[英]Django GenericForeignKey: accessor clash when 2 models have same related_name
当我syncdb
,我收到很多这样的错误:
transcription.transcription1: Accessor for field 'participant_content_type' clashes with related field 'ContentType.auxi
liary_model_as_participant'. Add a related_name argument to the definition for 'participant_content_type'.
transcription.transcription1: Reverse query name for field 'participant_content_type' clashes with related field 'Conten
tType.auxiliary_model_as_participant'. Add a related_name argument to the definition for 'participant_content_type'.
我的模型已经有相关名称:
# my base class which I intend to inherit from in many places.
# Many types of AuxiliaryModel will point at participant/match objects.:
class AuxiliaryModel(models.Model):
participant_content_type = models.ForeignKey(ContentType,
editable=False,
related_name = 'auxiliary_model_as_participant')
participant_object_id = models.PositiveIntegerField(editable=False)
participant = generic.GenericForeignKey('participant_content_type',
'participant_object_id',
)
match_content_type = models.ForeignKey(ContentType,
editable=False,
related_name = 'auxiliary_model_as_match')
match_object_id = models.PositiveIntegerField(editable=False)
match = generic.GenericForeignKey('match_content_type',
'match_object_id',
)
class Meta:
abstract = True
class Transcription(AuxiliaryModel):
transcription = models.TextField(max_length=TRANSCRIPTION_MAX_LENGTH,
null=True)
class Meta:
abstract = True
class Transcription1(Transcription):
pass
class Transcription2(Transcription):
pass
class Transcription3(Transcription):
pass
当我注释掉Transcription2
和Transcription3
,问题就消失了,所以related_names似乎冲突了。 我必须使它们独特吗? 如果是这样,有没有一种方法而不必在每个子类中编写样板代码?
从Django docs https://docs.djangoproject.com/en/dev/topics/db/models/#be-careful-with-related-name :
如果在ForeignKey或ManyToManyField上使用related_name属性,则必须始终为该字段指定唯一的反向名称。 这通常会在抽象基类中引起问题,因为此类的字段包含在每个子类中,并且每次属性(包括related_name)的值都完全相同。
要变通解决此问题,当您在抽象基类(仅)中使用related_name时,部分名称应包含'%(app_label)s'和'%(class)s'。
在这种情况下,我认为这会起作用:
participant_content_type = models.ForeignKey(ContentType,
editable=False,
related_name = '%(app_label)s_%(class)s_as_participant')
match_content_type = models.ForeignKey(ContentType,
editable=False,
related_name = '%(app_label)s_%(class)s_model_as_match')
因此,使用%(app_label)_transcription2_as_participant
您可以访问Transcription2.participant_content_type的%(app_label)_transcription2_as_participant
。
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