subject_tweet.rb

class SubjectTweet
  include DataMapper::Resource
  
  property :subject_id, Integer, :key => true
  property :tweet_id,   String,  :key => true
  
  property :created_at, DateTime, :index => true
  
  def self.default_storage_name; 'subjects_tweet' end
  
  def find_or_create_for_tweet_and_subject tweet, subject
    SubjectTweet.first(:tweet_id => tweet.id, :subject_id => subject.id) ||
    SubjectTweet.create(
      :tweet_id   => tweet.id, 
      :subject_id => subject.id,
      :created_at => tweet.created_at)
  end
  
  def self.tweets params
    Tweet.get all(params).map{|one| one.tweet_id }
  end
end