Identifying Rails Query Results

Question

I have three models User, Game and Point where a user gets points for playing games. What I'm trying to do is display the users with the most points for the most popular games in a view.

I used this question to determine the most popular games. So I now have this scope in Game.rb:

scope :most_popular_games,
  select("games.id, name, count(points.id) AS points_count").
  joins(:points).
  group("games.id").
  order("points_count DESC").
  limit(5)

In my controller, I have this:

@most_popular_games = Game.most_popular_games

My models:

Models

class Point < ActiveRecord::Base
  belongs_to :game
  belongs_to :user
end

class Game< ActiveRecord::Base
  has_many :points
end

class User < ActiveRecord::Base
  # no relationship for points or games
end

class GameRank < ActiveRecord::Base
  belongs_to :game
  belongs_to :user
end

However, what I can't figure out what to do is create a way to now total the points per user for each of these games and make it so I identify each game differently, so I segment them out on the view (ie show the results separately for each game).

I tried adding this in the code, but I wasn't sure of the best way to make each game's results be identifiable in the view:

@most_popular_games.each do |most_popular_game|
  most_points_for_popular_game = GameRank.where("game_id =?", most_popular_game.id).order('total_points desc').limit(10)
end

My question is basically how do I reuse the results for "most_points_for_popular_game" - which is the users with the most points for a given game - for each of the five games (@most_popular_games = five results)?

maybe try to give the model relationship to see, so it can be done without SQL. What are the relationship? One user plays one game one time, or two users can play one game or one user can play one game only once? — Zippie, Mar 12 '13 at 23:37

score 0 · Accepted Answer · answered Mar 13 '13 at 04:24

Totally ignoring N+1 queries and additional markup:

Add the :game_ranks relationship to Game:

class Game
  has_many :game_ranks
end

Add a scope to GameRank:

class GameRank
  scope :top, order('total_points desc').limit(10)
end

(I'm assuming a total_points column on GameRank based on your example)

In your view:

<% @most_popular_games.each do |game| %>
   <%= game.name %>
   <% game.game_ranks.top.each do |rank| %>
      <%= rank.user.name %>,<%= rank.total_points %>
   <% end %>
<% end %>

Identifying Rails Query Results

1 Answers1