deviseのconfirmableを使うには対象modelで宣言 devise :confirmable 必要なカラム class AddConfirmableToUser < ActiveRecord::Migration[5.0] def change add_column :users, :confirmation_token, :string add_column :users, :confirmed_at, :datetime add_column :users, :confirmation_sent_at, :datetime add_column :users, :unconfirmed_email, :string # Only if using reconfirmable add_index :users, :confirmation_token, unique: tr