diff options
Diffstat (limited to 'django/forms')
| -rw-r--r-- | django/forms/models.py | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/django/forms/models.py b/django/forms/models.py index d8db4b006a..67006ba390 100644 --- a/django/forms/models.py +++ b/django/forms/models.py @@ -1134,13 +1134,16 @@ class ModelChoiceIterator: yield ("", self.field.empty_label) queryset = self.queryset # Can't use iterator() when queryset uses prefetch_related() - if not queryset._prefetch_related_lookups and queryset._result_cache is None: + if not queryset._prefetch_related_lookups: queryset = queryset.iterator() for obj in queryset: yield self.choice(obj) def __len__(self): - return len(self.queryset) + (1 if self.field.empty_label is not None else 0) + # count() adds a query but uses less memory since the QuerySet results + # won't be cached. In most cases, the choices will only be iterated on, + # and __len__() won't be called. + return self.queryset.count() + (1 if self.field.empty_label is not None else 0) def choice(self, obj): return (self.field.prepare_value(obj), self.field.label_from_instance(obj)) |