class User < ActiveRecord::Base
  has_many :places
  has_many :rooms, :through => :places

  named_scope :inside, lambda {|room|
    { :conditions => { 'place.room_id' => room }} # doesn't work
  }

# ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: place.room_id: SELECT * FROM "users"     WHERE ("place"."room_id" = 1)
end