query_object_model.rb

# /app/models/item.rb
class Item < ActiveRecord::Base
  ...

  def self.search(query_string, opts = {})
    # Build the query
    search_body = Jbuilder.encode do |json|
      json.query do
        json.filtered do
          json.query do
            json.multi_match do
              json.fields %i(description title)
              json.query query_string
            end
          end
          json.filter do
            json.bool do
              json.set! :must, [
                {
                  :term => {
                    :approved => true
                  }
                }
              ]
            end
          end
        end
      end
    end
    
    # Execute the query
    results = MyApp::Elasticsearch.client.search \
      :body  => search_body,
      :index => :my_index,
      :type  => :items
      
    # Format the results
    Hashie::Mash.new(results["hits"]).hits
  end
end