Django - 带有序列化程序的可选字段

Question

我想在使用序列化程序的 create 方法时自动生成模型的“路径”字段。否则，我希望能够在我的请求中传递此字段，以便稍后对其进行修改。 我还没有找到使模板的单个字段可选的方法。 这是我的模型：

models.py

class Shop(models.Model):
    name = models.CharField(max_length=255)
    category = models.ForeignKey(ShopCategory, on_delete=models.SET_NULL, null=True, blank=True)
    description = models.TextField(blank=True, null=True)
    path = models.CharField(max_length=255, unique=True)
    mustBeLogged = models.BooleanField(default=False)
    deliveries = models.FloatField(default=7)

    def __str__(self):
        return self.name

这是我的代码：

serializer.py

class ShopSerializer(serializers.ModelSerializer):
    class Meta:
        model = Shop
        exclude = ['path']

    def create(self, validated_data):
        path = validated_data["name"].replace(" ", "-").lower()
        path = unidecode.unidecode(path)
        unique = False
        while unique == False:
            if len(Shop.objects.filter(path=path)) == 0:
                unique = True
            else:
                # Generate a random string
                char = "abcdefghijklmnopqrstuvwxyz"
                path += "-{}".format("".join(random.sample(char, 5)))
        shop = Shop.objects.create(**validated_data, path=path)
        shop.save()
        return shop

views.py

def post(self, request):
        """For admin to create shop"""
        serializer = ShopSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data)
        return Response(serializer.errors)

Answer 1

您可以将路径设置为 Null 并在 create 方法中弹出它。这样就不用在exclude中添加了。

class ShopSerializer(serializers.ModelSerializer):
    path = serializers.CharField(allow_blank=True, allow_null=True)
    
    class Meta:
        model = Shop
        fields = '__all__'

    def create(self, validated_data):
        validated_data.pop('path')
        path = validated_data["name"].replace(" ", "-").lower()
        path = unidecode.unidecode(path)
        unique = False
        while unique == False:
            if len(Shop.objects.filter(path=path)) == 0:
                unique = True
            else:
                # Generate a random string
                char = "abcdefghijklmnopqrstuvwxyz"
                path += "-{}".format("".join(random.sample(char, 5)))
        shop = Shop.objects.create(**validated_data, path=path)
        shop.save()
        return shop
    
    def update(self, instance, validated_data):
        #You will have path in validated_data
        #And you may have to check if the values are null
        return super(ShopSerializer, self).update(instance, validated_data)

除此之外，在您的代码中：

while unique == False:
                if len(Shop.objects.filter(path=path)) == 0:

这将是非常昂贵的操作。在每个循环中它都会触发一个查询，我不确定它背后的逻辑，但您可能想要更改它。