On Mon, 20 Jun 2011, Chris Travers wrote:
Well, for billing, there really ought to be an authoritative contact record. Thinking about this for emailing we might want to create a new contact_class record for billing email with a unique constraint on the (credit_id, contact_class) field where the class id is this one. PostgreSQL's partial unique indexes can help here.
I understand your reasoning for wanting a single contact for billing, but I will just observe, that I have at least one customer, wherein they expect me to send invoices for different classes of service, to different people within the company.
I don't know how common that is, and I can only think of that one case, but in it there are three people that I routinely send invoices to, either depending on the size of the transaction, or the type of services provided.
It's one customer for me, so I can work around it by manually mailing invoices and orders in those cases, but I thought I'd throw it out there as a point of discussion.
Luke