Got two questions about Access autonumbering behavior:
1. Is it true that under certain conditions the autonumbers can be re-used or renumbered by Access? Is this a reason to avoid using them for any sort of external numbering reference (such as an invoice number or account number)?
2. I found a particularly troubling issue when using subforms. If a user attempts to add a new entry in the subform before entering any data in the parent form and then moves off that parent record (before the parent table creates an autonumber) the child record gets lost forever.
I have a Ordering program that has a main form with a subform on it. On the main form I have OrderID and the subform primary key is OrderDetailsID. I find that if you keep it separate, but join them by those keys, it shouldn't matter what section you enter data in first.