Django模型中条件m2m属性个数的求法

Question

例如，Django模型中有两个类：

class Generus(models.Model):
    user    = models.OneToOneField(User, on_delete=models.CASCADE)

    LIST_KLP = (
        ('Marbar', 'Marbar'),
        ('Marsel', 'Marsel'),
    )
    klp = models.CharField(max_length=6, choices=LIST_KLP, default='Marbar')

    def __str__(self):
        return self.user.first_name

class Event(models.Model):
    LIST_EVENT = (
        ('Mince', 'Mince'),
        ('Persami', 'Persami'),
    )
    name_event = models.CharField(max_length=20, choices=LIST_EVENT, default='Persami')
    attendance = models.ManyToManyField(Generus, related_name='foo', blank=True)

    def __str__(self):
        return '%s %s' % (self.jenis_kegiatan, self.tanggal)

从这些课程中，我想得到klp=Marsel的出席人数。有什么可能的解决办法吗？你知道吗

Answer 1

我相信你应该能做到。。。你知道吗

Event.objects.filter(foo__klp='Marsel')