python - How to update multiple records at once (bulk update) in django API

Question

I need to update categories in many Article in one request.

In ArticleViewSet I have:

def get_serializer_class(self):
    if self.action in ['partial_update', 'update']:
        return ArticlePostSerializer
    return ArticleSerializer

So ArticlePostSerializer need to be changed.

This is my serializers code:

class ArticleShortCategorySerializer(serializers.ModelSerializer):

    class Meta:
        model = Category
        fields = 'id', 'name'


class ArticleSerializer(serializers.ModelSerializer):
    categories = serializers.SerializerMethodField()

    def get_categories(self, obj):
        return ArticleShortCategorySerializer(obj.categories, many=True).data

    class Meta:
        model = Article
        read_only_fields = 'id'
        fields = ('categories', 'text') + read_only_fields


class ArticlePostSerializer(serializers.ModelSerializer):

    class Meta:
        model = Article
        fields = 'id', 'categories', 'text'

I tried to add:

class ArticlePostListSerializer(serializers.ListSerializer):

and

class Meta:
    list_serializer_class = ArticlePostListSerializer

But it doen't work. How to change this code to do multiple update. My json request

{
    [id: 90, categories: [10,12,14]],
    [id: 93, categories: [10,12,14]],
    [id: 95, categories: [10,12,14]]
}

Answer 1

Here is sample of CreateMixins OR UpdateMixins you requested.

======================= VIEW ================================

class OrderCreate(mixins.CreateModelMixin,viewsets.GenericViewSet):
    pagination_class = None

    def get_queryset(self):
        return []

    def get_serializer_class(self):
        return serializers.OrderSerializer

======================= Serializer =============================

class OrderDetailSerializer(serializers.ModelSerializer):
    class Meta:
        model = crm_models.OrderDetail
        fields = (
                'product',
                'quantity',
                'rate_per_unit',
                'order_quantity'
                )

class OrderSerializer(serializers.ModelSerializer):
    order_details = OrderDetailSerializer(many = True)
    class Meta:
        model = crm_models.OrderMaster
        fields = (
                'order',
                'invoice_number',
                'client',
                'beat_check',
                'target_customer',
                'order_editor_client_employee',
                'order_marked',
                'order_saved',
                'edit_marked',
                'edit_saved',
                'adhoc',
                'order_details'
                )

    def create(self, validated_data,*args,**kwargs):
        ordersdetails_data = validated_data.pop('order_details')
        user = None
        request = self.context.get("request")
        if request and hasattr(request, "user"):
            user = request.user
            validated_data['client'] = user.client
            validated_data['order_editor_client_employee'] = user
            validated_data['adhoc'] = validated_data['adhoc'] if 'adhoc' in validated_data else False

        orderObj = super(OrderSerializer, self).create(validated_data,*args,**kwargs)
        orderdetails = []
        for details in ordersdetails_data:
            orderdetails.append(crm_models.OrderDetail(
                product= details['product'],
                quantity = details['quantity'],
                rate_per_unit = details['rate_per_unit'],
                order_quantity = details['order_quantity'],
                order = orderObj
            ))
        crm_models.OrderDetail.objects.bulk_create(orderdetails)
        return orderObj

In Update view function name would be changed to update, you can find more documentation http://www.django-rest-framework.org/api-guide/generic-views/#createmodelmixin