How to update an object from edit form in Django?

Solution 1:

Why don't you just use ModelForm?

# forms.py
# ...
class MyForm(forms.ModelForm):
    class Meta:
        model = MyModel

# views.py
# ...    
def my_view(request, id): 
    instance = get_object_or_404(MyModel, 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}) 

See https://docs.djangoproject.com/en/3.0/topics/forms/modelforms/#the-save-method for more details.

Solution 2:

Update for Django 1.6 and further version

# forms.py
# ...
class MyForm(forms.ModelForm):

     class Meta:
     model = MyModel

# views.py  

def my_view(request, id): 
    instance = MyModel.objects.get(id=id)
    form = MyForm(request.POST or None, instance=instance)
    if form.is_valid():
          form.save()
          return redirect('next_view')
return direct_to_template(request, 'my_template.html', {'form': form})