IntegrityError with save() methode when updating model with UUID Primary Key

Question

IntegrityError when updating 2 models (related OneToOne) with Django CBV with 2 forms

I trying to update the linked OneToOne model in a CBV but got the error bellow.

I can not figure out why it doesn't update instead of create as I pass form2 with Patient instance

django.db.utils.IntegrityError: ERREUR: the value of a duplicate key breaks the unique constraint « Patient_inclusion_id_key » DETAIL: key « (inclusion_id)=(f4a60661-2b26-4ccb-b812-e9b26063df82) » already exist

class InclusionUpdate(SuccessMessageMixin, UpdateView): 
    model = Inclusion
    form_class = InclusionForm
    second_form_class = PatientForm
    template_name = "web/inclusion_form.html"
    success_message = "Inclusion mise à jour avec succès."
    success_url = reverse_lazy('web:inclusion_list')

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.object = None

    def get_context_data(self, **kwargs):
        ....

    def form_valid(self, form, form2):
        inclusion = form.save(commit=False)
        inclusion.save()
        patient = form2.save(commit=False)          # I could comment his line or not dosesn't change
        patient.save()                              #<= this line is raise integrityError
        return super().form_valid(form)

    def form_invalid(self, form, form2):
        context = self.get_context_data(form=form, form2=form2)
        return self.render_to_response(context)

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        form = self.get_form()
        form2 = self.second_form_class(request.POST, instance=Patient.objects.get(inclusion=self.object)) if Patient.objects.filter(inclusion=self.object).exists() else self.second_form_class(request.POST)
        if all((form.is_valid(), form2.is_valid())):
            return self.form_valid(form, form2)        #<= this line is executed
        else:
            return self.form_invalid(form, form2) 

---

EDIT 2023-10-04

According to Django 4.1 documentation (link), this issue should be fixed using update_or_create but I still have the same IntegrityError

my form_valid méthod updated:

    def form_valid(self, form, form2):
        inclusion = form.save(commit=False)
        inclusion.save()
        # Récupérez les données du formulaire form2
        patient_data = form2.cleaned_data

        # Save Patient model updates
        patient, created = Patient.objects.update_or_create(
            uuid=patient_data['uuid'],  # uuid as PK
            defaults={**patient_data, 'inclusion': inclusion}  inclusion as FK
        )
        return super().form_valid(form)