Annotate duration/integer -> MySql error

[KenWhitesell]

It’s possible that you may want to try adding an extra set of parens around that expression.

e.g.

@plopidou

    login_frequency=ExpressionWrapper(
       ( (Now() - F('created_datetime')) / F('login_count')  ),
        output_field=models.DurationField()
    ),