ruby-on-rails - 两个外键的作用域

Question

我有以下架构:

我希望可以选择为外键(author_id 和 editor_id)以及单独的外键(例如 author_proposals 和 editor_proposals)，我需要有延迟或急切加载它们的选项(例如 User.includes(:proposals) 或没有它用连接)。

更新:

#I have the scopes which is like this:
class User < ActiveRecord::Base
  has_many :author_proposals, class_name: 'Proposal', foreign_key: :author_id
  has_many :editor_proposals, class_name: 'Proposal', foreign_key: :editor_id
end

class Proposal < ActiveRecord::Base
  belongs_to :author, class_name: 'User', foreign_key: :author_id
  belongs_to :editor, class_name: 'User', foreign_key: :editor_id
end

但我需要一个通用的，它会给我所有的建议(包括 author_proposals 和 editor_proposals)，它也会急切地加载它们。我应该在 has_many 上使用条件吗？

Answer 1

我会做这样的事情:

class User < ActiveRecord::Base
  has_many :authored_proposals, class_name: 'Proposal', foreign_key: :author_id
  has_many :editored_proposals, class_name: 'Proposal', foreign_key: :editor_id

  def proposals
    Proposal.where('author_id = :id OR editor_id = :id', { id: id }).distinct
  end
end

class Proposal < ActiveRecord::Base
  belongs_to :author, class_name: 'User', foreign_key: :author_id
  belongs_to :editor, class_name: 'User', foreign_key: :editor_id

  def users
    User.where(id: [author_id, editor_id].uniq)
  end
end