title: Django version of a database trigger?
body: <p>I have two tables: Cameras &amp; Timestamp,
  Timestamp has a foreign key to cameraID.
  Both camera and timestamp have a 'State' field.
  Each timestamp entry has a camera and a current state.
  I want to update the Camera.State value when Timestamp.State for that camera is updated. In SQL I know how to do this with a database trigger. But I am not sure how to achieve this in Django</p>