Three-table sql join

three-table-join.sql

-- I have the tables `category`, `subscription` and `document`. Document
-- references subscription, and subscription references category. I am trying to
-- get the category name based on a documents PK. I am doing something like this:

SELECT category_name FROM categorias
    INNER JOIN subscription ON category_fk = category_pk
    INNER JOIN documents ON subscription_fk = document_pk
    AND document_pk = 14;