class AddUserIdentityTable < ActiveRecord::Migration[4.2] def change create_table :user_identities do |t| t.belongs_to :user, index: true t.string :provider, null: false t.string :uid, null: false t.timestamps null: true end add_index :user_identities, %i(provider uid), unique: true add_index :user_identities, %i(user_id provider), unique: true end end