Django REST - PUT and PATCH create new object instead of updating - django-rest-framework

Question

I'm creating a basic Django REST API that will work with a catalogue of products. I have to check every time a non-registered user GETS a product and add to the current value. And the GET and DELETE work perfectly fine. The problem is that whenever I want to update a product, a new Product is created instead.
I have 2 models:
class Brand(models.Model):
brand_name = models.CharField(max_length=500)
def __str__(self):
return self.brand_name
class Product(models.Model):
sku = models.PositiveIntegerField(primary_key=True, validators=[MaxValueValidator(999999999999999)])
product_name = models.CharField(max_length=500)
product_price = models.DecimalField( max_digits=50, decimal_places=2)
product_brand = models.ForeignKey(Brand, on_delete=models.CASCADE)
times_searched_anonymous = models.PositiveIntegerField(default=0)
def __str__ (self):
return self.product_name + ' (' + self.product_brand.brand_name + ')' + ' - $' + str(self.product_price)
These are my serializers:
class ProductSerializer(serializers.ModelSerializer):
class Meta:
model = Product
fields = [
"sku",
"product_name",
"product_price",
"product_brand",
"times_searched_anonymous"
]
class BrandSerializer(serializers.ModelSerializer):
class Meta:
model = Brand
fields = [
"brand_name",
"pk",
]
And this is the view I have:
class ProductDetail(generics.RetrieveUpdateDestroyAPIView):
"""
Retrieve, update or delete a product instance.
"""
permission_classes = [permissions.IsAuthenticatedOrReadOnly]
def get_object(self, pk):
try:
return Product.objects.get(pk=pk)
except Product.DoesNotExist:
raise Http404
def get(self, request, pk, format=None):
product = self.get_object(pk)
serializer = ProductSerializer(product)
if not request.user.is_authenticated:
data2 = {'times_searched_anonymous': product.times_searched_anonymous + 1}
serializer2 = ProductSerializer(product, data=data2, partial=True)
if serializer2.is_valid():
serializer2.save()
return Response(serializer2.data)
return Response(serializer.data)
def put(self, request, pk, format=None):
product = self.get_object(pk)
serializer = ProductSerializer(product, data=request.data, partial=True)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
def patch(self, request, pk):
product = self.get_object(pk)
serializer = ProductSerializer(product, data=request.data,
partial=True) # set partial=True to update a data partially
if serializer.is_valid():
serializer.save()
return JsonResponse(code=201, data=serializer.data)
return JsonResponse(code=400, data="wrong parameters")
def delete(self, request, pk, format=None):
product = self.get_object(pk)
product.delete()
return Response(status=status.HTTP_204_NO_CONTENT)
Thougths?

Answer 1

in put method change line
serializer = ProductSerializer(product, data=request.data, partial=True)
to be serializer = ProductSerializer(instance=product, data=request.data, partial=False)
also in patch method change line
serializer = ProductSerializer(product, data=request.data, partial=True)
to be
serializer = ProductSerializer(instance=product, data=request.data, partial=False)