一个模型中有两个外键指向同一张表时，建立迁移模型时报错：“ HINT: Add or change a related_name argument to the definition for 'Ans

class AnswersModel(models.Model):
   author = models.ForeignKey(FrontUserModel,null=True,related_name='answers_user')
   ……
   relay_to = models.ForeignKey(FrontUserModel,null=True,related_name='relay_to_user')

当模型执行迁移时会报：HINT: Add or change a related_name argument to the definition for 'AnswersModel.author' or 'AnswersModel.relay_to错误。
缘由是由于author 和relay_to字段指向同一个模型的外键反向关联名称产生了冲突。FrontUserModel模型对author的反向关联名称为AnswersModel_set() 。FrontUserModel模型对relay_to的反向关联名称为AnswersModel_set()。所以，须要给外键增长related_name属性，自定义关联名称。