python - 从 Django 模型返回 JSON 格式的子属性

Question

我在 Django 中设置了一个数据库模型来跟踪投资组合，并尝试开发一个 API 来返回投资组合以及其中的每个代币，以及与该代币关联的每笔交易。但是，使用 API 我只能看到返回的模型的名称字段。一些用于澄清的代码:

模型.py:

class Portfolio(models.Model):

    name = models.CharField(max_length=250)
    @property
    def coins(self):
        return Coin.objects.filter(portfolio=self)

    def transactions(self):
        return Transaction.objects.filter(portfolio=self)

    def __str__(self):
        return self.name


class Coin(models.Model):
    portfolio = models.ForeignKey(Portfolio, on_delete=models.PROTECT)
    name = models.CharField(max_length=100)
    symbol = models.CharField(max_length=5)
    price = models.DecimalField(max_digits=20, decimal_places=9)
    info = models.TextField()
    website = models.TextField()
    rank = models.IntegerField()

    def __str__(self):
        return self.name + " - " + self.symbol


class Transaction(models.Model):
    portfolio = models.ForeignKey(Portfolio, on_delete=models.CASCADE)
    coin = models.ForeignKey(Coin, on_delete=models.PROTECT)
    purchaseDate = models.DateTimeField()
    soldDate = models.DateTimeField(default=None, null=True, blank=True)
    amount = models.DecimalField(max_digits=20, decimal_places=3)
    price = models.DecimalField(max_digits=20, decimal_places=9)

    def __str__(self):
        return self.coin.name + " - " + str(self.amount) + " At $" + str(self.price)

我的 json 序列化器:

class PortfolioSerializer(serializers.ModelSerializer):
    class Meta:
        model = Portfolio
        fields = '__all__'

数据如何返回:

 HTTP 200 OK
    Allow: GET, POST, HEAD, OPTIONS
    Content-Type: application/json
    Vary: Accept

    [
        {
            "id": 3,
            "name": "Binance"
        }
    ]

我想要的是在数据集中，在 binance 下它应该显示一个硬币对象列表，其中包含每个硬币的交易列表。

Answer 1

你真的应该阅读Django-Rest-Framework docs :

class Portfolio(models.Model):

    name = models.CharField(max_length=250)
    @property
    def coins(self):
        return Coin.objects.filter(portfolio=self)

    def transactions(self):
        return Transaction.objects.filter(portfolio=self)

    def __str__(self):
        return self.name


class Coin(models.Model):
    portfolio = models.ForeignKey(Portfolio, relared_name="coins" ,on_delete=models.PROTECT)
    name = models.CharField(max_length=100)
    symbol = models.CharField(max_length=5)
    price = models.DecimalField(max_digits=20, decimal_places=9)
    info = models.TextField()
    website = models.TextField()
    rank = models.IntegerField()

    def __str__(self):
        return self.name + " - " + self.symbol

在您的 PortfolioSerializer 中:

class PortfolioSerializer(serializers.ModelSerializer):
    coins = CoinSerializer(many=True, read_only=True)
    class Meta:
        model = Portfolio
        fields = '__all__'

这里应该在PortfolioSerializer上面写一个CoinSerializer，如:

class CoinSerializer(serializers.ModelSerializer):
        class Meta:
            model = Coin
            fields = '__all__'