CODEWITHSUNDEEP
sqlruby-on-railspostgresqlactiverecord
Callmeed
Callmeed

Reputation: 5002

How to get only highest score/record in a game's daily leaderboard with Rails 4 + Postgres

I have a game with a Rails 4 + Postgres backend on Heroku. Our daily leaderboard shows the highest 100 scores in the game. We have a User model and a Score model (User has_many :scores).

It works as expected like this: 

class Score < ActiveRecord::Base
  belongs_to :user

  def self.daily_leaders
    where(['created_at > ? and created_at < ?', Time.now.beginning_of_day, Time.now.end_of_day]).order("points DESC").limit(100)
  end
end

But we'd now like to change this so it only shows the highest score for each user. I have tried every combination of additional .select() .distinct and .pluck ActiveRecord methods I can, but I'm always getting PG errors.

What would be the proper way to get JUST each user's highest score for just today?

Upvotes: 0

Views: 349

Answers (1)

usha
usha

Reputation: 29359

class Score < ActiveRecord::Base
  belongs_to :user

  def self.user_max_scores
    where('date(created_at) = ?', Date.today).select('user_id, max(points) as max_points').group(:user_id)
  end
end

Upvotes: 2

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