title: What is the correct way to use refresh_from_db in Django?
body: <p>I'm using Django 1.8, Mezzanine, Cartridge, and I use Postgresql as the database.  </p>
  
  <p>I've updated the <code>num_in_stock</code> directly from the database.  The quantities are all correct in the database but not on my website.  I know the solution is <a href="https://docs.djangoproject.com/en/1.8/ref/models/instances/#refreshing-objects-from-database" rel="nofollow">here</a>, but I don't know what to do with that.  I really need it spelled out for me.  </p>
  
  <p>How exactly would you use this in Cartridge to refresh the <code>num_in_stock</code>?</p>