Join constraints

From: Jernej Kase <zapp0_at_email.si>
Date: 21 Jan 2003 00:36:21 -0800
Message-ID: <915c8a9f.0301210036.4c8aae18_at_posting.google.com>

How can one set external constraints over join path using visio orm source diagram?

For example, let's say we have three objects:

	Owner (ownID)
	Building (buildID)
	Room (roomID)

And fact types:
	Owner is owner of zero or more Building / Building is owned by zero
or one Owner.
	Owner is owner of zero or more Room / Room is owned by zero or one
Owner.
	Room belongs to exactly one Building.

I would like to set the following constraint:
	Building b is owned by Owner xor Room r is owned by Owner, Room r

belongs to Building b.

Is there a way to describe this constraint?

Regards,

        Jernej Received on Tue Jan 21 2003 - 09:36:21 CET