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Incorrect type. Expected pk value, received str in DRF.(one to one field)

When I send post request with data in profile model at that time this error show.
Error
{
"user_name": [
"Incorrect type. Expected pk value, received str."
] }
I saw this answer but don't know how to implement SlugRelatedField in serializers(OneToOneField)
models.py:
class CustomUser(AbstractUser):
# username_validator = UnicodeUsernameValidator()
username = models.CharField(
max_length=80,
unique=True,
)
email = models.EmailField(
unique=True,
blank=True,
)
.....
def __str__(self):
return '%s' %(self.username)
class Profile(models.Model):
user_name = models.OneToOneField(to = CustomUser,on_delete=models.CASCADE)
full_name = models.CharField(null=True,max_length=15, blank=True)
public_name = models.CharField(null=True,max_length=15, blank=True)
....
serializers.py:
class ProfileSerializer(serializers.ModelSerializer):
class Meta:
model = Profile
fields = ['user_name','full_name','public_name']
views.py:
class ProfileApiview(CreateAPIView):
queryset = Profile.objects.all()
serializer_class = ProfileSerializer

#Pradip - Have a look at this.
class ProfileSerializer(serializers.ModelSerializer):
user_name = serializers.PrimaryKeyRelatedField(read_only=True)
class Meta:
model = Profile
fields = ['user_name','full_name','public_name']
def create(self, validated_data):
user = self.context['request'].user
profile = Profile.objects.create(
user_name=user, full_name=validated_data['full_name'].............)
return profile

Can't get Django REST to save POST object request in model

Trying to allow users to create an object and save it in my model. My front-end POST requests are getting a 201 confirmation response, so no traceback error from the backend. The data seems to be getting serialized but not saved in my model.
Here is my code...
model.py:
class Bucket(models.Model):
category_options = (
('personal', 'Personal'),
('social', 'Social'),
)
class BucketObjects(models.Manager):
def get_queryset(self):
return super().get_queryset()
owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='buckets')
admin_user = models.ManyToManyField(settings.AUTH_USER_MODEL, related_name='admin_user')
guest_user = models.ManyToManyField(settings.AUTH_USER_MODEL, related_name='guest_user', blank=True)
category = models.CharField(max_length=30, choices=category_options)
name = models.CharField(max_length=35)
created = models.DateTimeField(default=timezone.now, blank=True)
slug = AutoSlugField(populate_from = "random_string", blank=True)
stock_count = models.IntegerField(blank=True, null=True)
stock_list = ArrayField(models.CharField(max_length=6,null=True),size=30,null=True, blank=True)
about = models.CharField(max_length=200)
objects = models.Manager()
bucketobjects = BucketObjects()
class Meta:
ordering = ('-created',)
def save(self, *args, **kwargs):
if self.stock_list:
self.stock_count = len(self.stock_list)
super().save(*args, **kwargs)
serializer.py:
class BucketCreateSerializer(serializers.ModelSerializer):
class Meta:
model = Bucket
fields = ('owner','category','name','about')
read_only_fields = ['owner']
def create(self, validated_data):
user = self.context['request'].user
bucket = Bucket.objects.create(
owner=user,
**validated_data
)
bucket.save()
return bucket
view.py:
class CreateBucket(generics.CreateAPIView):
permission_classes = [IsAuthenticated]
serializer_class = BucketCreateSerializer
queryset = Bucket.objects.all()
How can I go about solving this?

Django User model saves twice into database

I am trying to create multi user registration system with Django. However, anytime I call the save() method to save a User type, it saves into the User table twice. The funny thing about the second model that is saved is that many required fields are empty.
I am using a custom user model that I created from AbstractBaseUser. I also rewrote the forms for the CustomUser model. For the multiple user types, I am using a profile model (Student model has a OneToOne field to the user model)
models.py:
class User(AbstractBaseUser, PermissionsMixin):
# I've removed some unimportant code here
email = models.EmailField(
verbose_name='email address',
max_length=255,
unique=True,
)
class Types(models.TextChoices):
STUDENT = 'STUDENT', 'Student'
DEPARTMENT_USER = 'DEPARTMENT_USER', 'Department user'
ADMIN = 'ADMIN', 'Admin'
user_type = models.CharField(_('Type'), max_length=50, choices=Types.choices, default=Types.STUDENT)
first_name = models.CharField(_('First name'), max_length=70, blank=False, default="")
middle_name = models.CharField(_('Middle name'), max_length=70, blank=True, default="")
last_name = models.CharField(_('Last name'), max_length=70, blank=False, default="")
is_active = models.BooleanField(default=True)
is_staff = models.BooleanField(default=False) # a admin user; non super-user
is_superuser = models.BooleanField(default=False) # a superuser
last_login = models.DateTimeField(null=True, blank=True)
date_joined = models.DateTimeField(auto_now_add=True)
USERNAME_FIELD = 'email'
EMAIL_FIELD = 'email'
REQUIRED_FIELDS = ['user_type', 'first_name', 'last_name'] # Email & Password are required by default.
objects = UserManager()
class Meta:
verbose_name = ('user')
verbose_name_plural = ('users')
#db_table = 'auth_user'
abstract = False
class AccountConfirmed(models.Model):
# Model to determine which users have confirmed their email addresses.
user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='accountconfirmed')
email_confirmed = models.BooleanField(default=False)
reset_password = models.BooleanField(default=False)
class Meta:
app_label = 'auth'
# When the user model is created, through signals an AccountConfirmed model is also created.
# The email_confirmed and reset_password field is set to false.
#receiver(models.signals.post_save, sender=User)
def update_user_profile(sender, instance, created, **kwargs):
if created:
AccountConfirmed.objects.create(user=instance)
instance.accountconfirmed.save()
######################################################
######################################################
class Student(User):
# This is the model class for students
user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True, related_name='students')
matric_number = models.CharField(_('Matriculation number'), max_length=11, blank=False)
department = models.CharField(_('Department'), max_length=40, blank=False)
# has_graduated, level, etc. future possibilities
def __str__(self):
return f'{self.user.email}'
forms.py:
class StudentSignupForm(UserCreationForm):
# first_name = forms.CharField(max_length=70)
# middle_name = forms.CharField(max_length=70, required=False)
# last_name = forms.CharField(max_length=70)
matric_number = forms.CharField(min_length=10, max_length=11, help_text='Your Matric number must be 10 characters')
department = forms.CharField(max_length=40, help_text='e.g Computer Science')
class Meta(UserCreationForm.Meta):
model = User
fields = UserCreationForm.Meta.fields + ('matric_number', 'department')
#transaction.atomic
def save(self, commit=True):
# Save the User instance and get a reference to it
user = super().save(commit=False)
user.user_type = User.Types.STUDENT
user.is_active = False
#if commit:
user.save()
print(f' forms.py {user.email} {user.first_name}')
student = Student.objects.create(user=user, matric_number=self.cleaned_data.get('matric_number'), department=self.cleaned_data.get('department'))
# Add other details
# Return User instance, not Student instance
return user
views.py:
class StudentUserSignupView(CreateView):
model = User
template_name = 'account/signup.html'
form_class = StudentSignupForm
def get_context_data(self, **kwargs):
kwargs['user_type'] = 'STUDENT'
return super().get_context_data(**kwargs)
def form_valid(self, form):
user = form.save()
#login(self.request, user)
send_verification_mail(self, user)
return redirect('verification_sent')
Anytime a user signs up, this is what the students table looks like:
Also, this is what the users table look like after signup (with the multiple saves)
So how do I correct the multiple saves in the user table?
Also, How is it even possible to save a model with most of the required fields empty?

As pointed out by #RaghavKundra, the line below was what caused the problem of saving multiple times to the database
class Student(User):
Instead of that, it should be
class Student(models.Model):

Unable to register user - TypeError: Direct assignment to the reverse side of a related set is prohibited. Use searches.set() instead

I've set up my models, serializers and viewsets in my Django REST API to assign a search record to a particular user, and to associate all the relevant user's searches to their record in the User model. It was all working fine, but I'm now getting the TypeError error message (in the subject line of this question) when I try to create a new user. I've listed the relevant models, serializers and viewsets below. Please could anyone take a look and let me know where I'm going wrong? Any help would be very much appreciated.
User serializer:
class UserSerializer(serializers.ModelSerializer):
searches = serializers.PrimaryKeyRelatedField(many=True, queryset=SearchHistoryModel.objects.all())
class Meta:
model = User
fields = ('id', 'username', 'email', 'password', 'searches')
extra_kwargs = {'email': {
'required': True,
'validators': [UniqueValidator(queryset=User.objects.all())]
}}
def create(self, validated_data):
user = User.objects.create_user(**validated_data)
Token.objects.create(user=user)
return user
User viewset:
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
permission_classes = [permissions.AllowAny]
Search model:
class SearchHistoryModel(models.Model):
"""
Stores each user's search submission
"""
created_date = models.DateTimeField(auto_now_add=True)
owner = models.ForeignKey(User, related_name='searches', on_delete=models.CASCADE)
cpu_component_name = models.CharField(max_length=10, blank=False)
cpu_subcomponent_name = models.CharField(max_length=50, blank=False)
motherboard_name = models.CharField(max_length=20, blank=False)
gpu_component_name = models.CharField(max_length=10, blank=True, null=True)
gpu_subcomponent_name = models.CharField(max_length=50, blank=True, null=True)
gpu_subcomponent_quantity = models.PositiveIntegerField(default=0)
ram_component_name = models.CharField(max_length=15, blank=True, null=True)
ram_component_quantity = models.PositiveIntegerField(default=0)
ssd_component_name = models.CharField(max_length=15, blank=True, null=True)
ssd_component_quantity = models.PositiveIntegerField(default=0)
hdd_component_name = models.CharField(max_length=20, blank=True, null=True)
hdd_component_quantity = models.PositiveIntegerField(default=0)
optical_drive_name = models.CharField(max_length=15, blank=True, null=True)
class Meta:
verbose_name = 'Search'
verbose_name_plural = 'Searches'
ordering = ['owner', 'created_date']
def __str__(self):
return '{}\'s search choices'.format(self.owner)
Search serializer:
class SearchHistorySerializer(serializers.ModelSerializer):
"""
Serializes the user's search history data passed into the SearchHistoryModel
Associates each search with the relevant user
"""
owner = serializers.ReadOnlyField(source='owner.username')
class Meta:
model = SearchHistoryModel
fields = (
'id', 'created_date', 'owner', 'cpu_component_name', 'cpu_subcomponent_name',
'motherboard_name', 'gpu_component_name', 'gpu_subcomponent_name',
'gpu_subcomponent_quantity', 'ram_component_name', 'ram_component_quantity',
'ssd_component_name', 'ssd_component_quantity', 'hdd_component_name',
'hdd_component_quantity', 'optical_drive_name'
)
Search viewset:
class SearchHistoryViewSet(viewsets.ModelViewSet):
queryset = SearchHistoryModel.objects.all()
serializer_class = SearchHistorySerializer
permission_classes = [permissions.IsAuthenticated]
def perform_create(self, serializer):
serializer.save(owner=self.request.user)

In user = User.objects.create_user(**validated_data), validated_data contains a searches value which is an id.
But actually the ForeignKey is in the other sense : in Searches model, and to refer to a User instance, not the opposite.
To link a user to searches, it is not in User DB table that you write an id, but in Searches that you write a User id.
class UserSerializer(serializers.ModelSerializer):
(...)
def create(self, validated_data):
# Extract the value from 'validated_data'
search_ids = validated_data.pop('searches', None)
user = User.objects.create_user(**validated_data)
Token.objects.create(user=user)
# Update existing search instances
for search_id in search_ids:
Search.objects.filter(id=search_id).update(owner=user)
return user

Django-DRF See all posts from friends

I just started toying around with the Django Rest Framework, so I'm still not entirely sure what exactly is going on. But I have a user model, a friend model, and a post model, I also have my serializers and views in order. But, I can't figure out how to return all the posts from my user's friends. Any help would be greatly appreciated.
models.py
class CustomUser(AbstractBaseUser, PermissionsMixin):
email = models.EmailField('email address', unique=True, db_index=True)
password1 = models.CharField(max_length=50)
username = models.CharField('username', max_length=50, unique=True, db_index=True)
image = models.FileField(upload_to='photos', null=True, blank=True)
joined = models.DateTimeField(auto_now_add=True)
is_active = models.BooleanField(default=True)
is_admin = models.BooleanField(default=False)
date_joined = models.DateTimeField(_('date joined'), default=timezone.now)
USERNAME_FIELD = 'username'
REQUIRED_FIELDS = []
objects = CustomUserManager()
def __unicode__(self):
return self.username
class Meta:
unique_together = (('username', 'password1'),)
class Friendship(models.Model):
created_at = models.DateTimeField(auto_now_add=True, editable=False)
creator = models.ForeignKey(CustomUser, related_name="friendship_creator")
friend = models.ForeignKey(CustomUser, related_name="friends")
class Post(models.Model):
poster = models.ForeignKey(CustomUser)
body = models.CharField(max=200)
def save(self, *args, **kwargs):
super(Post, self).save(*args, **kwargs)
serializers.py
class FriendSerializer(HyperlinkedModelSerializer):
class Meta:
model = Friendship
fields = ('creator', 'friend', 'created_at')
readonly_fields = 'created_at'
class CustomUserSerializer(HyperlinkedModelSerializer):
friends = FriendSerializer(many=True)
class Meta:
model = CustomUser
fields = ('email', 'username', 'password1', 'image', 'friends')
readonly_fields = 'image'
views.py
class FriendViewSet(ModelViewSet):
queryset = CustomUser.objects.all()
serializer_class = FriendSerializer
class UserProfileViewSet(RetrieveModelMixin, UpdateModelMixin, GenericViewSet):
queryset = CustomUser.objects.all()
serializer_class = CustomUserSerializer

This may get you started,
So what you need to do first is get all the friends, you can do that by using
friends = <user_objects>.Friendship_set.all()
Read more about is here.
Now that you have all the friends of that particular user, covert their IDs to list and use the in list filter.
Post.objects.filter(poster__id__in=[list_of_ids_of_friends])
See this answer for filtering on foreign key properties.