Generic table associations

I am looking for one table to have a one-to-many relationship with
many other tables.
For example, I have a table ‘collections’, and I have other tables
‘photos’, ‘videos’, ‘mp3s’ etc.

Is there a way to get this using rails?

This is kind of the opposite of a polymorphic relationship:
‘With polymorphic associations, a model can belong to more than one
other model, on a single association’

Here, I want one model to have a one-to-many relationship with records
from many other tables.

I know I could create the join table myself with three fields: the
collection_id, the name of the table and the record id inside it, and
write SQL to retrieve all the records that belong to a collection.But
that is cumbersome.

Another way might be to put has_many entries for each of photos,
videos, mp3s, in the collections table,
and belongs_to :collection entries in each of photos, videos, mp3s,
and create appropriate references
in the collections table. If later I want to add some other
type, say dvds, I have to modify the collections table. I guess this
is not too bad, if no easier method exists.

Django (Python) has a notion of GenericRelation and that is exactly
what I am looking for.