Question

我刚刚向我的博客介绍了类别，我已经在帖子上做了友好的工作。所以我决定将它整合到类别中。问题是我一直收到错误Couldn't find Category with 'id'=test-2以及ActiveRecord::RecordNotFound in CategoriesController#show请理解我已经尝试实施我在这里找到的许多解决方案，但我无法让它工作

class CategoriesController < ApplicationController

  before_action :find_category, only: [:show, :update, :edit, :destroy]

   def index
    @categories = Category.all
   end

  def new 
    @category = Category.new
  end

  def create
    @category = Category.new(category_params)
    if @category.save
      flash[:success] = "Category created"
      redirect_to categories_path

    else
      render 'new'
    end
  end

  def edit

  end

  def update
    if @category.update(category_params)
      flash[:success]="name was successfully updated"
      redirect_to category_path(@category)
    else
      render 'edit'
    end
  end

  def show

  end

  private
  def category_params
    params.require(:category).permit(:name)
  end

  def find_category
    @category = Category.friendly.find(params[:id])
  end

end

现在奇怪的问题是当我进入rails控制台并尝试更新slug时，它显示如下：

Category.find_each(&:save)
  Category Load (0.3ms)  SELECT  "categories".* FROM "categories"  ORDER BY "categories"."id" ASC LIMIT 1000
   (0.1ms)  begin transaction
  Category Exists (0.1ms)  SELECT  1 AS one FROM "categories" WHERE ("categories"."id" != 1) AND "categories"."slug" = ? LIMIT 1  [["slug", "sports"]]

上面我们可以看到它说slug，sports ..这很棒，但是当我做一个发现时...... slug似乎是零如下：

2.3.0 :058 > c = Category.find(1)
  Category Load (0.8ms)  SELECT  "categories".* FROM "categories" WHERE "categories"."id" = ? LIMIT 1  [["id", 1]]
 => #<Category id: 1, name: "sports", created_at: "2016-07-28 15:12:13", updated_at: "2016-07-28 15:12:13", slug: nil>

我还尝试通过试图找到实际的slug来确认这一点：

2.3.0 :051 > Category.find(1).slug
  Category Load (0.2ms)  SELECT  "categories".* FROM "categories" WHERE "categories"."id" = ? LIMIT 1  [["id", 1]]
 => nil

slu p似乎是零。

最后，以防它是相关的...这是我的show.html.erb

<h1 align="center"><%= "Category: " + @category.name %></h1>
<div align = "center">
  <% if user_signed_in? %>
     <div id="admin_links">
       <%= link_to "Edit", edit_category_path(@category) %>
       <%= link_to "Delete", category_path(@category), method: :delete, data: {confirm: "Are you sure you want to delete?"} %>
     </div>
   <% end %>

   <%= link_to "Edit Category name", edit_category_path(@category) %>

</div>

这里是category.rb

class Category < ActiveRecord::Base
  extend FriendlyId
  friendly_id :name, use: :slugged
  has_many :category_posts
  has_many :posts, through: :category_posts


  def should_generate_new_friendly_id?
    slug.blank? || name_changed?
  end
end

当我在控制台中Category.first(5)时，这就是结果

Category Load (0.3ms)  SELECT  "categories".* FROM "categories"  ORDER BY "categories"."id" ASC LIMIT 5
 => [#<Category id: 1, name: "sports", created_at: "2016-07-28 15:12:13", updated_at: "2016-07-28 15:12:13", slug: nil>,
    #<Category id: 2, name: "Nerd", created_at: "2016-07-28 17:33:35", updated_at: "2016-07-28 17:33:35", slug: nil>,
    #<Category id: 3, name: "testing", created_at: "2016-07-28 17:38:22", updated_at: "2016-07-28 17:39:23", slug: nil>,
    #<Category id: 4, name: "test 2", created_at: "2016-07-28 19:10:18", updated_at: "2016-07-28 19:10:18", slug: nil>,
    #<Category id: 5, name: "books", created_at: "2016-07-28 19:29:18", updated_at: "2016-07-28 19:29:18", slug: nil>

Answer 1

在您的Category模型中，您拥有attr_accessor :slug，它将覆盖用于数据库中字段的setter方法。这意味着不会保存slug字段。

从模型中删除attr_accessor :slug +再次重新创建实例以重新生成slu。

Answer 2

使用friendly_id时，您需要使用其方法替换您的查找程序。而不是

@category = Category.find(params[:id])

使用

@category = Category.friendly.find(params[:id])

关于未填写的slu ,,请确保在Category模型中有类似的内容：

class Category < ActiveRecord::Base
    extend FriendlyId
    friendly_id :name, use: :slugged

    # ...
end

friendly_id slugs继续返回nil导致ActiveRecord错误

2 个答案: