Single database for multiple shops

Use ActsAsTenant as Multi-tenancy for shops

See below files:
- app/controllers/concern/multi_tenancy.rb
- app/models/application_record.rb
- app/models/shop.rb

An initializer can be created to control option in ActsAsTenant.
config/initializers/acts_as_tenant.rb
require 'acts_as_tenant/sidekiq'
ActsAsTenant.configure do |config|
  config.require_tenant = false # true
end

more details: https://github.com/ErwinM/acts_as_tenant

app/controllers/base_oqs_controller.rb

@@ -1,5 +1,5 @@
 class BaseOqsController < ActionController::Base
-  include LoginVerification
+  include LoginVerification, MultiTenancy
   layout "OQS"
 
   before_action :check_user