Mongoid - two fields inverses of the same foreign

Question

I'm trying to get the following Mongoid relationships to work, but the game field of each team is an empty array. Is this not a valid relational model? Do I need to split up games, i.e. home_games and away_games?

class Team
  include Mongoid::Document

  has_many :games, :autosave => true

end

class Game
  include Mongoid::Document

  belongs_to :home_team, :class_name => "Team", :inverse_of => :games
  belongs_to :away_team, :class_name => "Team", :inverse_of => :games

end

Answer 1

I dont think so there is a straight way to do this, may be you workaround by

class Team
  include Mongoid::Document

  has_many :home_played, :class_name => 'Game' , :inverse_of => :home_team
  has_many :away_played, :class_name => 'Game' , :inverse_of => :away_team


 def games
    Game.any_of({:home_team_id => self.id},{:away_team_id => self.id})
 end

end

class Game
  include Mongoid::Document

  belongs_to :home_team, :class_name => "Team", :inverse_of => :home_played
  belongs_to :away_team, :class_name => "Team", :inverse_of => :away_played

end

so now you can use it like

g = Game.new
+--------------------------+-------+--------------------------+--------------+--------------+
| _id                      | _type | _id                      | home_team_id | away_team_id |
+--------------------------+-------+--------------------------+--------------+--------------+
| 4ec76f70b356f8031f000001 |       | 4ec76f70b356f8031f000001 |              |              |
+--------------------------+-------+--------------------------+--------------+--------------+
1 row in set
>> t=Team.new
+--------------------------+-------+--------------------------+
| _id                      | _type | _id                      |
+--------------------------+-------+--------------------------+
| 4ec76f75b356f8031f000002 |       | 4ec76f75b356f8031f000002 |
+--------------------------+-------+--------------------------+
1 row in set
>> t.save
=> true
g.home_team = t
+--------------------------+-------+--------------------------+
| _id                      | _type | _id                      |
+--------------------------+-------+--------------------------+
| 4ec76f75b356f8031f000002 |       | 4ec76f75b356f8031f000002 |
+--------------------------+-------+--------------------------+
1 row in set
>> g.save
=> true

and

>> Team.first.home_played
+--------------------------+-------+--------------------------+--------------------------+--------------+
| _id                      | _type | _id                      | home_team_id             | away_team_id |
+--------------------------+-------+--------------------------+--------------------------+--------------+
| 4ec76f70b356f8031f000001 |       | 4ec76f70b356f8031f000001 | 4ec76f75b356f8031f000002 |              |
+--------------------------+-------+--------------------------+--------------------------+--------------+
1 row in set
>> Game.first.home_team
+--------------------------+-------+--------------------------+
| _id                      | _type | _id                      |
+--------------------------+-------+--------------------------+
| 4ec76f75b356f8031f000002 |       | 4ec76f75b356f8031f000002 |
+--------------------------+-------+--------------------------+

abd you can get the total count by

>> Team.first.games

Hope this helps