django ORM query not working properly?

Question

Django

Hi
i have a sql query

SELECT stock_id, consignment_id, SUM(qty), SUM(cost) 
    FROM warehouse_regсonsignmentproduct
    Where product_id = '1'
    Group BY  stock_id, consignment_id
    Having SUM(qty) > 0

I tried to rewrite it with Django query:

regСonsignmentProduct.objects
        .filter(product='1')
        .order_by('period')
        .values('stock', 'consignment')
        .annotate(total_qty=Sum('qty'), total_cost=Sum('cost'))
        .filter(total_qty__gt=0)

But it doesn't return the correct result. Maybe someone knows where my mistake is?

Thanks!