Rails include with multiple tables - ruby-on-rails-3.1

Question

Please anyone help me:
Using Rails I developed an application.
My models look like this:
class Score < ActiveRecord::Base
belongs_to :song
belongs_to :user
end
class Song < ActiveRecord::Base
has_one :gsong
has_many :scores
end
class Gsong < ActiveRecord::Base
belongs_to :song
end
class user < ActiveRecord::Base
has_many :scores
end
And my ScoresController:
class scoresController < ApplicationController
def index
id = current_user.id
#scores = score.where(:user_id => id)
render :json => {
:scores => #scores.as_json(:include => {:gsong => { :include => { :song => { :only => [:title, :album]}}, :only => [:artwork]}}, :only => [:song_id, :score]),
}
end
It's working fine functionally, But it's making too many queries in the database like below:
score Load (0.1ms) SELECT `scores`.* FROM `scores` WHERE `scores`.`user_id` = 3
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs` WHERE `gsongs`.`id` = 8 LIMIT 1
Song Load (0.1ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` = 8 LIMIT 1
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs` WHERE `gsongs`.`id` = 2 LIMIT 1
Song Load (0.1ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` = 2 LIMIT 1
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs` WHERE `gsongs`.`id` = 1 LIMIT 1
Song Load (0.1ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` = 1 LIMIT 1
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs` WHERE `gsongs`.`id` = 11 LIMIT 1
Song Load (0.1ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` = 11 LIMIT 1
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs` WHERE `gsongs`.`id` = 12 LIMIT 1
Song Load (0.1ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` = 12 LIMIT 1
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs` WHERE `gsongs`.`id` = 23 LIMIT 1
Song Load (0.1ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` = 23 LIMIT 1
How can I fetch all this data with single or two queries like:
Gsong Load (0.1ms) SELECT `gsongs`.* FROM `gsongs`
Song Load (0.3ms) SELECT `songs`.* FROM `songs` WHERE `songs`.`id` IN (8,2,1,11,12,23)

Answer 1

I would look into using ActiveModel serializers. I think you'll find it will make complex JSON like this a breeze
There's a great Screencast on it at
http://railscasts.com/episodes/409-active-model-serializers