how to fix django Model instance - django

Question

error messages
ValueError: Cannot assign "<User: user0#example.com>": "Diagnoses.owner" must be a "Patient" instance
i get the above error when i try to create either a new card or diagnoses.
The card and diagnoses are meant to be an instance of the patient, just like the way a patient has a card and also diagnoses. The patient class has a foregin key referencing the User.
Here is the code
views.py
from django.shortcuts import render
from rest_framework.generics import ListCreateAPIView, RetrieveUpdateDestroyAPIView
from .serializers import PatientsSerializer, PatientsCardSerializer, PatientsDiagnosesSerializer
from .models import Patient, Card, Diagnoses
from rest_framework import permissions
from .permissions import IsOwner
# Patient Views
class PatientListAPIView(ListCreateAPIView):
serializer_class = PatientsSerializer
queryset = Patient.objects.all()
permission_classes = (permissions.IsAuthenticated, IsOwner,)
def perform_create(self, serializer):
return serializer.save(owner=self.request.user)
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
class PatientDetailAPIView(RetrieveUpdateDestroyAPIView):
serializer_class = PatientsSerializer
permission_classes = (permissions.IsAuthenticated, IsOwner,)
queryset = Patient.objects.all()
lookup_field = "id"
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
class PatientCardListAPIView(ListCreateAPIView):
serializer_class = PatientsCardSerializer
queryset = Card.objects.all()
permission_classes = (permissions.IsAuthenticated,)
def perform_create(self, serializer):
return serializer.save(owner=self.request.user)
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
class PatientCardDetailAPIView(RetrieveUpdateDestroyAPIView):
serializer_class = PatientsCardSerializer
permission_classes = (permissions.IsAuthenticated, IsOwner,)
queryset = Card.objects.all()
lookup_field = "id"
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
class PatientDiagnosesListAPIView(ListCreateAPIView):
serializer_class = PatientsDiagnosesSerializer
queryset = Diagnoses.objects.all()
permission_classes = (permissions.IsAuthenticated,)
def perform_create(self, serializer):
return serializer.save(owner=self.request.user)
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
class PatientDiagnosesDetailAPIView(RetrieveUpdateDestroyAPIView):
serializer_class = PatientsDiagnosesSerializer
permission_classes = (permissions.IsAuthenticated, IsOwner,)
queryset = Diagnoses.objects.all()
lookup_field = "id"
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
Models.py
class Patient(models.Model):
name = models.CharField(max_length=255, null=True)
country = models.CharField(max_length=255, null=True)
state = models.CharField(max_length=255, null=True)
phone = models.CharField(max_length=255, null=True)
email = models.CharField(max_length=255, null=True)
owner = models.ForeignKey(to=User, null=True, on_delete=models.CASCADE)
def __str__(self):
return self.name
class Card(models.Model):
name = models.CharField(max_length=255, null=True)
card_number = models.CharField(max_length=255, null=True)
owner = models.OneToOneField(Patient, null=True, blank=True, on_delete=models.CASCADE)
def __str__(self):
return (self.patient.name)+"'s card"
class Diagnoses(models.Model):
sickness = models.CharField(max_length=255, null=True)
note = models.TextField(max_length=255, null=True)
owner = models.ForeignKey(Patient, null=True, on_delete=models.SET_NULL)
def __str__(self):
return (self.patient.name)+"'s diagnoses"

Answer 1

So far, self.request.user is a User Object. You cannot save it to the API or save to the model because of that. And for clarity, it's not a Patient Object.
Based on your situation, I would queue the Patient object with the User object (if this was a one-way reference object), and put that in the argument and do the save() method.
class PatientCardListAPIView(ListCreateAPIView):
serializer_class = PatientsCardSerializer
queryset = Card.objects.all()
permission_classes = (permissions.IsAuthenticated,)
def perform_create(self, serializer):
getPatientFromUser = Patient.objects.get(owner=self.request.user)
# getPatientFromUser returns `Patient` Instance. So you could bind it in `Card` Model.
return serializer.save(owner=getPatientFromUser)
def get_queryset(self):
return self.queryset.filter(owner=self.request.user)
Notes:
This is a solution for a one-way reference. (User being referred to as Patient)
If you have a cross-reference relationship between User and Patience (where User and Patience has a ForeignKey on each other), then declare your User Model.
The solution queries the Patient from User. As User is incompatible with that Foreign Object.