将一个模型A复制到模型B中出现错误

Question

我试图将模型A复制到模型B，但是由于某种原因，我遇到了唯一约束失败：appname_duplicate.id

Class orignal(models.Model):
  managed = True
  [some_fields]
  def __unicode__(self):
     return self.recipient_email

Class duplicate(models.Model):
  managed = True
  [same_as_Orignal_fields]
  def __unicode__(self):
     return self.recipient_email

功能：

def clone_orignal(source, destination):
    duplicate = list()
    for row in source.objects.all().values():
      if row not in duplicate:
        duplicate.append(destination(**row))
    if duplicate:
      destination.objects.bulk_create(duplicate)

有人可以看看吗？