Group results with multiple uses of annotate()

[Adam Starrh]

I've got the following function in a manager which seems to work well, annotating data and grouping results by "variety name":

def by_variety_and_date(self, start_date, end_date):
    return self.model.objects.filter(
        date__range=(start_date, end_date)
    ).values(
        "variety__name"
    ).annotate(
        total_kgs=Sum('qty_applied'),
        total_profit=Sum('profit'),
        grand_total_cogs=Sum('total_cogs'),
        total_sales=Sum('value'),
    ).order_by('-total_kgs')

However, I would like to add a piece of information like so:

def by_variety_and_date(self, start_date, end_date):
    return self.model.objects.filter(
        date__range=(start_date, end_date)
    ).values(
        "variety__name"
    ).annotate(
        total_kgs=Sum('qty_applied'),
        total_profit=Sum('profit'),
        grand_total_cogs=Sum('total_cogs'),
        total_sales=Sum('value'),
    ).annotate(
        final_margin=Case(
        When(total_sales=0, then=0),
        default=(Sum(F('profit')) / Sum(F('value')))*100
        )
    ).order_by('-total_kgs')

In this case, the grouping doesn't work, and each item is returned separately. Essentially `.values().annotate()` works, but `.values().annotate().annotate()` seems to break. 

I've also tried `.annotate().annotate().values()` as well to no avail.

Is this the intended behavior? Am I missing a piece of instruction? 

[Adam Starrh]

OK I got this to work. The second annotate needs to go at the end, so that the order is as follows: .filter().values().annotate().order_by().annotate()