Rails与模型和迁移的关联 [英] Rails association with models and migration

问题描述

无法理解Rails与模型的关联如何工作.这是一个简单的问题:

Can't understand how Rails association with models works. Here is simple question:

有两个表

产品

id|   name  | status
1 | Tube    | 0
2 | Pillar  | 1
3 | Book    | 0
4 | Gum     | 1
5 | Tumbler | 2

状态

status | name
0      | Unavailable
1      | In stock
2      | Discounted

在型号和控制器上使用〜相同的名称.

With ~ same names for models and controllers.

我不需要在每个新产品的状态表中创建新行.我想在erb中显示状态名称.我应该在模型和迁移文件中写些什么(例如，对于属于归属_，has_one或has_many ...)?

I don't what to create new row in statuses table on every new product. And i want to show status name in erb. What should i write in models and in migration file (for example for which belong_to, has_one or has_many...)?

推荐答案

对于简单的一对多关联，产品应为belongs_to :status，状态应为has_many :products，并且您无需设置商品的状态产品.在erb中，您将使用<%= @product.status.name %>.要设置这些迁移，请create_table :products do |t| t.string :name; t.integer :status_id; end和create_table :statuses do |t| t.string :name; end

Product should belongs_to :status and Status should has_many :products for a simple one-to-many association, and you aren't required to set a status for a product. In erb you'd use <%= @product.status.name %>. To set up those migrations, create_table :products do |t| t.string :name; t.integer :status_id; end and create_table :statuses do |t| t.string :name; end

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