我有以下对象结构:
class Customer(models.Model):
name = models.CharField('Customer Name', max_length=64)
class Location(models.Model):
customer = models.ForeignKey(Customer)
groups = models.ManyToManyField(Group, blank=True, null=True)
class Group(models.Model):
name = models.CharField('Group Name', max_length=64)
如何找到客户的所有唯一组对象?