title: How to obtain data from a table that has been joined
body: <p>I have two tables <code>items</code> and <code>games</code>.</p>
  
  <pre><code>@app.route('/collection/&lt;username&gt;/&lt;int:page&gt;/&lt;platform&gt;/&lt;path:path&gt;')    
  def collection(username, page=1, platform='DMG', path=None):
      # first I get the user by his username
      user = User.query.filter_by(username=username).first()
      # then I get all items form the user and related games
      items = user.items.join(Game)
      # until now it works perfectly fine        
      # now I would like to obtain all titles from the joined table games
      game_titles = items.filter(Game.title).all()
      # but unfortunately I get only an empty list
  </code></pre>
  
  <p>What is missing?</p>
  
  <p>Here my models:</p>
  
  <pre><code>class Game(db.Model):
      __tablename__ = 'games'
      id = db.Column(db.Integer, primary_key=True)
      title = db.Column(db.String(64), index=True)
      publisher = db.Column(db.String(32), index=True)
      region = db.Column(db.String(3), index=True)
      code_platform = db.Column(db.String(3), index=True)
      code_identifier = db.Column(db.String(4), index=True)
      code_region = db.Column(db.String(3), index=True)
      code_revision = db.Column(db.String(1))
      code = db.Column(db.String(16), index=True, unique=True)
      year = db.Column(db.Integer)
  
      user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
      items = db.relationship('Item', backref='game', lazy='dynamic')
  
      def __repr__(self):
          return '&lt;Game %r&gt;' % (self.title)
  
  
  class Item(db.Model):
      __tablename__ = 'items'
      id = db.Column(db.Integer, primary_key=True)
      code = db.Column(db.String(8), index=True)
      cart = db.Column(db.Boolean)
      box = db.Column(db.Boolean)
      manual = db.Column(db.Boolean)
  
      user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
      game_id = db.Column(db.Integer, db.ForeignKey('game.id'))
  
      def __repr__(self):
         return '&lt;Collection %r&gt;' % (self.user_id)
  </code></pre>