Счетчик дедупликации Django ORM
class Country(models.Model):
name = models.CharField(max_length=255)
class City(models.Model):
country = models.ForeignKey(Country, on_delete=models.CASCADE)
name = models.CharField(max_length=255)
class Score(models.Model):
city = models.ForeignKey(City, on_delete=models.CASCADE)
Мне нужен дедуплицированный подсчет city.country в модели оценки.
canada = Country.objects.create(name="Canada")
USA = Country.objects.crerate(name="USA")
ottawa = City.objects.create(name="Ottawa", country=cannada)
washington = City.objects.create(name="Washington", country=usd)
new_york = City.objects.create(name="New York", country=usd)
Score.objects.create(city=ottawa)
Score.objects.create(city=ottawa)
Score.objects.create(city=washington)
Score.objects.create(city=new_york)
Я хочу, чтобы Канада 1 очко США 2 очка вот так.
city = City.objects.annotate(point= ???)
ottawa city[0].point ==> 1
washington city[1].point ==> 2
new_york city[2].point ==> 2