Django modal autoimplement - django

Question

Can anyone advise on how to deal with retrieving data from other models in Django? I was able to put information with the name of the company in the form, but after choosing from dropdown, I would like the tax identification number from database to be completed automatically. The problem is both the automatic completion and the binding and extraction of data.
p[1]: https://i.stack.imgur.com/V3TJ7.png
p[2]: https://i.stack.imgur.com/qZYAG.png
Model:
klient_lista = Klient.objects.all().values_list("nazwa_firmy", "nazwa_firmy")
class Faktura(models.Model):
numer = models.CharField(max_length=260, blank=False, null=False, unique=True)
klient = models.CharField(max_length=260, choices=klient_lista)
NIP = models.CharField(max_length=260)
kwota_netto = models.FloatField(blank=False, null=True)
VAT = models.FloatField(blank=False, null=True)
kwota_brutto = models.FloatField(blank=False, null=True)
views:
#login_required
def Faktury(request):
faktura = Faktura.objects.all()
faktura_Form = Faktura_Form(request.POST or None)
if faktura_Form.is_valid():
faktura_Form.save()
return redirect(Faktury)
return render(request, 'Faktury.html', {'form': Faktura_Form, 'faktura': faktura})

Answer 1

You don't need to store klient objects in a variable instead use foreign key to connect the two tables. I hope you refer to the "number" field by tax identification number and it is defined in klient model.
class Faktura(models.Model):
klient = models.ForeignKey(Klient,on_delete=models.CASCADE)
NIP = models.CharField(max_length=260)
kwota_netto = models.FloatField(blank=False, null=True)
VAT = models.FloatField(blank=False, null=True)
kwota_brutto = models.FloatField(blank=False, null=True)
To use client name include following in you client model
class Klient(models.Model):
...model fields
def __str__(self):
return self.name
replace name with the field which stores client name