How to make QuerySet JSON serializable? - json

Question

I have a problem with creating a new object in my Rest Framework.
As much I as understand, when I tried to overwrite item's field so it could have all the items that are in my database. I thought, that this would work, and it showed me the working page and I could choose an item. But when I tried to post it to create a new object, it said "Object of type 'Item' is not JSON serializable"
I was trying to figure it out, how to convert Item.objects.all() into JSON data. But nothing helped me. I understand, that this isn't really hard to do, but I can't figure it out on my own.
So I ask for your help, how to solve this problem?
Here's my serializer
from rest_framework import serializers
from items.models import OrderItem, Item
class OrderItemSerializer(serializers.ModelSerializer):
item = serializers.ChoiceField(choices=Item.objects.all())
class Meta:
model = OrderItem
fields = ('item', 'size', 'quantity', 'id')

Answer 1

from rest_framework import serializers
from items.models import OrderItem, Item
class OrderItemSerializer(serializers.ModelSerializer):
item = serializers.SerializerMethodField()
class Meta:
model = OrderItem
fields = ('item', 'size', 'quantity', 'id')
def get_item (self, obj):
# in value list name all fields u want or empty for defaults
return Item.objects.all().values_list('pk', flat=True)
...
and inside the create method (post in Serializer)
...
def create(self, validated_data):
req = self.context.get('request')
items = req.data.get('item')
if items:
[OrderItem.item.add(
oneitem) for oneitem in items]