models.rb

class Place < ActiveRecord::Base
  attr_accessible :address, :city, :name, :description
  has_many :meetings
end

Class Meeting < ActiveRecord::Base
  attr_accessible :start_at, :place_id, :title, :end_at

  belongs_to :place
  has_many :participations
  has_many :players, :through => :participations

end

class Participation < ActiveRecord::Base
  attr_accessible :meeting_id, :player_id
end

class Player < ActiveRecord::Base
  attr_accessible :id, :city, :first_name, :gear, :last_name, :email,
:password, :password_confirmation

  has_many :participations
  has_many :meetings, :through => :participations
end