Django Rest Framework - get foreignkey id from value when inserting - django

Question

I can not get a clear answer after two days of searching for what must probably be one of the most common things to do with a DRF:
I have the following model:
class ProcessedStockAmounts(models.Model):
prodName = models.ForeignKey(Productlist, on_delete=models.CASCADE, blank=False, unique=False)
amount = models.CharField(unique=False, max_length=255)
time = models.ForeignKey(StockTakingTimes, on_delete=models.CASCADE, blank=False, unique=False, default=1)
def __str__(self):
return str(self.prodName)
And I am returning a JSON object via my API that looks like this:
[{'prodName': 'SV1', 'amount': '1111111', 'time' : 1}]
When I insert my prodName with a value it has no problem, but obviously my user will not know the prodName ID and only the prod name. So when I try to insert the above I get the following error:
ValueError: Cannot assign "'SV1'": "ProcessedStockAmounts.prodName" must be a "Productlist" instance.
This was the closest I got to an answer and when I do the following it actually inserts:
p = ProcessedStockAmounts(amount='33', prodName = Productlist.objects.get(productid = 'SV1'), time = StockTakingTimes.objects.get(times='06:00'))
p.save()
but giving data this way is obviously defeating the purpose.
My serializer looks like the following:
class TestSerializer(serializers.ModelSerializer):
# time = serializers.SlugRelatedField(read_only=True, slug_field='time')
prodName = serializers.CharField()
# prodName = serializers.SlugRelatedField(read_only=True, slug_field='prodName')
class Meta:
model = ProcessedStockAmounts
fields = ('prodName','amount','time')
With my view:
class InsertMultiProcessedStock(APIView):
def post(self, request, format='json'):
serializer = TestSerializer(data = request.data, many=True)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
else:
return Response(serializer.errors)
Productlist model:
class Productlist(models.Model):
productid = models.CharField(unique=True, max_length=20) # Field name made lowercase.
proddescription = models.CharField(db_column='prodDescription', max_length=255, blank=True, null=True) # Field name made lowercase.
packaging = models.ForeignKey(Packaging, on_delete=models.CASCADE, blank=True, null=True)
unitweight = models.FloatField(db_column='unitWeight', blank=True, null=True)
def __str__(self):
return self.productid

Answer 1

This would have been easier if you had the related model. But the commented-out slugrelatedfield is the way you should do it, using the actual field name:
prodName = serializers.SlugRelatedField(read_only=False, slug_field='productid')

Answer 2

Your serializer is wrong， You must use relationship serializer.
prodName = ProductlistSerializer(many = False)
But I found Your model defintion is very confusing