django-queryset

I have this code: q = MyModel.objects.order_by('-value1').annotate( res=ExpressionWrapper( (F('value1') / F('value2')), output_field=FloatField()), ) for i in q: print(i.value1, i.value2, i.res) So, the output will be: 5 10 0.0 1 2 0.0 But I need 5 10 0.5 1 2 0.5 Wy F() rounded the result? How not to do this? Thanks! The result you are expecting is really easy to achieve with a raw query and really, I mean really hard to achieve with pure django. from django.db.models import FloatField, ExpressionWrapper, F template = '%(function)s(%(expressions)s AS FLOAT)' fv1 = Func(F('value1'), function=

I have several Models and want to return a queryset of all the Models belonging to a User, I'm wondering if its possible to return one Queryset from multiple Models? I am assuming that you mean you would like to return a single queryset of all the objects belonging to the user from each model. Do you need a queryset or just an iterable? AFAIK, heterogeneous qs's are not possible. However, you could easily return a list, a chained iterator (itertools) or a generator to do what you want. This assumes that the models referencing the user are known ahead of time. Assuming default related_name,

I am in Python 2.7 and Django 1.7.1 with django-restframework I have an API that returns me some specific values taken fron the Database, it uses a Custom Serializer like this: class InventarioSerializer(serializers.ModelSerializer): item = serializers.RelatedField(source='producto.item') ubicacion = serializers.RelatedField(source='ubicacion.nombre') class Meta: model = Inventario fields = ('epc','item','cantidad','ubicacion') My API's view is called this way: class ItemEnInventarioViewSet(InventarioListModelMixin, viewsets.ModelViewSet): serializer_class = InventarioSerializer renderer

I have the following : class Product(models.Model): name = models.CharField(max_length=255) class Action(models.Model): product = models.ForeignKey(Product) created_at = models.DateTimeField(auto_now_add=True) I would like to retrieve the 10 most recent actions ordered by created_at DESC with distinct products. The following is close to the result but still misses the ordering: Action.objects.all().order_by('product_id').distinct('product_id')[:10] Your solution seems like it's trying to do too much. It will also result in 2 separate SQL queries. This would work fine and with only a single

I'm working with Django and I need to do a queryset using two inner joins. I have three models A, B, and C and I want to do a query like the following in psql: select DISTINCT a from A inner join B on B.a_id = A.id inner join C on C.b_id = B.id; Models: (only included relevant fields) class A(models.Model): id = models.IntegerField(primary_key=True) class B(models.Model): id = models.IntegerField(primary_key=True) a = models.ForeignKey(A, null=True, blank=True,on_delete=models.SET_NULL) class C(models.Model): b = models.ForeignKey(B, null=True, on_delete=models.SET_NULL) So everything in C

I have a very simple view as follows def simple_view(request): documents = request.user.document_set.all() return render(request, 'simple.html', {'documents': documents}) To test the above view in my test case i have the following method which errors out. Class SomeTestCase(TestCase): # ... def test_simple_view(self): # ... some other checks docset = self.resonse.context['documents'] self.assertTrue(self.user.document_set.all() == docset) # This line raises an error # ... The error i get is AssertionError: False is not true . I have tried printing both the querysets and both are absolutely

I'm just wondering if there is any example I could take from others on the topic. I have a page within Django which uses filters, in order to perform searches. At the moment I'm doing a simple check for the GET parameters and adding a .filter() to a queryset accordingly: if color: query.filter(color=color) This feels a bit like an ugly way to do, and I've been a bit stuck wondering how I could make it more dynamic. Any ideas? Try this: ALLOWED = ('color', 'size', 'model') kwargs = dict( (key, value) for key, value in request.GET.items() if key in ALLOWED ) query.filter(**kwargs) This will