Is there a way to annotate this django object computer property?

Question

I have an django Model named Payment that I want to filter by a computed property.

class Payment(Model):
   ...other fields
   terms = PositiveIntegerField(help_text='days')
   issued_date = DateField()

then I have this property to calcutate the payment_date

@property
def payment(self):
    return self.issued_date + datetime.timedelta(days=self.terms)

I tried to annotate it with something like this:

Payment.objects.annotate(due_date=ExpressionWrapper(F('issued_date') + F('terms'), output_field=DateField()))

but unfortunately it's not working. Any help on this is greatly appreciated.

Answer 1

Actually this works:

Payment.objects.annotate(due_date=ExpressionWrapper(F('issued_date') + F('terms'), output_field=DateField()))

The problem was that due_date already exist as a property and changing this to a different name fixed the error.

Payment.objects.annotate(date_due=...rest of the expression here)