Question

我正在尝试创建一个其他用户的父模型。这就是我现在所拥有的：

型号：

class User < ActiveRecord::Base
 .
 .
 .
  has_one :guardian_of_child
end


class GuardianOfChild < ActiveRecord::Base

  belongs_to :user, foreign_key: "guardian_id"
  has_many :users, foreign_key: "child_id"

end

迁移：

class CreateGuardianOfChildren < ActiveRecord::Migration
  def change
    create_table :guardian_of_children do |t|
      t.references :user, index: true

      t.timestamps
    end
  end
end

当我尝试访问＆＃39; guardian_id＆＃39;或者＆＃39; child_id＆＃39;

<% @guardian_of_children.each do |guardian_of_child| %>
  <tr>
    <td><%= guardian_of_child.user.guardian_id %></td>

它给了我这个错误：

undefined method `guardian_id' for nil:NilClass

我做错了什么？有人可以帮帮我吗？

Answer 1

我得到了它的工作。基本上是父母与子女关系模型。

  class User < ActiveRecord::Base

    has_many :guardian_of_children, foreign_key: "guardian_id"
    has_many :child_of_guardians, class_name: "GuardianOfChild", foreign_key: "child_id"

  end

  class GuardianOfChild < ActiveRecord::Base

    belongs_to :guardian, class_name: 'User', foreign_key: 'guardian_id'
    belongs_to :child, class_name: 'User', foreign_key: 'child_id'

  end

用户与其他用户的关系

1 个答案: