如何优化此ActiveRecord查询？

我仍然每天都在学习ruby，rails和ActiveRecord。现在，我正在通过一个新的小型应用程序学习SQL，但问题是我的应用程序主视图当前每页刷新约2000个查询，oouuuppps。

因此，既然我知道我的数据库中已包含所有必需的信息，并且可以正确显示它们，那么该是时候对其进行优化了，但是我不知道该从何说起。

这些是我的模特协会

class League < ActiveRecord::Base
  belongs_to :user
  has_many :league_teams
  has_many :teams, :through => :league_teams
end


class Team < ActiveRecord::Base
  has_many :gameweeks
  has_many :league_teams
  has_many :leagues, :through => :league_teams
end


class Gameweek < ActiveRecord::Base
  belongs_to :team
  has_and_belongs_to_many :players
  has_and_belongs_to_many :substitutes, class_name: "Player", join_table: "gameweeks_substitutes"
  belongs_to :captain, class_name: "Player"
  belongs_to :vice_captain, class_name: "Player"
end


class Player < ActiveRecord::Base
  serialize :event_explain
  serialize :fixtures
  serialize :fixture_history
  has_many :gameweeks, class_name: "captain"
  has_many :gameweeks, class_name: "vice_captain"
  has_and_belongs_to_many :gameweeks
  has_many :player_fixtures
end

所以这是我的控制器：

@league = League.includes(teams: [{gameweeks: [{players: :player_fixtures} , :captain]}]).find_by(fpl_id:params[:fpl_id])
@teams = @league.teams
@defense_widget_leaderboard = @league.position_based_leaderboard_stats(@teams, ['Defender', 'Goalkeeper'])

这是我的联赛模型中的一种方法：

  def position_based_leaderboard_stats(teams,positions_array)
    leaderboard = []

    teams.each do |team|
      position_points = 0
      gameweeks = team.gameweeks

      gameweeks.each do |gameweek|
        defense = gameweek.players.where(type_name:positions_array)

        defense.each do |player|
          player.player_fixtures.where(gw_number: gameweek.number).each do |p|
            position_points += p.points
          end
        end
      end
      leaderboard << [team.team_name,position_points]
    end
    return leaderboard.sort_by {|team| team[1]}.reverse
  end

我有4种方法，它们看起来与上述方法大致相同。每个查询都执行300到600个查询。

就我而言，这是N + 1查询的典型情况。我试图减少@league中的include，但是它使我从2000个查询下降到1800个查询。

我看着group_by，joins并sum但我不能让它工作。

我最接近工作的是

players = PlayerFixture.group("player_id").sum(:points)

然后我可以在其中进行查询，players[player.id]但是无论如何都不会给我正确的结果，因为它没有考虑Gameweeks> Players> Player_fixtures关系。

如何减少正在执行的查询数量？我在freenode上继续#RubyOnRails，人们告诉我可以在1个查询中完成，但不会指向我任何方向或对我有帮助...

谢谢