Re: Conditional Relationships ?

Henry,

  Maybe I'm missing something, but I would think if an invoice can cover just part of an order, then you just want to relate the invoices to the Order_Items table (which presumably is in turn related to the Orders table).

  You should be able to write procedures or triggers to make it easy to associate an invoice with an entire order (so the user doesn't have to specify the individual items), and you can also see whether an order is fully invoiced by searching for order items for that order that are not invoiced.

  I suspect I'm missing some reason why relating an invoice to all the items of an order (which I'm suggesting for a full-order invoice) is not the same as relating an invoice directly to an order, so let me know.

[Apologies for sending separate replies to the two groups - for some unknown reason Mozilla just told me I can't send to two news servers at once, though it's hard to believe I've never done that successfully before...]

Steve Kass
Drew University

Henry Craven wrote:

>I'm curious as to how one would go about setting up
>and enforcing a Conditional Relationship.
>
>An example would be :
>
>Orders Table
>Order_Items table
>Invoices Table
>Invoices_Intersect Table
>
>The Invoices_Intersect has Foreign Keys for
>Invoices
>Orders
>Order_Items
>
>The relationship needs to be enforced so that the Invoice
>relates to EITHER the Order ( as a Whole ) 1 -2- 1
>OR the Order_Items ( Order part Shipped ) n -2- 1
>BUT NOT both.
>
>TIA
>--
>Henry Craven
>
>
>
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Received on Sun Dec 29 2002 - 07:23:04 CET