On 20 May 2015, at 11:18pm, Scott Doctor <scott at scottdoctor.com> wrote:
> I can see the issue. For instance, an invoice ID related to inventory, where > the invoice ID is the PK number. Two salesmen on their iPads take an order > where their local database assigns the same PK number. When merged you have > two invoices with the same ID. Seems a classic problem with non centralized > input. A second field, such as salesman ID, would need to squashed into that > invoices PK number to guarantee a uniqueness to the number, assuming every > salesman has a unique ID. Yep. That's the problem and that's one way to solve it. The other is to give each device a short unique number, and have that number in the UUID the device can generate. Given that UUIDs are normally expressed as Hex, the device code is normally three or four higits. Simon.
