Integrate djongo (Mongo ORM) into Django Rest Framework - mongodb

Question

Actually I am developping a POC on which we want an app which has a REST API and discuss with MongoDB in Python.
For this we found several techs, such as Django-rest-framework for the API side and djongo for the ORM side. Nevertheless, I scan lots of tutos on how to implement djongo ORM in DRF, no way there is nothing BUT apparently it's possible, can someone confirm?
My main problem is my POC does absolutely not work, indeed, in used djongo models in my DRF Serializers but it does not work at all, I dont understand, can someone figure it out whats going on?:
models.py:
from djongo import models
class Channel(models.Model):
sourceId = models.IntegerField(default=-1)
usageId = models.IntegerField(default=0)
channelId = models.IntegerField(default=0)
cabinetId = models.IntegerField(default=0)
zoneId = models.IntegerField(default=0)
class Product(models.Model):
dateCreation = models.DateTimeField(auto_now=True)
dateUpdate = models.DateTimeField(auto_now=True)
name = models.CharField(max_length=50, default="Unknown product name")
channels = models.EmbeddedModelField(
model_container=Channel,
)
objects = models.DjongoManager()
views.py:
from django.http import HttpResponse, JsonResponse
from django.views.decorators.csrf import csrf_exempt
from rest_framework.parsers import JSONParser
from Api.models import Product
from Api.serializers import ProductSerializer
#csrf_exempt
def ProductList(aRequest):
"""
#brief List all products, or create a new product.
"""
if aRequest.method == 'GET':
wProducts = Product.objects.all()
wSerializer = ProductSerializer(wProducts, many=True)
return JsonResponse(wSerializer.data, safe=False)
elif aRequest.method == 'POST':
data = JSONParser().parse(aRequest)
wSerializer = ProductSerializer(data=data)
if wSerializer.is_valid():
wSerializer.save()
return JsonResponse(wSerializer.data, status=201)
return JsonResponse(wSerializer.errors, status=400)
#csrf_exempt
def ProductDetail(aRequest, pk):
"""
#brief Retrieve, update or delete a product.
"""
try:
wProducts = Product.objects.get(pk=pk)
except Product.DoesNotExist:
return HttpResponse(status=404)
if aRequest.method == 'GET':
wSerializer = ProductSerializer(wProducts)
return JsonResponse(wSerializer.data)
elif aRequest.method == 'PUT':
data = JSONParser().parse(aRequest)
wSerializer = ProductSerializer(wProducts, data=data)
if wSerializer.is_valid():
wSerializer.save()
return JsonResponse(wSerializer.data)
return JsonResponse(wSerializer.errors, status=400)
elif aRequest.method == 'DELETE':
Product.delete()
return HttpResponse(status=204)
serializers.py:
from rest_framework import serializers
from Api.models import Product, Channel
class ChannelSerializer(serializers.ModelSerializer):
class Meta:
model = Channel
fields = ('sourceId', 'usageId', 'channelId', 'cabinetId', 'zoneId')
def create(self, validated_data):
wChannel = Channel.objects.create(**validated_data)
return wChannel
class ProductSerializer(serializers.ModelSerializer):
channels = ChannelSerializer(many=True)
class Meta:
model = Product
fields = ('dateCreation', 'dateUpdate', 'name', 'channels')
def create(self, validated_data):
wChannels = validated_data.pop("channels")
wProduct = Product.objects.create(**validated_data)
for wChannel in wChannels:
Channel.objects.create(product=wProduct, **wChannel)
return wProduct
When I run my server with this POST request:
{
"dateCreation": "2018-07-20 12:00:00.000",
"dateUpdate": "2018-07-20 12:00:00.000",
"name": "post_test_channel_1",
"channels": [{
"sourceId": -1,
"usageId": 100,
"channelId": 0,
"cabinetId": 0,
"zoneId": 1
}]
}
I obtain that stacktrace:
Internal Server Error: /products/
Traceback (most recent call last):
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/core/handlers/exception.py", line 35, in inner
response = get_response(request)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/core/handlers/base.py", line 128, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/core/handlers/base.py", line 126, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
return view_func(*args, **kwargs)
File "/home/soulasb/projects/POC/PocEms/Api/views.py", line 25, in ProductList
wSerializer.save()
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/rest_framework/serializers.py", line 214, in save
self.instance = self.create(validated_data)
File "/home/soulasb/projects/POC/PocEms/Api/serializers.py", line 29, in create
wProduct = Product.objects.create(**validated_data)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/query.py", line 417, in create
obj.save(force_insert=True, using=self.db)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/base.py", line 729, in save
force_update=force_update, update_fields=update_fields)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/base.py", line 759, in save_base
updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/base.py", line 842, in _save_table
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/base.py", line 880, in _do_insert
using=using, raw=raw)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/query.py", line 1125, in _insert
return query.get_compiler(using=using).execute_sql(return_id)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1284, in execute_sql
for sql, params in self.as_sql():
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1237, in as_sql
for obj in self.query.objs
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1237, in <listcomp>
for obj in self.query.objs
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1236, in <listcomp>
[self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1176, in prepare_value
value = field.get_db_prep_save(value, connection=self.connection)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 767, in get_db_prep_save
return self.get_db_prep_value(value, connection=connection, prepared=False)
File "/home/soulasb/projects/POC/venv-app/lib/python3.6/site-packages/djongo/models/fields.py", line 461, in get_db_prep_value
model=Model
ValueError: Value: None must be instance of Model: <class 'django.db.models.base.Model'>

Answer 1

This usually happens when you have added an EmbeddedModelField in your model and not passing an object to this field while creating an entry to this model.
I didnt find an option to add an EmbeddedModelField with null=True option.
Hope this helps someone

Answer 2

It could be the ENFORCE_SCHEMA set to true in settings.py. Maybe change it to "ENFORCE_SCHEMA: false".