Question

我有两个模型，我想调用与两个模型中都存在的外键关联的字段值。例如：假设我们有两个模型：

    from django.db import models
    from django.contrib.auth.models import User

    class Bike(models.Model):
        bike_model = models.CharField(max_length=200)
        owner = models.ForeignKey(User,on_delete=models.CASCADE)

    class Car(models.Model):
        car_model = models.CharField(max_length=200)
        owner = models.ForeignKey(User,on_delete=models.CASCADE)

与之相关的序列化器类为：

    from rest_framework import serializers
    from .models import Bike,Car

    class BikeSerializer(serializers.ModelSerializer):
        class Meta:
            model = Bike
            fields = ('bike_model','owner')

    class CarSerializer(serializers.ModelSerializer):
        class Meta:
            model = Car
            fields = ('car_model','owner')

现在，我想在BikeSerializer中添加一个字段，以获取与给定所有者关联的所有汽车。那就是我要进行以下更改：

    class BikeSerializer(serializers.ModelSerializer):
        cars_owned = ???
        class Meta:
            model = Bike
            fields = ('bike_model','owner','cars_owned')

我不知道如何归还所有者拥有的汽车。因此，对于来自序列化器的数据，我需要自行车模型，所有者ID以及所有者拥有的所有汽车ID的列表。

Answer 1

您应该看这个SerializerMethodField。基本上，您需要在BikeSerializer中创建一个方法来返回拥有的汽车。

class BikeSerializer(serializers.ModelSerializer):
        cars_owned = serializers.SerializerMethodField()

        class Meta:
            model = Bike
            fields = ('bike_model','owner','cars_owned')

        def get_cars_owned(self, object):
            # This is your query to get all cars associated
            return object.cars_owned.all()

Answer 2

您可以将seializer添加为字段：

class BikeSerializer(serializers.ModelSerializer):
        cars_owned = CarSerializer(source='owner.car_set', many=True, read_only=True)
        class Meta:
            model = Bike
            fields = ('bike_model','owner','cars_owned')

如何使用rest_framework序列化程序获取链接到给定外来ket字段的所有对象？

2 个答案: