如何将多个模型与一个将在Rails中统治它们的模型联系起来？

class User< ApplicationRecord
  has_one :profile
end

class Profile< ApplicationRecord
  belongs_to :user
end

class Department< ApplicationRecord
  has_many :employees
end

class Employee< ApplicationRecord
  belongs_to :department
end

class Course< ApplicationRecord
  has_and_belongs_to_many :students
end

class Student< ApplicationRecord
  has_and_belongs_to_many :courses
end

class Comment< ApplicationRecord
  belongs_to :commentable, polymorphic: true
end

class Article< ApplicationRecord
  has_many :comments, as: :commentable
end

class Video< ApplicationRecord
  has_many :comments, as: :commentable
end