Two fields related in Django - django

Question

I need to update my table every time a new value of "sku" is entered (not to create a new entry), but it does have to happen only if the "client" selected is the same. If the "client" is different, then the model should add a new object with the same "sku", but with different "clients".
I have tried to do the following in my models.py:
class ProductList(models.Model):
id_new = models.IntegerField(primary_key=True)
sku = models.CharField(primary_key=False, max_length=200)
client = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)
name = models.CharField(max_length=256)
description = models.CharField(max_length=1000)
storage = models.CharField(max_length=256)
cost_price = models.CharField(max_length=256)
sell_price = models.CharField(max_length=256)
ncm = models.CharField(max_length=256)
inventory = models.IntegerField(null=True)
class Meta:
unique_together = (('sku', 'client'),)
But it is not working. How can I make that work?

Answer 1

You can try like this:
# form
class MyForm(forms.ModelForm):
class Meta:
model = ProductList
def save(self, *args, **kwargs:
client = self.cleaned_data.get('client') # get client from form cleaned_data
if hasattr(self.instance, 'pk') and self.instance.client != client: # check if client match's already existing instance's client
self.instance.pk = None # make a duplicate instance
self.instance.client = client # change the client
return super(MyForm, self).save(*args, **kwargs)
# views.py
# ...
def my_view(request, id):
instance = get_object_or_404(ProductList, id=id)
form = MyForm(request.POST or None, instance=instance)
if form.is_valid():
form.save()
return redirect('next_view')
return render(request, 'my_template.html', {'form': form})
Update
Um you can override the model as well. you can try like this:
# Untested Code but should work
def save(self, *args, **kwargs):
if self.pk:
current_instance = self.__class__.objects.get(pk=self.pk)
if current_instance.client != self.client:
self.pk = None
return super(ProductList, self).save(*args, **kwargs)