I wrote a many-to-many field for my model but when I try to write an updated view with generic-view-set don't append the new obj just replace it,how can I write to append the new obj to list, my model:
class Portfolio(models.Model):
name = models.CharField(max_length=50, blank=False, null=True, default='portfolio')
user = models.ForeignKey('accounts.User', on_delete=models.DO_NOTHING, related_name='investor')
assets = models.ManyToManyField(Assets, related_name='portfolio_assets')
def __str__(self):
return self.name
Serializer
class PortfolioUpdateSerializer(serializers.ModelSerializer):
class Meta:
model = Portfolio
fields = ['id', 'name']
View
class PortfolioAssetsUpdate(mixins.UpdateModelMixin, viewsets.GenericViewSet
):
queryset = Portfolio.objects.all()
serializer_class = PortfolioAssetsUpdateSerializer
def put(self, request, pk):
return self.update(request, pk)
Now my problem is when I update my portfolio, a new object replaces to old one, I need to append new to old,I really don't have any idea
Related
i'm working on a django project and i got this error (Cannot assign "'11'": "Product.category" must be a "CategoryProduct" instance.) anyone here can help me please.
Model:
class Product(models.Model):
name = models.CharField("Nombre", max_length=150)
category = models.ForeignKey(CategoryProduct, on_delete=models.SET_NULL, null=True, related_name='category')
def __str__(self):
return self.name
View:
class ProductCreateView(CreateView):
model = Product
form_class = ProductForm
success_url = '/adminpanel/products/'
def post(self, request, *args, **kwargs):
form = self.get_form()
category = CategoryProduct.objects.get(id=request.POST['category'])
if form.is_valid():
product = form.save(commit=False)
product.category = category
product.save()
Form:
class ProductForm(forms.ModelForm):
name = forms.CharField(max_length=150, label="Nombre")
category = forms.ChoiceField(choices=[(obj.id, obj.name) for obj in CategoryProduct.objects.all()], label="Categoría")
class Meta:
model = Product
fields = ['name', 'category']
You can let Django's ModelForm do its work, this will create a ModelChoiceField [Django-doc], which is where the system gets stuck: it tries to assign the primary key to category, but that should be a ProductCategory object, so you can let Django handle this with:
class ProductForm(forms.ModelForm):
class Meta:
model = Product
fields = ['name', 'category']
If you want to specify a different label, you can use the verbose_name=… [Django-doc] from the model field, or specify this in the labels options [Django-doc] of the Meta of the ProductForm. So you can specify Categoria with:
class Product(models.Model):
name = models.CharField('Nombre', max_length=150)
category = models.ForeignKey(
CategoryProduct,
on_delete=models.SET_NULL,
null=True,
related_name='products',
verbose_name='Categoria'
)
def __str__(self):
return self.name
then the CreateView can just use its boilerplate logic:
class ProductCreateView(CreateView):
model = Product
form_class = ProductForm
success_url = '/adminpanel/products/'
Note: The related_name=… parameter [Django-doc]
is the name of the relation in reverse, so from the Category model to the Product
model in this case. Therefore it (often) makes not much sense to name it the
same as the forward relation. You thus might want to consider renaming the category relation to products.
I am trying to insert data on one modal class on destroying another model class. My First model class:
class UserDevice(models.Model):
type = models.ForeignKey(
'Device',
on_delete=models.CASCADE
)
hardware_serial = models.CharField(max_length=255)
created_at = models.DateTimeField(auto_now_add=True)
class NewDevice(models.Model):
type = models.ForeignKey(
'Device',
on_delete = models.CASCADE
)
hardware_serial = models.CharField(max_length=255)
created_at = models.DateTimeField(auto_now_add=True)
Whenever I will destroy the UserDevice I want to the same device should be added in NewDevice
My serializer class is :
class UserDeviceSerializer(serializers.ModelSerializer):
class Meta:
model = models.UserSensorDevice
fields = '__all__'
read_only_fields = ['id','created_at']
def create(self, validated_data):
app_id = models.UserDevice.objects.filter(sensor_code= validated_data.get('hardware_serial', None)).first()
if app_id:
msg = _('Application ID is already registered')
raise serializers.ValidationError(msg, code='authorization')
else :
return models.UserDevice.objects.create(**validated_data)
class NewDeviceSerializer(serializers.ModelSerializer):
class Meta:
model = models.NewDevice
fields = '__all__'
read_only_fields = ['id','created_at']
My view class:
class UserSensorRemoveDevice(generics.DestroyAPIView):
authentication_classes = (authentication.TokenAuthentication,)
permission_classes = (permissions.IsAuthenticated,)
queryset = models.UserDevice.objects.all()
serializer_class = serializers.UserDeviceSerializer
What I have tried to override UserDevice destroy. But somehow its not working:
def destroy(self, validated_data):
return models.NewDevice.objects.create(type = validated_data.get('type', None),hardware_serial = validated_data.get('hardware_serial', None))
Any help will be highly appreciated. Thanks in advance.
You can override UserDevice.delete() method
class UserDevice(models.Model):
...
def delete(self, *args, **kwargs):
NewDevice.objects.create(type=self.type, hardware_serial=self.hardware_serial)
super().delete(*args, **kwargs)
in can just override your model UserDevice delete function
def delete(self, using=None, keep_parents=False):
#add new NewDevice instance
super().delete(using, keep_parents,*args,**kwargs)
I have just followed a small tutorial using DRF, but I can't figure how to like my model to his user when POSTing a new object
this is my model :
# Create your models here.
class Project(models.Model):
# project title
title = models.CharField(max_length=255, null=False)
# subtitle
subtitle = models.CharField(max_length=255, null=False)
#######
user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
and so my serializer
class ProjectSerializer(serializers.ModelSerializer):
class Meta:
model = Project
fields = ("id", "title", "subtitle", "user_id")
so, now in the view I have access to the current_user with this :
request.user
class ListProjectsView(generics.ListCreateAPIView):
authentication_classes = [authentication.TokenAuthentication]
queryset = Project.objects.all()
serializer_class = ProjectSerializer
def list(self, request):
queryset = Project.objects.filter(user_id=request.user.id)
serializer = ProjectSerializer(queryset, many=True)
return Response(serializer.data)
[...]
def create(self, request, pk = None):
return super(ListProjectsView, self).create(request, pk = None)
I suppose there is a way to passe the request.user is the create in order to allow my Project.user_id to be filled ?
Whatever I'm doing, I can't manage to set the user, and i get the
django.db.utils.IntegrityError: null value in column "user_id" violates not-null constraint error
Any idea?
Thanks!
Try to override with following method. Everytime PUT/PATCH/CREATE operation is performed following method is called. This is the good way to pass the current user.
def perform_create(self, serializer):
serializer.save(user = self.request.user)
class Project(models.Model):
# project title
title = models.CharField(max_length=255, null=False)
# subtitle
subtitle = models.CharField(max_length=255, null=False)
user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
okay so you have FK user but try to access it with the user_id = request.user.id
Just call
queryset = Project.objects.filter(user=request.user)
queryset = Project.objects.filter (user_id=request.user.id)
if you want to match the id you should put two __
like so user__id = request.user.id but I dont see any sence making it.
The "Brand" object is foreign key of "company",they are ManytoMany relationship,and Brand object exists the field "company_Group"
the models are as follows:
class Brand(models.Model):
Company_Group = models.ManyToManyField(Company)
Brand_Group = models.CharField(u'Brand Group',max_length=255, default="")
Pref_Brand_Name_Flg = models.CharField(u'Preferred Name Flag',max_length=255, default="")
Pref_Brand_Name = models.CharField(u'Preferred Name',max_length=255, default="")
PrimaryContact = models.ForeignKey(UserRole, null=True, blank=True)
class Company(models.Model):
Pref_Company_Name_Flg = models.CharField(u'Preferred Name Flag',max_length=255, default="")
Pref_Company_Name = models.CharField(u'Preferred Name',max_length=255, default="")
Company_Type = models.CharField(u'Company Type',max_length=255, default="")
serializers
class BrandSerializer(serializers.ModelSerializer):
class Meta:
model = Brand
fields = '__all__'
the Serializer as follows ,data_export_setting.Company_form_stand is the field as
class CompanySerializer(serializers.HyperlinkedModelSerializer):
Brand = BrandSerializer(source='brand', read_only=True)
class Meta:
model = Company
Company_form_stand=['id', 'Brand', 'Company_Type','Company_Name','company_Name_SC']
fields = data_export_setting.Company_form_stand
depth = 2
def create(self, validated_data):
return Company.objects.create(**validated_data)
def update(self, instance, validated_data):
instance.__dict__.update(**validated_data)
instance.save()
return instance
the viewset are as follows
class BrandViewSet(viewsets.ModelViewSet):
queryset = Brand.objects.all()
serializer_class = BrandSerializer
model = Brand
def get_serializer(self, *args, **kwargs):
if 'data' in kwargs:
data = kwargs['data']
if isinstance(data, list):
kwargs['many'] = True
return super(BrandViewSet, self).get_serializer(*args, **kwargs)
class CompanyViewSet(viewsets.ModelViewSet):
queryset = Company.objects.all()
serializer_class = CompanySerializer
and I want to show the company objects with Brand objects ,however,it seems to ignore the brand object and its field
appreciate any help ,thanks
Try,
Brand = BrandSerializer(source='brand_set', read_only=True, many=True)
Since, you have defined the field relation as ManyToMany, more than one Brand objects are related to a single Company instance. By using the reverse relation, you can access them in your serializer, and many=True lets the serializer handle multiple objects in the relation.
Models:
class Owner(models.Model):
name = models.CharField(max_length=255)
def __unicode__(self):
return self.name
class SomeThing(models.Model):
own_id = models.IntegerField(unique=True)
description = models.CharField(max_length=255, blank=True)
owner = models.ForeignKey(Owner, blank=True, null=True)
def __unicode__(self):
return self.description
Serializers:
class OwnerNameField(serializers.RelatedField):
def to_internal_value(self, data):
pass
def to_representation(self, value):
return value.name
def get_queryset(self):
queryset = self.queryset
if isinstance(queryset, (QuerySet, Manager)):
queryset = queryset.all()
lista = [Owner(name="------------")]
lista.extend(queryset)
return lista
class OwnerSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Owner
fields = ('name', 'id')
class ThingSerializer(serializers.ModelSerializer):
owner = OwnerNameField(queryset=Owner.objects.all())
class Meta:
model = SomeThing
fields = ('own_id', 'description', 'owner')
Basically it works as intended. But when i add some fields to Owner class i would like to see all these fields in output of ThingSerializer (and be able to parse them - string doesn't suit here). I could change field owner to owner = OwnerSerializer() which gives me what i need. But when i want to add SomeThing object (tested in API browser) i also need add new Owner object - and i don't want it, i want use existing Owner object. How can i achieve it?
Finally i got it. This question describes exactly my problem and provided answers work as a charm!