Question

还是一个新手，我必须改编Django（v1.10）脚本。原始脚本使用主类“ initiative”，该主类可以具有任意数量的“支持者”。

我必须进行的适应包括在“主动”（类似的行为，不同的领域）中拥有另一个名为“策略”的主类。我在“ initiative”和“ policy”上停留在ManyToManyField上，它应该指向Supporters，在这里我试图使用GenericRelation支持两个主要类。我收到以下错误消息：

initproc.Supporter: (fields.E336) The model is used as an intermediate model by 'initproc.Initiative.supporters', but it does not have a foreign key to 'Initiative' or 'User'.
initproc.Supporter: (fields.E336) The model is used as an intermediate model by 'initproc.Policy.supporters', but it does not have a foreign key to 'Policy' or 'User'.

我的models.py（删除了所有不相关的内容）之前：

# ------------------------------ Initiative ------------------------------------
class Initiative(models.Model):

  supporters = models.ManyToManyField(User, through="Supporter")


# ------------------------------- Supporter -------------.----------------------
class Supporter(models.Model):

  class Meta:
    unique_together = (("user", "initiative"),)

  user = models.ForeignKey(User)
  initiative = models.ForeignKey(Initiative, related_name="supporting")

修改后：

# ------------------------------- Supporter ------------------------------------
class Supporter(models.Model):

  class Meta:
    unique_together = (("user", "target_type", "target_id"),)

  user = models.ForeignKey(User)

  target_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
  target_id = models.IntegerField()
  target = GenericForeignKey('target_type', 'target_id')

# -------------------------------- Policy --------------------------------------
class Policy(PolicyBase):

  supporters = models.ManyToManyField(User, through="Supporter")

# ------------------------------ Initiative ------------------------------------
class Initiative(models.Model):

  supporters = models.ManyToManyField(User, through="Supporter")

这将引发以上错误。我想我了解的问题不是用户的ForeignKey（未更改），而是我试图使Supporter同时适用于Initiative和Policy。我只能找到through_fields寻找解决方案，但我想我也在寻找错误的地方。

问题：
如何设置一个指向ManyToManyField上多个类的GenericForeignKey？我也想知道现在必须在哪里放置related_name参数。

如何设置一个指向ManyToManyField上多个类的Django GenericForeignKey？

0 个答案: