Here's the thing :
I have a table with languages (name, label, id).
I'd like another table people with primary_language and
that should refer to a language_id.
primary_language -> language_id
secondary_language -> language_id
Because I got 2 references, I don't know how I can do. I think I have to
explicitly say in the Person and Language model that primary_language
and secondary_language is a language_id. How can I do ?