'Subcategory' 对象的 Django nestesd 序列化程序问题不可迭代

Question

我想用我的产品序列化程序获取类别和子类别，但它向我显示子类别对象不可迭代的错误。我不知道有什么问题我尝试了相同的嵌套过程并且它以前适用于另一个字段但不适用于子类别。

#这是我的模型所以你明白关系

class Category(models.Model):
    name = models.CharField(max_length=220)

    def __str__(self):
        return self.name



class Subcategory(models.Model):
    category = models.ForeignKey(Category, on_delete=models.CASCADE)
    name = models.CharField(max_length=220)





class Product(models.Model):

    product_type_choices = [
        ('With Cylinder', 'With Cylinder'),
        ('Without Cylinder', 'Without Cylinder'),
    ]

    setup_type_choices = [
        ('Yes', 'Yes'),
        ('No', 'No'),
    ]

    user = models.ForeignKey(Vendor, on_delete=models.CASCADE)
    name = models.CharField(max_length=220)
    image = models.ImageField(null=True, blank=True)
    product_type = models.CharField(max_length=220, null=True, blank=True, choices=product_type_choices)
    setup_type = models.CharField(max_length=220, null=True, blank=True, choices=setup_type_choices)
    subcategory = models.ForeignKey(Subcategory, on_delete=models.CASCADE, null=True, blank=True)
    description = models.TextField(max_length=10000)
    rating = models.DecimalField(max_digits=7, decimal_places=2, blank=True, null=True)
    numReviews = models.IntegerField(null=True, blank=True, default=0)
    old_price = models.DecimalField(max_digits=11, decimal_places=2)
    discount = models.IntegerField(blank=True, null=True)
    price = models.DecimalField(max_digits=12, decimal_places=2, blank=True, null=True)
    countInStock = models.IntegerField(blank=True, null=True, default=0)
    createdAt = models.DateTimeField(auto_now_add=True)
    short_description = models.CharField(max_length=2000, blank=True, null=True)
    isCampaign = models.BooleanField(blank=True, null=True, default=False)
    _id = models.AutoField(primary_key=True, editable=False)
    

    def save(self, *args, **kwargs):
        self.price = Decimal(self.old_price * (100 - self.discount) / 100)
        return super(Product, self).save(*args, **kwargs)
    

    class Meta:
        ordering = ['-createdAt']


    def __str__(self):
        return self.name

#这是我的序列化器

class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = '__all__'


class SubcategorySerializer(serializers.ModelSerializer):
    category = serializers.SerializerMethodField(read_only=True)

    class Meta:
        model = Subcategory
        fields = '__all__'

    def get_category(self, obj):
        category = obj.category
        serializer = CategorySerializer(category, many=True)
        return serializer.data



class ProductSerializer(serializers.ModelSerializer):
    user = serializers.SerializerMethodField(read_only=True)
    subcategory = serializers.SerializerMethodField(read_only=True)

    class Meta:
        model = Product
        fields = '__all__'

    def get_user(self, obj):
        user = obj.user
        serializer = VendorSerializer(user, many=False)
        return serializer.data

    def get_subcategory(self, obj):
        subcategory = obj.subcategory
        serializer = SubcategorySerializer(subcategory, many=True)
        return serializer.data

Answer 1

You can use model serializers as fields to specify nested relationships.

您将 many=True 传递给了您的 SubcategorySerializer，尽管只有一个子类别，因此它应该是 False

class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = '__all__'


class SubcategorySerializer(serializers.ModelSerializer):
    category = CategorySerializer(read_only=True)

    class Meta:
        model = Subcategory
        fields = '__all__'


class ProductSerializer(serializers.ModelSerializer):
    user = VendorSerializer(read_only=True)
    subcategory = SubcategorySerializer(read_only=True, required=False)

    class Meta:
        model = Product
        fields = '__all__'

'Subcategory' 对象的 Django nestesd 序列化程序问题不可迭代

Django nestesd serializers problem for 'Subcategory' object is not iterable

django

django-serializer

django-rest-framework