Django rest 框架组由

Question

I want to group by my data on the basis of ingredient_id so that it does not repeat in response, as you can see am querying on the basis of ingredient_id which is a foreign key so it can be repeated in the database. But I want all the ingredient data to be once and then the supply_chain information around it.

model.py

class SupplyChainStops(models.Model):
    ingredient = models.ForeignKey(Ingredients, null=True, on_delete=models.CASCADE)
    stop_name = models.CharField(max_length=1024, null=True, blank=True)
    stop_longitude = models.CharField(max_length=500, null=True, blank=True)
    stop_latitude = models.CharField(max_length=500, null=True, blank=True)

    def __str__(self):
        return f'{self.stop_name}'

query

@api_view(['GET'])
def supply_chain_response_detail(request, id):
    ingredient_detail = SupplyChainStops.objects.filter(ingredient_id=id).all()
    serializer = SupplyChainStopsSerializer(ingredient_detail, many=True)
    return Response(serializer.data)

Serializer

class IngredientSerializer(serializers.ModelSerializer):
    ingredient_category = IngredientCategorySerializer()
    supplier = SuppliersSerializer()
    origin = OriginSerializer()
    allergies = AllergiesSerializer(many=True)

    class Meta:
        model = Ingredients
        fields = '__all__'


class SupplyChainStopsSerializer(serializers.ModelSerializer):
    ingredient = IngredientSerializer(many=False)

    class Meta:
        model = SupplyChainStops
        fields = '__all__'

Answer 1

You can make a distinct query with a positional argument. Here is a new version of your view.

@api_view(['GET'])
def supply_chain_response_detail(request, id):
    ingredient_detail = SupplyChainStops.objects.filter(ingredient_id=id).distinct(
                                               "ingredient_id")
    serializer = SupplyChainStopsSerializer(ingredient_detail, many=True)
    return Response(serializer.data)

NOTE: Positional argument is only supported in PostgreSQL