django 过滤器两个 ManyToManyField 相等

Question

class VideoUserModel(models.Model):
    user = models.ManyToManyField(get_user_model())
    viewlist = models.ManyToManyField(get_user_model(), related_name='view_list', blank=True, null=True)

我想获取 user 的查询集列表等于 viewlist .
这该怎么做？ VideoUserModel.objects.all().filter(user=**viewlist**)

Answer 1

对此没有简单的答案。我们可以通过计算 nuser 的数量来做到这一点。 s，viewlist中的项目数关系和 user 中的项目数也在 nuser然后检查这三个是否都相等:

from django.db.models import Count, F, Q

VideoUserModel.objects.annotate(
    nuser=Count('user', distinct=True),
    nview=Count('viewlist', distinct=True),
    nuserfilter=Count('user', filter=Q(user=F('viewlist')), distinct=True)
).filter(
    nuser=F('nview'),
    nview=F('nuserfilter')
)

Note: It is normally better to make use of the settings.AUTH_USER_MODEL [Django-doc] to refer to the user model, than to work with the get_user_model() method [Django-doc], since that requires loading the auth app before the current app. For more information you can see the referencing the User model section of the documentation.