Rails: 在定义关联之前不能有 has_many :through 关联

Question

正在将应用程序从 Rails 4.2.9 升级到 Rails 5.2.1。

通过许多令人讨厌的部分更新依赖项和诸如此类的东西，最终在 console 中有了应用程序运行，现在试图在 server 上访问页面。部分页面加载但其他页面：

Cannot have a has_many :through association 'User#clubs' which goes through 'User#memberships' before the through association is defined.

不清楚 Rails 5 中可能发生了什么变化来触发这个？甚至不确定从哪里开始寻找。

想法？

下面调用的行似乎失败了：

class ViewableStories
  ...
  def for_user
    Story
      .includes(:publications)
      .references(:publications)
      .where(
        stories[:user_id]
        .eq(@user.id)
        .or(
          publications[:club_id]
          .in(@user.club_ids)        <<==== execution halts
          .and(
            publications[:publish_on]
            .lt(Date.today)
            .or(publications[:publish_on].eq(nil))
          )
        )
      )
  end
end

这是从 model/story.rb

调用的

  def self.viewable_published_stories_for(user)
    ViewableStories
      .for_user(user)
      .includes(:cover_image, :user, :table_of_contents)
      .published
      .chronological
  end

Answer 1

这可能只是您模型中的一个排序问题。 has_many 必须在 has_many through 之前。

所以现在，您可能有：

class User < ApplicationRecord
  ...
  has_many :clubs, through: :memberships
  has_many :memberships
  ...
end

您只需将 has_many :memberships 移动到 has_many through 上方：

class User < ApplicationRecord
  ...
  has_many :memberships
  has_many :clubs, through: :memberships
  ...
end

Rails: 在定义关联之前不能有 has_many :through 关联

Rails: Cannot have a has_many :through association before association is defined

ruby-on-rails

activerecord

has-many-through

activerecord-relation