Question

I have 3 models.

class Team < ActiveRecord::Base
  ...
  has_many :seasons_teams, :dependent => :destroy                          
  has_many :seasons, :through => :seasons_teams
  has_and_belongs_to_many :players
  ...
end

class Season < ActiveRecord::Base
  ...
  has_many :players_seasons, :dependent => :destroy
  has_many :players, :through => :players_seasons
  has_many :seasons_teams, :dependent => :destroy
  has_many :teams, :through => :seasons_teams
  ...
end

class Player < ActiveRecord::Base
  ...
  has_many :players_seasons, :dependent => :destroy
  has_many :seasons, :through => :players_seasons
  has_and_belongs_to_many :teams
  ...
end

There will be validations such that any given player can have at most one team for each season.

I am looking for an efficient way to get a players team for any given season, i.e.:

@player.team(@season)

Thanks!

Answer 1

I think something like this ought to work:

@player.teams.joins( :seasons ).where( :season_id => @season.id ).first

To get the nice concise syntax you’re looking for you would use it in a scope, e.g.:

class Team < ActiveRecord::Base
  scope :for_season, lambda do |season|
    joins( :seasons ).where( :season_id => season.id )
  end
  # ...
end

class Player < ActiveRecord::Base
  # ...

  def team season
    teams.for_season( season ).first
  end
end

@player.team @season
# => #<Team:0x...>