类型错误：'int'对象不是可迭代的序列化程序 Django 序列化程序用于一对多

Question

>我面临着一个奇怪的情况，以下是我的模型代码。

class Sector(models.Model):
sector_name = models.CharField(max_length=255, null=False)
sector_desc = models.CharField(max_length=1024, null=False)
def __set__(self):
return "{} - {}".format(self.sector_name, self.sector_desc)

class TrailCompany(models.Model):
sector = models.ForeignKey(Sector, on_delete=models.CASCADE, related_name="sector_id")
comp_name = models.CharField(max_length=255, null=False)
comp_desc = models.CharField(max_length=1024, null=False)
def __set__(self):
return "{} - {}".format(self.sector, self.comp_name, self.comp_desc)

class Trail(models.Model):
company = models.ForeignKey(TrailCompany, on_delete=models.CASCADE, related_name="company_id")
trail_id = models.CharField(max_length=255, null=False)
tri = models.CharField(max_length=255, null=False)
exp_pdufa = models.CharField(max_length=255, null=False)
def __set__(self):
return "{} - {}".format(self.company, self.exp_pdufa, self.trail_id, self.tri, self.exp_pdufa)

以下是我的序列化程序代码，

class SectorSerializer(serializers.ModelSerializer):
class Meta:
model = Sector
fields = '__all__'

class TrailCompanySerializer(serializers.ModelSerializer):
sectors = SectorSerializer(source="sector_id", many=True)
class Meta:
model = TrailCompany
fields = '__all__'

class TrailSerializer(serializers.ModelSerializer):
companies = TrailCompanySerializer(source="company_id", many=True)
class Meta:
model = Trail
fields = '__all__'

当我尝试对对象进行serilization时，我收到所述错误，

trail_query = Trail.objects.all()
trails = TrailSerializer(trail_query, many=True)
return Response({"success": True, 'trails': trails.data})

请帮助我找出并解决问题。谢谢。

Answer 1

看起来您的错误在以下行中：

companies = TrailCompanySerializer(source="company_id", many=True)

从Trail的角度来看，Trail<>TrailCompany是一对一的关系。 例如，Trail只知道与它相关的一个TrailCompany。因此，您不需要many=True属性。

我也认为来源应该是company而不是company_id.company_id是主键，而company是相关对象

Answer 2

选定的答案对我不起作用。但是，以下方法有效：

company = TrailCompanySerializer(many=True)

还要记住像这样related_name字段中放置company：

company = models.ForeignKey(TrailCompany, on_delete=models.CASCADE, related_name="company")