title: How to set the default value for existing entries when adding a new column?
body: <p>I have a model in my Django app that requires a new <code>BooleanField</code>column to be added. This column should never be null - instead, I'd like all the existing entries to set this field to <code>False</code>.</p>
  
  <p>How do I do that? If I just add the new field and set <code>default = False</code>, it'll cause an <code>OperationalError: no such column</code> error.</p>