Question

我通过

创建了一个rails模型

script/generate model Customer name:string address:string city:string state:string zip:integer [...]

我用5000个客户填充数据库并开始构建我的应用程序。现在我意识到我的模型没有规范化：我经常在同一个地址有多个客户！如果我希望按地址执行某些操作，例如邮件，则会导致问题。我想要的是Address模型，Customer模型和Mailing模型。

是否有轨道方式来规范现有模型，将其拆分为两个模型？或者我应该编写一个脚本来规范化现有数据，然后相应地生成新模型吗？

Answer 1

您询问了迁移的样子。我没有在评论回复中填写此内容，而是为您创建了一个新答案。

script/generate model address customer_id:integer address:string city:string state:string zip:integer

class CreateAddresses < ActiveRecord::Migration
  def self.up
    create_table :addresses do |t|
      t.integer :customer_id
      t.string :address
      t.string :city
      t.string :state
      t.integer :zip_code
      t.timestamps
    end

    # move customer address fields to address table
    Customer.all.each do |c|
      Address.create({
        :customer_id => c.id,
        :address => c.address,
        :city => c.city,
        :state => c.state,
        :zip => c.zip
      })
    end

    # you'll have to write your own merge script here
    # use execute("your sql goes here...") if you can't do it with ActiveRecord methods

    # remove old customer address columns
    remove_columns(:customers, :address, :city, :state, :zip)

  end

  def self.down

    # here you will define the reverse of the self.up method

    # re-add the address columns to the user table

    # repopulate the customer table with data from the address table

    drop_table :addresses
  end
end

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Answer 2

我不知道内置的Rails方式以编程方式拆分模型。您需要编写一个新的Address模型和数据库更新迁移，以便切换所有内容。

您的模型可能看起来像这样：

class Person < ActiveRecord::Base
  has_many :addresses
end

class Address < ActiveRecord::Base
  belongs_to :person
end

规范化rails中的数据

2 个答案:

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