Question

我正在创建一个在线零售店。那个属于一个类别的物品。当我尝试提交带有选定类别的项目时，它将不会保存

我试了好几个小时来解决但却无法理解。有谁知道问题是什么？

错误是

ActiveRecord::AssociationTypeMismatch in ItemsController#create
Category(#70298375791060) expected, got String(#70298372605800)

  def create
    @item = current_user.items.build(item_params)
    if @item.save
      redirect_to @item
      flash[:success] = "You have created a new item"

项目表格

<h1>Create New item</h1>

<div class="container">
  <div class=“row”>
    <div class="col-md-6 col-md-offset-3">
      <div class="panel panel-primary">
        <div class="panel-body">
          <%= simple_form_for @item, html: { multipart: true } do |f| %>
            <%= f.input :image%>
            <%= f.collection_select :category, Category.order(:name), :id, :name, include_blank: true, :prompt => "Select One Category" %>
            <%= f.input :title%>
            <%= f.input :price %>
            <%= f.input :description %>
            <%= f.button :submit, "Create new item", class: "btn btn-primary" %>
          <% end %>
        </div>
      </div>    
    </div>
  </div>
</div>

项目控制器

class ItemsController < ApplicationController
  before_action :correct_user_edit,   only: [:edit, :update, :destroy]

  def index
    @item = @user.items.paginate(page: params[:page])
  end

  def new
    @item = Item.new
  end

  def home
    @items = Item.paginate(page: params[:page])
  end

  def edit
    @item = Item.find(params[:id])
    @user = User.find(params[:id])
  end

  def show
    @item = Item.find(params[:id])
  end

  def update
    @item = Item.find(params[:id])
    if @item.update(item_params)
       redirect_to @item
       flash[:success] = 'Item was successfully updated.'
    else
      render "edit"
    end
  end

  def create
    @item = current_user.items.build(item_params)
    if @item.save
      redirect_to @item
      flash[:success] = "You have created a new item"
    else
      flash[:danger] = "Your item didn't save"
      render "new"
    end
  end

  def destroy
    Item.find(params[:id]).destroy
    flash[:success] = "Item deleted"
    redirect_to users_url
  end

  private

    def item_params
      params.require(:item).permit(:title, :category, :price, :description, :image)
    end

    #Check to see if user can edit item.
    def correct_user_edit
      if @item = current_user.items.find_by(id: params[:id])
      else
        flash[:danger] = "You can't edit that item"
        redirect_to root_url if @item.nil?
      end
    end

end

项目模型

class Item < ActiveRecord::Base
    belongs_to :user
    belongs_to :category
    validates :category, presence: true
    validates :title, presence: true, length: { maximum: 30 } 
    validates :price, presence: true
    validates :description, presence: true, length: { maximum: 2000 }
    validates :user_id, presence: true
    has_attached_file :image, styles: { large: "600x600", medium: "250x250", thumb:"100x100#"}
    validates_attachment_content_type :image, content_type: /\Aimage\/.*\Z/
end

类别模型

class Category < ActiveRecord::Base
    has_ancestry
    has_many :items
end

Answer 1

ItemsController #create中的ActiveRecord :: AssociationTypeMismatch 类别（＃70298375791060）预期，得到字符串（＃70298372605800）

这一行

<%= f.collection_select :category, Category.order(:name), :id, :name, include_blank: true, :prompt => "Select One Category" %>

应该是

<%= f.collection_select :category_id, Category.order(:name), :id, :name, include_blank: true, :prompt => "Select One Category" %>

并且还改变了item_params

def item_params
  params.require(:item).permit(:title, :category_id, :price, :description, :image)
end

未定义的方法`category_id＆＃39;对于项目：0x007fdf43bebed0

category_id表中应该有items列。运行以下命令，该命令将创建一个迁移文件，以便将category_id添加到items。

rails g migration add_category_id_to_items category_id:integer

和run rake db:migrate

我建议你在进一步阅读之前阅读这些Guides。

Answer 2

而不是<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" tools:context="gsie.beezlink.OpportunityActivity"> <Button android:layout_width= "match_parent" android:layout_height="wrap_content" android:text="@string/posterbtn" android:background="#008000" android:id="@+id/posterbtn" android:gravity="center" android:layout_alignParentBottom="true" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/cinteretxt" android:textSize="20sp" android:textStyle="bold" android:id="@+id/cinteretxt" android:layout_alignParentTop="true" /> <Spinner android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/cinteretspin" android:layout_below="@+id/cinteretxt" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/optitretxt" android:textSize="20sp" android:textStyle="bold" android:id="@+id/optitretxt" android:layout_below="@+id/cinteretspin" /> <EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/optitreedt" android:layout_below="@+id/optitretxt" android:hint="@string/hintoptitre" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/optxt" android:textSize="20sp" android:textStyle="bold" android:id="@+id/optxt" android:layout_below="@+id/optitreedt" /> <EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/opedt" android:hint="@string/hintpost" android:layout_below="@+id/optxt" /> </RelativeLayout>，您应该传递category param。

ItemsController #creart中的AssociationTypeMismatch

2 个答案: