nil正在为载波中的图像保存

Question

产品可以有多个图像。但是每张图片应该一次上传一张。

以下是产品的架构

create_table "products", force: :cascade do |t|
    t.json     "images"
  end

这是载波安装

class Product < ActiveRecord::Base
    mount_uploader  :images, ProductUploader

end

这是载波发生器

class ProductUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  # include CarrierWave::RMagick
  # include CarrierWave::MiniMagick

  # Choose what kind of storage to use for this uploader:
  storage :file
  # storage :fog

  # Override the directory where uploaded files will be stored.
  # This is a sensible default for uploaders that are meant to be mounted:
  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  # Provide a default URL as a default if there hasn't been a file uploaded:
  # def default_url
  #   # For Rails 3.1+ asset pipeline compatibility:
  #   # ActionController::Base.helpers.asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
  #
  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
  # end

  # Process files as they are uploaded:
  # process scale: [200, 300]
  #
  # def scale(width, height)
  #   # do something
  # end

  # Create different versions of your uploaded files:
  # version :thumb do
  #   process resize_to_fit: [50, 50]
  # end

  # Add a white list of extensions which are allowed to be uploaded.
  # For images you might use something like this:
  # def extension_whitelist
  #   %w(jpg jpeg gif png)
  # end

  # Override the filename of the uploaded files:
  # Avoid using model.id or version_name here, see uploader/store.rb for details.
  # def filename
  #   "something.jpg" if original_filename
  # end

end

这是视图

<%= simple_form_for @product, method: :post, url: save_image_path do |f| %>

        <%= f.file_field :avatar_1 %>

        <%= f.submit :submit %>

    <% end %>

这是控制器

class UploadController < ApplicationController
  def show
    @product = Product.find(1)
  end

  def create
    byebug
    @product = Product.find(1)
    @product.images = params[:product][:avatar_1]
    @product.save

  end


end

但是nil正在更新产品图像而不是图像。有人可以帮我解决这个问题。