如何在 views.py 中创建 Django model？

Question

In a DetailView page for object "Patient", I have a form. When the form is filled and submitted, I want to create a "Location" object. Then, I want to create a ForeignKey pointing to the "Patient" object that we are looking at in the DetailView.

As you can see, if the form is valid, I call the model constructor, save the information and connect it to the patient object. However when I check Django Admin, I can't see a new object created. I totally improvised as I couldn't find examples online. Is this the way to do it?

class PatientDetailView(DetailView, FormMixin):
    model=Patient
    form_class = PastLocationForm
    #template_name = 'patient_detail.html'

    def get_success_url(self):
        return reverse('patient_detail', kwargs={'pk': self.object.pk})

    def post(self, request, *args, **kwargs):
        if not request.user.is_authenticated:
            return HttpResponseForbidden()
        self.object = self.get_object()

        form = self.get_form()

        if form.is_valid():
            pastLocationDetail = Location()
            setattr(pastLocationDetail,'location',str(form.cleaned_data['location']).split(',')[0])
            setattr(pastLocationDetail,'address',str(form.cleaned_data['location']).split(',')[1].split(', ')[0])
            setattr(pastLocationDetail,'district',str(form.cleaned_data['location']).split('District: ')[1].split(',')[0])
            setattr(pastLocationDetail,'grid_x',str(form.cleaned_data['location']).split('Coordinates: (')[1].split(', ')[0])
            setattr(pastLocationDetail,'grid_y',str(form.cleaned_data['location']).split('Coordinates: (')[1].split(', ')[1][:-1])
            setattr(pastLocationDetail,'date_from',form.cleaned_data['date_from'])
            setattr(pastLocationDetail,'date_to',form.cleaned_data['date_to'])
            setattr(pastLocationDetail,'details',form.cleaned_data['details'])
            setattr(pastLocationDetail,'patient', self.object)

            return self.form_valid(form)
        else:
            return self.form_invalid(form)

Location model

class Location(models.Model):
    patient = models.ForeignKey(Patient, related_name='locations', on_delete=models.CASCADE, null=True, blank=True)
.
.

Note: I printed out both the objects

print(type(self.object))
print(pastLocationDetail)

And everything seems fine. I really don't understand why it is not written to the database

Answer 1

Did you call save method? Django orm need call save to write instance data into database. See this Django model instance docs .

if form.is_valid():
    pastLocationDetail = Location()
    ...
    pastLocationDetail.save()  # this line required for writing model instance to database 
    return self.form_valid(form)
else:
    return self.form_invalid(form)

It is also recommended that you view this document to better use form.