Question

class Professional(models.Model):
    ...
    favoriting_customers = models.ManyToManyField(
        'customers.Customer', blank=True,
        through='favorites.FavoriteProfessional')

    recommending_customers = models.ManyToManyField(
        'customers.Customer', blank=True,
        through='recommendations.ProfessionalRecommendation')

当我删除ManyToMany字段时，我没有错误。但是，当我运行＆＃39; python manage.py makemigrations＆＃39;时，我得到了SystemCheckError。

错误： professional.Professional.favoriting_customers :( fields.E304）＆＃39; Professional.favoriting_customers＆＃39;的反向访问者与“Professional.recommending_customers＆＃39;”的反向访问者发生冲突。提示：在＆＃39; Professional.favoriting_customers＆＃39;的定义中添加或更改related_name参数。或者＆＃39; Professional.recommending_customers＆＃39;。 professional.Professional.recommending_customers :( fields.E304）＆＃39; Professional.recommending_customers＆＃39;的反向访问者与“Professional.favoriting_customers＆＃39;”的反向访问者发生冲突。提示：在＆＃39; Professional.recommending_customers＆＃39;的定义中添加或更改related_name参数。或者＆＃39; Professional.favoriting_customers＆＃39;。

Answer 1

根据 HINT 的建议，您需要使用related_name来避免backward relations上的冲突。每次在同一模型中有两个与同一对象相关的字段（在您的情况下为customers.Customer）时，您将需要这样做。

您可以尝试这样的事情：

class Professional(models.Model):
    ...
    favoriting_customers = models.ManyToManyField(
        'customers.Customer', blank=True,
        through='favorites.FavoriteProfessional',
        related_name='favorites'
    )

    recommending_customers = models.ManyToManyField(
        'customers.Customer', blank=True,
        through='recommendations.ProfessionalRecommendation',
        related_name='recommendations'
    )

如果您对Professional表的向后关系不感兴趣，可以使用'+'作为related_name禁用它：

class Professional(models.Model):
    ...
    favoriting_customers = models.ManyToManyField(
        'customers.Customer', blank=True,
        through='favorites.FavoriteProfessional',
        related_name='+'
    )

    recommending_customers = models.ManyToManyField(
        'customers.Customer', blank=True,
        through='recommendations.ProfessionalRecommendation',
        related_name='+'
    )

此外，您应该be careful with related_name

Django ManyToManyField SystemCheckError

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