scribu/wp-posts-to-posts — Issue #116: one-to-many Cardinality not always enforced
Author: markjaquith
Created: 2012-02-22 08:17:26+00:00
State: open

In a one-to-many relationship, it is possible to violate the policy.

Say that the post type `father` is connected to the post type `child` with `one-to-many` specified. i.e. one father can have many children, but a child can only have one father (biologically speaking!).

You cannot violate the policy by trying to add two `father` connections to a single `child`. But you **can** have two different `father`s claim the same `child`. You just have to do it from the `father` edit screen. When displaying the list of possible things to link to, "many" items in a `one-to-many` relationship that are already have a relationship with another "one" item, should not appear.