3 Replies Latest reply on Jan 24, 2017 8:20 AM by bsharp77

    Unique field (but only unique to a second field)

    bsharp77

      Hi guys,

       

      I'm stumped by a validation problem I'm having.

       

      I have a simple table that has the fields:

       

      Supplier ID

      Invoice Number

       

      All invoices are entered into this table and I need a way of validating that an invoice isn't entered twice for the same supplier by mistake.

       

      I want the invoice number to be unique to the supplier only

      (i.e: one invoice number could be repeated many times throughout the table, but is only allowed once for each Supplier ID).

       

      I hope I've explained this clearly enough - any help on how this could be achieved would be greatly appreciated!