How to make compound primary keys with FactoryGirl Gem

Question

How to execute compound keys using FactoryGirl with a relation below

Portal (uuid, name)

listing (uuid, portal_uuid, name)

location (uuid, portal_uuid)

here the list and location have a composite primary key (uuid, portal_uuid) .

I tried different ways, but can't solve it. Has anyone encountered this problem, pls help?