如何计算每个查询集的实例数？姜戈
How can I count the number of instances per a queryset? Django
我正在编写一项操作，将一个字段设置为等于通过外键附加到它的实例数（见下文）
Models.py
class competition(models):
competition_name = models.CharField(max_length = 50)
class people(models):
competition = models.ForeignKey(competition)
fullname = models.CharField(max_length = 100)
Admin.py
def people_in_competition:
for X in queryset:
X.number_of_people = X.count(X.set_all) #(I want the number of people in this competition in this part)
X.save()
当然这给了我一个错误，因为我似乎无法在 admin.py 中使用 _set_all，它只适用于模板吗？计算该数字的最佳方法是什么？
X.number_of_people = X.people_set.all().count()
我正在编写一项操作，将一个字段设置为等于通过外键附加到它的实例数（见下文）
Models.py
class competition(models):
competition_name = models.CharField(max_length = 50)
class people(models):
competition = models.ForeignKey(competition)
fullname = models.CharField(max_length = 100)
Admin.py
def people_in_competition:
for X in queryset:
X.number_of_people = X.count(X.set_all) #(I want the number of people in this competition in this part)
X.save()
当然这给了我一个错误，因为我似乎无法在 admin.py 中使用 _set_all，它只适用于模板吗？计算该数字的最佳方法是什么？
X.number_of_people = X.people_set.all().count()