those in the negative as stated above.
I have a formula which calculates Availability (QOH + open orders - requirements).  QOH and requirements are straightforward and in the Items table.  The open orders are a Running Total field for orders that are open and for which there is still a balance due. 
My problem is that my report only lists those Items that have Orders associated with them.  I also need Items that have no orders associated with them.  When I tinker with the join type and the enforcement I get way too much data returned.
Are there any suggestions on how I can get the desired result?
Thanks.

Answer 1

OK, I think I understand.
The problem you're facing here is that as soon as you use a field from the MOS table, you'll lose all the IM records which have no orders, because the MOS fields are all null for those records. Unless you 'protect' them, which is what I'm trying to explain.
The best place for you to start is with a simple query which doesn't include any fields from the MOS table, like {IM.IM_PROD_CODE} in "020" to "073". Try this without any MOS fields displayed in the report initially, and then add a couple. I don't think this will knock out your nulls, but it might. No formulas, just fields.
Now add the second line
and {MOS.MOS_STATUS} <= 1.00
This will knock out the nulls because you're accessing the MOS table in an unprotected way. The reason is that as soon as you use a null value in a formula, the record is automatically rejected.
But if you change your formula to something like this:
{IM.IM_PROD_CODE} in "020" to "073"
and ( isnull({MOS-IM-KEY})
    or ( not  isnull({MOS-IM-KEY} and {MOS.MOS_STATUS} <= 1.00 ) )
you should find that the null records stay.
Now if you've got another formula which accesses the MOS table, you need to cater for the nulls there too. For example, if you need to access the quantity of the item (lets say it's called Qty), you might need to do the following:
local numbervar Qty := if isnull({MOS.QTY} then 0 else {MOS.QTY};
and so on.
But because you're new to this you need to build it up slowly, watching that your null records don't disappear.
Andrew