title: Current Date in SQLAlchemy ORM relationship
body: <p>I'm trying to configure a relationship between two objects based on the current date. Say I have a <code>Person</code> object and a relationship to a bunch of <code>Event</code> objects. If the <code>Event</code> object holds a <code>DateTime</code> (<code>start</code>) on it, I want to make a relationship to all of today's events.</p>
  
  <p>So far I have:</p>
  
  <pre><code>class Person:
      id = Column(Integer, primary_key=True)
      todays_events = relationship('Event', primaryjoin='and_(Person.id == Event.person_id, cast(Event.start, Date) == "2016-04-23"')
  </code></pre>
  
  <p>This works but I can't find what I need to replace the date string with "2016-04-23" to get the equivalent of <code>CURDATE()</code>.</p>
  
  <p>Does anyone know what I'm looking for?</p>
  
  <p>Thanks.</p>