Add choices in ListView Django - django

Question

I have the view which displays all transactions. I have a table with contractors and I want to display all rows from this table in the options to <select>. How can i do this?
My view:
class TransactionView(CustomPermissionRequired, ListView):
# Переопределение из MultipleObjectMixin
model = Transaction
context_object_name = 'transactions'
paginate_by = 20
login_url = '/'
permission_required = (
'registration2.can_see_payments',
)
# Переопределение из TemplateResponseMixin
template_name = 'payments.html'
search_fields = [
('contractor_name', 'deal__service__contractor__name__icontains'),
('from_pay_date', 'payment_date__gte'),
('to_pay_date', 'payment_date__lte'),
('tr_id', 'id__icontains')
]
# Переопределение из MultipleObjectMixin
def get_queryset(self):
print('get_def')
filter_args = []
filter_kwargs = {}
for sf in self.search_fields:
if sf[0] is not None:
sf_value = self.request.GET.get(sf[0])
if sf_value:
filter_kwargs[sf[1]] = sf_value
return Transaction.objects.all().select_related('currency',
'payment_source__payment_type',
'deal__service__contractor'
).filter(*filter_args, **filter_kwargs).order_by('-id')
def get_context_data(self, **kwargs):
context = super(TransactionView, self).get_context_data(**kwargs)
for sf in self.search_fields:
if sf[0] is not None:
context[sf[0]] = self.request.GET.get(sf[0])
return context
My models Transaction and Contractors:
class Transaction(models.Model):
id = models.BigIntegerField(blank=True, null=False, primary_key=True)
currency = models.ForeignKey(Currency, null=True, on_delete=models.CASCADE)
deal = models.ForeignKey(Deal, null=True, on_delete=models.CASCADE)
# service_instance = models.ForeignKey(ServiceInstance, null=True, on_delete=models.CASCADE)
payment_source = models.ForeignKey(PayerPaymentSource, null=True, on_delete=models.CASCADE)
payment_date = models.DateTimeField(blank=True, null=True)
amount = models.IntegerField(blank=True, null=True)
status = models.CharField(max_length=255, blank=True, null=True)
context = models.TextField(blank=True, null=True)
class Contractors(models.Model):
id = models.IntegerField(blank=True, null=False, primary_key=True)
name = models.CharField(max_length=255, blank=True, null=True)

Answer 1

You don't show your HTML, but you start from a queryset to get the contractor names and ids.
contractors = Contractors.objects.all().order_by('name').values_list('id, 'name')
If you look at list(contractors) you will see it is a list of 2-tuples as required for choices.
You can use it as such if you dynamically build a form, or you can pass it to your template and iterate through it there to build an options list
{% for c in contractors %} <option ... {{c.0}} ... {{c.1}} ... {% endfor %}
There's also forms.ModelChoiceField which IIRC accepts a queryset (without values_list()) as an argument, and returns the selected [Contractor] instance as its entry in form.cleaned_data.