ruby-on-rails-4 - 为什么当我在 rails 4 数据库中使用载波上传图像时会回滚？

Question

我尝试在 rails 4 中使用carrierwave 保存图像文件，但是当提交按钮单击时数据库回滚？？？为什么 ？

如果我不选择要上传的图像而仅发送字符串，则一切正常，但如果我发送图像文件，则会出现如下错误:

TypeError: can't cast ActionDispatch::Http::UploadedFile to string: INSERT INTO "items" ("created_at", "description", "image", "name", "store_id", "sub_items", "title", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?)
   (0.2ms)  rollback transaction
*** ActiveRecord::StatementInvalid Exception: TypeError: can't cast ActionDispatch::Http::UploadedFile to string: INSERT INTO "items" ("created_at", "description", "image", "name", "store_id", "sub_items", "title", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?)

我的看法 :

<%= form_for @items, :url => dashboard_create_items_path(@store.id), :html => {:multipart => true} do |f| %>
  <%= f.label :name, 'Name' %>
  <%= f.text_field :name %><br />
  <%= f.label :title, 'Title' %>
  <%= f.text_field :title %><br />
  <%= f.label :image, 'Image' %>
   <%= f.file_field :image %><br />
  <%= f.label :description, 'Description' %>
  <%= f.text_field :description %><br />
  <%= f.label :sub_items %><br>
  <%= f.select :sub_items, options_for_select([["true", true], ["false", false]]), :selected => 'true' %><br />
  <%= f.submit %>
<% end %>

我的 Controller :

def create_items    
    store = Store.find(params[:id])
    @items = store.items.create(item_params)

    if @items
      redirect_to dashboard_show_items_url(@items.id, store.id)
    else
      redirect_to dashboard_new_items_url
    end
  end

private

    def item_params
      params.require(:item).permit(:name, :title, :image, :description, :sub_items, :store_id)
    end

请告诉我什么时候我错了？之前谢谢

Answer 1

您可能会看到此错误消息，因为 Carrierwave 尚未在您的模型中初始化。

需要将载波方法 mount_uploader 添加到模型中的图像字段中，如下所示:

class Item < ActiveRecord::Base
  mount_uploader :image, ImageUploader
end

(有关更多详细信息，请参阅 docs)