I have an unmanaged model named 'Dummy'. I want to render a form named 'DummyForm' to either create or update records in the table. But I keep getting an error "cursor "_django_curs_10804_sync_1" does not exist". How can I solve this error? Any guidance would be greatly appreciated.

I am not sure if there is something wrong in my view as I am trying to create and update using the same view.

models.py:

class Dummy(models.Model):
    firstname = models.CharField(max_length=255)
    lastname = models.CharField(max_length=255)
    age = models.IntegerField()

    class Meta:
        managed = False
        db_table = 'dummy'

forms.py

class DummyForm(forms.ModelForm):
    class Meta:
        model = Dummy
        fields = '__all__'

views.py

def dummy_update(request, pk):
    instance = Dummy.objects.using('postgresdb').get(pk=pk)

    if request.method == 'POST':
        if instance:
            form = DummyForm(request.POST, instance=instance)
        else:
            form = DummyForm(request.POST)

        if form.is_valid()
            form.save(using='postgresdb')
            return redirect('homepage')
    else:
        if instance:
            form = DummyForm(instance=instance)
        else:
            form = DummyForm()

    return render(request, 'dummy_update.html', {'form': form}

dummy_update.html template

{% block content %}
    <div class="container">
        <form method="POST" enctype="multipart/form-data">
            {% csrf_token %}

            {{ form | crispy }}

            <button class="btn btn-outline-success" type="submit">Update</button>
        </form>
    </div>
{% endblock content %}