https://stackoverflow.com/questions/4184558/django-query-filter-on-manytomany-is-empty
class TestModel(models.Model): name = models.CharField(_('set name'), max_length=200) manytomany = models.ManyToManyField('AnotherModel', blank=True, null=True) TestModel.objects.filter(manytomany=None) TestModel.objects.exclude(manytomany=None)