如何在Rails中创建类别 [英] How to create Categories in Rails

问题描述

我尝试添加类别到我的Rails应用程序，但不知道如何做这个。

我有很多Pins用户能够在这些引脚上分配类别。
ASSIGN 不能创建，修改或删除类别，只需为其定位选择一个。
意思是，当用户上传一个pin，他可以从下拉列表中选择一个类别。

然后，另一个用户可以从菜单中选择一个类别，并且只列出此类别中的引脚。

我该如何做？从哪里开始？

谢谢

解决方案

不想在应用程式中管理类别，只要在应用程式中的表格和类别选项中新增类别栏位：

 <％= f.select：category，['Box'，'Cover'，'Poster']，：prompt => '选择一个'％> 
  

其次，如果要在应用程序中管理类别，表为它。所以你可以从生成你的模型开始：

  rails g模型类别
  pre> 
 
 
它将在您的应用程序目录中添加模型和迁移。为迁移添加内容：
  class CreateCategories< ActiveRecord :: Migration 
 def change 
 create_table：categories do | t | 
 t.string：name 
 t.text：description 
 ##你可以根据你的要求添加更多的东西
 t.timestamps 
 end 
 end 
 end 
  
定义类别& Pin模型添加验证为： -  
 在类别模型：
 has_many：pins 
 
 In Pin型号：
 belongs_to：category 
 validates：category，presence：true 
  
按类别控制器和表单创建一些类别（我不认为，我需要告诉你的东西，你能够自己做）
 
 
 
在你的pin uploading form add this select： -  
 <％= f.select：category，Category.all，：prompt => ; 选择一个％> 
  
希望，这将有所帮助。
 
i'm trying to Add Categories to my Rails app, but don't quite know how to do this.

I have many Pins(Images) and want the user to be able to assign a category on those Pins.
ASSIGN not create, edit, or delete a Category, just selecting one for their Pin.
Meaning that, When a user uploads a pin, he can choose from a dropdown list a Category.

Then, another user can choose from the Menu a Category, and ONLY the Pins in this Category will be listed.

How do i do this? Where to start ?

Thank you
解决方案
First If you don't want to manage categories in your application, then you can simply add a category field in your table and category select in your application :
<%= f.select :category, [ 'Box', 'Cover', 'Poster' ], :prompt => 'Select One' %>
Second, If you want to manage categories in your application, than you have to maintain a separate model and table for it. So you can start with generating your model:
rails g model category
it will add model and migration in your application directory. Add stuff to your migration:
class CreateCategories < ActiveRecord::Migration
  def change
    create_table :categories do |t|
      t.string :name
      t.text :description
      ## you can add more stuff as per your requirements 
      t.timestamps
    end
  end
end
Define associations in category & Pin model add validation for this :-
In Category Model:
  has_many :pins

In Pin Model :
  belongs_to :category
  validates :category, presence: true
Create some categories by categories controller and form (I don't think, I need to tell you that stuff, you are able to do it yourself)

In your pin uploading form add this select :-
<%= f.select :category, Category.all, :prompt => "Select One" %>
Hope, It will help.

                        
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