text 将列添加到现有表

Posted 2021-05-02

// Suppose we have a Post model with body:integer and title:string columns. Generate a migration to add a user_id column to the posts table.

$ rails g migration AddUserIdToPosts

// Update the migration file, so the $ rake db:migrate command will add the user_id column to the posts table.

class AddUserIdToPosts < ActiveRecord::Migration
  def change
    add_column :posts, :user_id, :integer
  end
end