Question

我有一个项目模型和资产模型。一个项目可以有很多资产（由Carrier wave上传）

这是project.rb

class Project < ActiveRecord::Base
  validates :title, length: { maximum: 150 } ,uniqueness: true, presence: true
  has_many :assets
end

这里是asset.rb

class Asset < ActiveRecord::Base
  mount_uploader :attachment, AttachmentUploader 
  belongs_to:project
end

在project_controller.rb的index方法中，我有以下实例变量：

class ProjectsController < ApplicationController
   def index
     @projects = Project.all
     @assets = @projects.assets.all
   end

  def project_params
    params.require(:project).permit(:title,assets_attributes: [:id,:project_id,:attachment])
  end
end

这是视图，index.html.erb

<% @assets.each do |p| %>
    <td><%= number_to_human_size(p.attachment.size) %></td> 
<% end %>

我有错误的未定义方法`assets＆＃39; for Project :: ActiveRecord_Relation：0x007fa60850dd08

Answer 1

您尝试在assets对象而不是ActiveRecord::Relation实例上调用Project，这就是您收到错误的原因。要修复它，你可以这样做：

@assets = Asset.all

或者，确保只获得与项目相关的资产：

@assets = Asset.joins(:project)

Rails 4中ActiveRecord_Relation的未定义方法`assets'

1 个答案: