需要通过 Rails has_many 带回中间模型和终端模型的信息

Question

我有以下型号：

学校.rb

class School < ActiveRecord::Base

  has_many :offers
  has_many :players, :through => :offers

  has_many :teammembers, :class_name => 'Offer', :conditions => ["on_roster = \'t\'"]
  has_many :teamplayers, :through => :teammembers, :source => :player

播放器.rb

class Player < ActiveRecord::Base

  has_many :offers, :dependent => :destroy

  scope :sr, lambda { 
    where("(players.year = ? and players.redshirt = 't') or (players.year = ? and players.redshirt = 'f')", (Time.now + 8.months - 5.years).year, (Time.now + 8.months - 4.years).year)

}

offer.rb

class Offer < ActiveRecord::Base
    belongs_to :school
    belongs_to :player

    validates_uniqueness_of :school_id, :scope => [:player_id]

然后在我的学校控制器中

schools_controller.rb

def show
  @school = School.find(params[:id], :include => [{:offers => :player}])
  @seniors = @school.teamplayers.sr

我的问题是我需要显示 offer 模型中与 School 和 Player 之间的关系相关联的字段。目前，我正在视图中执行附加查询以获取此字段。

学校/show.haml.html

- @srpg.each do |player|
  = Offer.find_by_school_id_and_player_id(@school.id, player.id).status

显然这会导致 N+1 问题，但我似乎无法找到一种方法将 offer.status 和 player.* 都带回同一记录中。

Answer 1

改为使用优惠：

# in model
class Offer
  belongs_to :player
  scope :of_seniors, includes(:player).where('player.kind = "senior"')
end

# in controller
@seniors_offers = @school.offers.of_seniors

# in view
- for offer in @seniors_offers
  = offer.player.name
  = offer.status
- end