why is this rails association loading individually after an eager load?
- by codeman73
I'm trying to avoid the N+1 queries problem with eager loading, but it's not working. The associated models are still being loaded individually.
Here are the relevant ActiveRecords and their relationships:
class Player < ActiveRecord::Base
has_one :tableau
end
Class Tableau < ActiveRecord::Base
belongs_to :player
has_many :tableau_cards
has_many :deck_cards, :through => :tableau_cards
end
Class TableauCard < ActiveRecord::Base
belongs_to :tableau
belongs_to :deck_card, :include => :card
end
class DeckCard < ActiveRecord::Base
belongs_to :card
has_many :tableaus, :through => :tableau_cards
end
class Card < ActiveRecord::Base
has_many :deck_cards
end
and the query I'm using is inside this method of Player:
def tableau_contains(card_id)
self.tableau.tableau_cards = TableauCard.find :all, :include => [ {:deck_card => (:card)}], :conditions => ['tableau_cards.tableau_id = ?', self.tableau.id]
contains = false
for tableau_card in self.tableau.tableau_cards
# my logic here, looking at attributes of the Card model, with
# tableau_card.deck_card.card;
# individual loads of related Card models related to tableau_card are done here
end
return contains
end
Does it have to do with scope? This tableau_contains method is down a few method calls in a larger loop, where I originally tried doing the eager loading because there are several places where these same objects are looped through and examined. Then I eventually tried the code as it is above, with the load just before the loop, and I'm still seeing the individual SELECT queries for Card inside the tableau_cards loop in the log. I can see the eager-loading query with the IN clause just before the tableau_cards loop as well.
EDIT: additional info below with the larger, outer loop
Here's the larger loop. It is inside an observer on after_save
def after_save(pa)
@game = Game.find(turn.game_id, :include => :goals)
@game.players = Player.find :all, :include => [ {:tableau => (:tableau_cards)}, :player_goals ], :conditions => ['players.game_id =?', @game.id]
for player in @game.players
player.tableau.tableau_cards = TableauCard.find :all, :include => [ {:deck_card => (:card)}], :conditions => ['tableau_cards.tableau_id = ?', player.tableau.id]
if(player.tableau_contains(card))
...
end
end
end
