更新DB /手动更新模型后迁移？ [英] Update db/migrate after manually updating models?

问题描述

例如，我有这个模型：

class Product < ActiveRecord::Base
  attr_accessible :name, :order
end

后来，当我做了耙分贝：迁移它创造了这个 DB /迁移/ 20120825132038_create_products.rb

class CreateProducts < ActiveRecord::Migration
  def change
    create_table :products do |t|
      t.integer :order
      t.string :name

      t.timestamps
    end
  end
end

不过，这一切happend因为我使用轨生成产品订单：整数名称：字符串

现在后，我去的产品型号和手动更改它：

Now after i go to Product model and changes it manually to:

class Product < ActiveRecord::Base
  attr_accessible :name, :order, :category_id

  validates :name, uniqueness: true
  belongs_to :category
end

我怎么能自动更新的 DB /迁移/ 20120825132038_create_products.rb 的更新吗？

推荐答案

当你运行耙分贝：迁移，它的没有创建 DB /迁移/ 20120825132038_create_products.rb 。当你跑了，移民文件的创建

When you ran rake db:migrate, it did not create db/migrate/20120825132038_create_products.rb. That migration file was created when you ran

rails generate Product order:integer name:string

attr_accessible 已无关，与迁移数据库。

attr_accessible has nothing to do with migrating your database.

我强烈建议你阅读Rails的手册上的 迁移 的，以及作为上一节的 质量分配 的，其中讨论了 attr_accessible 。

I strongly recommend you read the Rails Guide on Migrations, as well as the section on Mass Assignment which discusses attr_accessible.

要生成的新的迁移文件中的（因为在你的问题中提到的，有一个已经被处理了previous 耙分贝：迁移命令你所提到的运行）的，执行

To generate a new migration file (since the one mentioned in your Question has already been processed by the previous rake db:migrate command you mentioned running), run

rails g migration AddCategoryIdToProduct category_id:integer

这应该生成与内容的新移民一样

This should generate a new migration with contents like

class AddCategoryIdToProduct < ActiveRecord::Migration
  def change
    add_column :products, :category_id, :integer
  end
end

运行耙分贝：迁移再现在处理这个迁移文件，添加新的 CATEGORY_ID 整数列到你产品表。

Running rake db:migrate again now will process this migration file, adding the new category_id integer column to your products table.

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