适用于范围内用户的HABTM

Question

如何在有作用域的用户（assigned_user）之间实现HABTM关系 和评估模型，我有users和assessments模型

user.rb

  devise :database_authenticatable,
         :recoverable, :rememberable, :validatable

  has_many :assessments
end

assessment.rb

class Assessment < ApplicationRecord
  belongs_to :user
  has_and_belongs_to_many :assigned_user, class_name: 'User'

  scope :assigned_user, -> { where('user.role == proctor') }
end

如何在范围assigned_user和assessments之间创建联接表