同一类Django的两个外键

如何访问同一类的两个外键

class Countries(models.Model):
    name = models.CharField(max_length=200,null=True)


class bookings(models.Model):
    Pickup = models.ForeignKey(Countries,on_delete=models.CASCADE,null=True)
    Dropoff = models.ForeignKey(Countries,on_delete=models.CASCADE,null=True)

ERROR reverse accessor  of Pickup clashes with reverse accessser  for Dropoff

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您必须使用related name关键字，这样默认情况下，反向访问将使用相同的名称，这就是可能发生冲突的原因

 class bookings(models.Model):
   Pickup = models.ForeignKey(Countries,on_delete=models.CASCADE,null=True, related_name="pickup")
   Dropoff = models.ForeignKey(Countries,on_delete=models.CASCADE,null=True, related_name="dropoff")

---

您必须使用related name关键字，这样默认情况下，反向访问将使用相同的名称，这就是可能发生冲突的原因

 class bookings(models.Model):
   Pickup = models.ForeignKey(Countries,on_delete=models.CASCADE,null=True, related_name="pickup")
   Dropoff = models.ForeignKey(Countries,on_delete=models.CASCADE,null=True, related_name="dropoff")

---

按以下方式更改您的型号：

class bookings(models.Model):
    Pickup = models.ForeignKey(Countries, on_delete=models.CASCADE, null=True, related_name='pickup_countries')
    Dropoff = models.ForeignKey(Countries, on_delete=models.CASCADE, null=True, related_name='dropoff_countries')

---

参考资料：

按以下方式更改您的型号：

class bookings(models.Model):
    Pickup = models.ForeignKey(Countries, on_delete=models.CASCADE, null=True, related_name='pickup_countries')
    Dropoff = models.ForeignKey(Countries, on_delete=models.CASCADE, null=True, related_name='dropoff_countries')

---

参考：

您应该为

预订

模型中的字段定义

相关的\u名称

。像

Pickup=models.ForeignKey（国家/地区，on_delete=models.CASCADE，null=True，related_name='Pickup'）

您应该为

booking

model中的字段定义

related_name

。比如

Pickup=models.ForeignKey（国家/地区，on\u delete=models.CASCADE，null=True，相关的\u name='Pickup'）