将djongo(Mongo-ORM)集成到Django Rest框架中

Question

实际上我正在开发一个POC，我们想要一个具有REST API的应用程序，并在Python中与MongoDB讨论。

为此，我们找到了几种技术，例如API端的Djang-rest-framework和ORM端的djongo。尽管如此，我浏览了很多关于如何在DRF中实现djongo-ORM的教程，不可能什么都没有，但显然这是可能的，有人能证实吗？

我的主要问题是我的POC在我的DRF序列化程序中使用的djongo模型中绝对不起作用，但它根本不起作用。我不明白，有人能弄清楚发生了什么吗？：

型号.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()

视图.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)

序列化程序.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

当我用这个POST请求运行服务器时：

{
"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
}]
}

我获得了堆叠种族：

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

当您在模型中添加了EmbeddedModelField，并且在创建该模型的条目时没有将对象传递到此字段时，通常会发生这种情况。我找不到添加具有null=True选项的EmbeddedModelField的选项。

希望这能帮助

Answer 2

它可能是settings.py中设置为true的ENFORCE_SCHEMA；ENFORCE_SCHEMA:false"；。