DRF - 序列化具有多个外键的模型

Question

我正在 Django 中处理 CRUD API，我需要序列化一个模型，该模型在两个表中都有外键。该模型在两个一对多关系的 'many' 端，我真的没有看到在这个模型中指定关系的任何其他方式（我是 python 和 Django 的新手，我是使用 Django-Rest-Framework 创建 API)

那么，我有两个问题：

1 - Is it a good Idea to have multiple foreign keys in my model or I should refractor my relationships some other way?

2 - If it is fine to have multiple foreign keys in a single model, how do I serialize the model to return the proper JSON?

我的模型是这样的（多了几个字段）：

class DataSource(models.Model):
    datasource_name = models.CharField(max_length=50, unique=True)
    datasource_description = models.CharField(max_length=100)
    ...

class Campaign(models.Model):
    name = models.CharField(max_length=200)
    subject = models.CharField(max_length=200)
    sender = models.EmailField(max_length=200)
    ...

class CampaignDeliveries(models.Model):
    campaign_id = models.ForeignKey(Campaign)
    datasource_id = models.ForeignKey(DataSource)
    delivery_reference_id = models.CharField(max_length=200, primary_key=True)
    date_sent = models.DateTimeField()

交付记录引用了进行交付的活动以及为该交付选择的数据源。

必须以如下格式返回数据：

{
    campaign_id: 001,
    datasource_id: 002,
    datasource_name: "Data Source Name",
    campaign_name: "Campaign Name"
    setup_date:"<Setup Date>",
    delivery_history:[{
        delivery_reference_id:DL_001,
        sender : "abc@xyz.com",
        subject : "Subject",
        sent_on : "<Date>"
    },
    {
        delivery_reference_id:DL_002,
        sender : "abc@xyz.com",
        subject : "Subject",
        sent_on : "<Date>"
    },
    {
        delivery_reference_id:DL_003,
        sender : "abc@xyz.com",
        subject : "Subject",
        sent_on : "<Date>"
    }
    ....
    ]
}

datasource_id 和 campaign_id 字段是 django 在创建记录时给记录的默认 ID，delivery_reference_id 是在创建交付记录时分配的自定义 ID .

希望我已经说清楚了。不过有什么不明白的请追问。

Answer 1

1) 你认为如何根据自己的逻辑对模型进行 FK，但在这个例子中，这是我的方式。

2) 这是答案：

默认情况下，您必须为主模型的每个 FK 命名 related_name。

models.py

class CampaignDeliveries(models.Model):
    delivery_reference_id = models.CharField(max_length=200, primary_key=True)
    date_sent = models.DateTimeField()


class DataSource(models.Model):
    datasource_name = models.CharField(max_length=50, unique=True)
    datasource_description = models.CharField(max_length=100)
    campain_id = models.ForeignKey(CampaignDeliveries, related_name='data_source')

class Campaign(models.Model):
    name = models.CharField(max_length=200)
    subject = models.CharField(max_length=200)
    sender = models.EmailField(max_length=200)
    campain_id = models.ForeignKey(CampaignDeliveries, related_name='campaign_source')

serialiers.py

class DataSourceSerilaizer(serializers.ModelSerializer)

    class Meta:
        model = DataSource
        fileds = '__all__'


class CampaignSerilaizer(serializers.ModelSerializer)

    class Meta:
        model = Campaign
        fileds = '__all__'


class CampaignDeliveriesSerilaizer(serializers.ModelSerializer):

    campaign_source = CampaignSerilaizer(many=True)
    data_source = DataSourceSerilaizer(many=True)

    class Meta:
        model = CampaignDeliveries
        fileds = '__all__'

viwes.py

qv = CampaignDeliveries.objects.all()
serializer = CampaignDeliveriesSerilaizer(qv)
print (serializer.data)

Answer 2

通常你会这样命名你的 ForeignKey 字段：

class CampaignDelivery(models.Model):
    campaign = models.ForeignKey('Campaign')

字段 campaign_id 是自动添加的，是对存储活动 ID 的 table 字段的引用。我可以经常派上用场。所以 CampaignDelivery.campaign returns django 对象和 CampaignDelivery.campaign_id returns 引用活动的 ID。

在一个模型中有多个外键没有错，但我不确定你想在这里完成什么。我认为您需要获取 Campaign 数据及其交付历史记录。您提供的响应示例对此并不是很好，因为它暗示一次交付可以分配给多个活动（这不是真的，因为您有 ForeignKey）。您可以这样完成：

from rest_framework import serializers

class CampaignDeliverySerializer(serializers.ModelSerializer):

    class Meta:
        model = CampaignDelivery
        fields = ('date_sent', 'datasource_id', 'delivery_reference_id', 'datasource__datasource_name', ...)

class CampaignSerializer(serialziers.ModelSerializer):
    delivery_history = CampaignDeliverySerializer(
                           source='campaigndeliveries_set', 
                           many=True
                       )

    class Meta:
        model = Campaign
        fields = ('id', 'name', 'sender', 'subject', 'delivery_history', ...)

示例响应：

{
    'campaign': {
        'id': 123,
        'name': 'Best campaign name evar',
        'sender': 'foo@bar.com',
        'subject': 'Campaign subject',
        'delivery_history': [
            {
                'date_sent': '2017-02-22',
                'datasource_id': 321,
                'delivery_reference_id': 'DL_001',
                'datasource__datasource_name': 'Datasource name'
            },
            ...
        ]
    }
}

DRF - 序列化具有多个外键的模型

DRF - Serializing a model with multiple foreign Keys

python

django

relationship

django-rest-framework

models.py

serialiers.py

viwes.py