ruby-on-rails - 向模型添加新列

Question

尝试将名字和姓氏添加到现有模型用户

首先这样做:

rails g migration first_name_to_users first_name:string

然后这样做:

rails g migration last_name_to_users last_name:string

显然运行了 rake db:migrate 结果是这样的:

== FirstNameToUsers: migrating =============================================== == FirstNameToUsers: migrated (0.0000s) ======================================

== LastNameToUsers: migrating ================================================ == LastNameToUsers: migrated (0.0000s) =======================================

但它并没有出现在表格中!

如果我进入 Rails 控制台并运行 User.column_names，我得到这个:

=> ["id", "email", "encrypted_password", "reset_password_token", "reset_password_sent_at", "remember_created_at", "sign_in_count", "current_sign_in_at", "last_sign_in_at", "current_sign_in_ip", "last_sign_in_ip", "created_at", "updated_at"] 

如果有人问它是否出现在 db/migrate 文件夹中，答案是肯定的。

这是姓氏:

class LastNameToUsers < ActiveRecord::Migration
    def change
    end
end

那么......为什么它没有出现在表格中？

Answer 1

在一个迁移文件中执行此操作，

rails g migration add_columns_to_users

然后在使用上述命令生成的迁移文件中执行此操作:-

class AddColumnsToUsers < ActiveRecord::Migration
  def change
    add_column :users, :first_name, :string
    add_column :users, :last_name, :string
  end
end