ruby-on-rails - レールを使用したgooglemaps api

Question

だから私はgooglemaps APIを使っていて、地図上でデータベース内の店舗を検索できるようにしたいと思っています。geokit-rails gem も使用しています。ただし、form_for(@song) で次のエラーが発生します。

First argument in form cannot contain nil or be empty

query_controller:

class QueriesController < ApplicationController
  def index
    @store = Store.find(:all)
  end
end

クエリ#インデックス:

 = form_for(@store) do |f|                                                
    .field                                                                  
  %f.label>                                                         
  \%> br                                                              
  \#(f.check_box :active)                                                    
  %br/            

スキーマ.rb:

     ActiveRecord::Schema.define(version: 0) do

      create_table "queries", :options => 'ENGINE=MyISAM', force: true do |t|
        t.string   "uuid",           limit: 250
        t.float    "lat",                        null: false
        t.float    "lng",                        null: false
        t.float    "execution_time",             null: false
        t.integer  "gps_accuracy",               null: false
        t.integer  "mode",           limit: 1,   null: false
        t.datetime "created_at",                 null: false
      end

      create_table "stores", :options => 'ENGINE=MyISAM', force: true do |t|
        t.string  "name",          limit: 250, default: "",   null: false
        t.string  "subname",       limit: 250, default: "",   null: false
        t.string  "phone",         limit: 250, default: "",   null: false
        t.string  "address",       limit: 250, default: "",   null: false
        t.string  "city",          limit: 100, default: "",   null: false
        t.string  "province",      limit: 50,  default: "",   null: false
        t.string  "postalCode",    limit: 25,  default: "",   null: false
        t.float   "lat",                                      null: false
        t.float   "lng",                                      null: false
      t.integer  "mode",           limit: 1,   null: false
    t.datetime "created_at",                 null: false
  end



     create_table "stores", :options => 'ENGINE=MyISAM', force: true do |t|
        t.string  "name",          limit: 250, default: "",   null: false
        t.string  "subname",       limit: 250, default: "",   null: false
        t.string  "phone",         limit: 250, default: "",   null: false
        t.string  "address",       limit: 250, default: "",   null: false
        t.string  "city",          limit: 100, default: "",   null: false
        t.string  "province",      limit: 50,  default: "",   null: false
        t.string  "postalCode",    limit: 25,  default: "",   null: false
        t.float   "lat",                                      null: false
        t.float   "lng",                                      null: false
        t.integer "store_type",    limit: 1
        t.boolean "active",                    default: true, null: false
      end

    end

store.rb

class Store < ActiveRecord::Base                                                                                                                              

end