Used in medium controller article

schema.rb

  create_table "passports", force: :cascade do |t|
    t.integer "number"
    t.integer "user_id", null: false
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.index ["user_id"], name: "index_passports_on_user_id"
  end

  create_table "users", force: :cascade do |t|
    t.string "name"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end