使用两个“兄弟”模型创建嵌套序列化程序答案

【问题标题】：Creating a Nested Serializer with two "Sibling" Models使用两个“兄弟”模型创建嵌套序列化程序
【发布时间】：2021-04-24 23:43:41
【问题描述】：

我正在尝试获得与此类似的 JSON 输出：

{
    name: John Doe,
    best_buy_price: 420,
    best_sell_price: 69,
    player_profile: {
        tsn_link: https://a_link.com
    }
    playerlistingadvanced: { # This is where I'm having the issue
        sales_minute: 7,
    }
}

我有三个模型。 playerProfile 是“主要”模型，playerListing 和 playerListingAdvanced 通过一对一的关系连接到 playerProfile。 playerPfofile 将有自己的端点，但我还想创建一个端点，主要是列表和高级列表数据（如上所示）。

这是 model.py 文件的精简版：

class PlayerProfile(models.Model):
    card_id = models.CharField(max_length=120, unique=True, primary_key=True)
    name = models.CharField(max_length=420, null=True)
    tsn_link = models.CharField(max_length=420, null=True)
   
 
class PlayerListing(models.Model):
    player_profile = models.OneToOneField(
        PlayerProfile,
        on_delete=models.CASCADE,
        null=True)
    name = models.CharField(max_length=420, null=True)
    best_sell_price = models.IntegerField(null=True)
    best_buy_price = models.IntegerField(null=True)


class PlayerListingAdvanced(models.Model):
    player_profile = models.OneToOneField(
        PlayerProfile,
        on_delete=models.CASCADE,
        null=True)
    sales_minute = models.DecimalField(max_digits=1000, decimal_places=2, null=True)

这是我尝试过的serializer.py，但还没有开始工作。

class PlayerListingAdvancedForNestingSerializer(serializers.ModelSerializer):
    class Meta:
        model = PlayerListingAdvanced
        fields = (
            'sales_minute',
            'last_week_average_buy',
            'last_week_average_sell',
        )

class PlayerListingSerializer(serializers.ModelSerializer):
    player_profile = PlayerProfileForListingSerializer() # works
    playerlistingadvanced = PlayerListingAdvancedForNestingSerializer() #doesn't work
    
    class Meta:
        model = PlayerListing
        fields = (
            'name',
            'best_sell_price',
            'best_buy_price',
            'playerlistingadvanced',
            'player_profile'
        )

我假设因为 playerListing 和 playerListingAdvanced 没有直接关系，所以我需要做一些其他事情来完成这项工作。有人能指出我正确的方向吗？

【问题讨论】：

标签： django serialization django-rest-framework

【解决方案1】：

您可以使用SerializerMethodField。你的假设是正确的。试试这个：

class PlayerListingSerializer(serializers.ModelSerializer):
    player_profile = PlayerProfileForListingSerializer()
    playerlistingadvanced = serializers.SerializerMethodField() 

    class Meta:
        model = PlayerListing
        fields = (
            'name',
            'best_sell_price',
            'best_buy_price',
            'playerlistingadvanced',
            'player_profile'
        )

    def get_playerlistingadvanced(self, obj: PlayerListing):
        player_profile = obj.player_profile
        if hasattr(player_profile, 'playerlistingadvanced'):
            serializer = PlayerListingAdvancedForNestingSerializer(instance=player_profile.playerlistingadvanced)
            return serializer.data
        return None

【讨论】：