Rails 4 中ActiveRecord_Relation的未定义方法"资产"

Question

我有一个项目模型和资产模型。一个项目可以有多个资产(通过Carrier wave上传)

这是项目。rb

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

，这是资产。rb

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

在project_controller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 %>

我有错误未定义的方法'资产'项目::ActiveRecord_Relation:0x007fa60850dd08

Answer 1

您尝试在ActiveRecord::Relation对象上调用assets而不是Project实例，这就是您得到错误的原因。要修复它，可以这样做:

@assets = Asset.all

或者，确保您只获得与项目相关的资产:

@assets = Asset.joins(:project)