Django REST中的PrimaryKeyRelatedField或嵌套关系

我的问题是我想得到这个：

输出

"counter": 1,
"reference": {
   "ref": "a",
   "name": "apple",
   "description": "a fruit"
        },
"stock": 10,

带有PrimaryKeyRelatedField的serializers.py

class StockSerializer(serializers.ModelSerializer):
    counter = serializers.PrimaryKeyRelatedField(queryset=Counter.objects.all())
    reference = serializers.PrimaryKeyRelatedField(queryset=Reference.objects.all())
    
    class Meta:
        model = Stock
        fields = ['counter', 'reference', 'stock']

serializers.py与嵌套关系

class ReferenceSerializer(serializers.ModelSerializer):

    class Meta:
        model = Reference
        fields = ['ref', 'name', 'description']

class StockSerializer(serializers.ModelSerializer):
    counter = serializers.PrimaryKeyRelatedField(queryset=Counter.objects.all())
    reference = ReferenceSerializer()
    
    class Meta:
        model = Stock
        depth = 2
        fields = ['counter', 'reference', 'stock']

---

如果我使用PrimaryKeyRelatedField，我只有id，但是如果我使用嵌套关系，我必须填充所有字段，但它已经存在，我想从列表中选择。您可以有两个字段，一个是只读的，另一个是只读的，如下所示：

class StockSerializer(serializers.ModelSerializer):
    counter = serializers.PrimaryKeyRelatedField(queryset=Counter.objects.all())
    reference = ReferenceSerializer(read_only=True)
    reference_id = serializers.PrimaryKeyRelatedField(queryset=Reference.objects.all(), write_only=True)

---

当API发送数据时，它显示

reference

，当它接收输入时，它获得

reference\u id

您可以有两个字段-一个是只读的，另一个是只读的，如下所示：

class StockSerializer(serializers.ModelSerializer):
    counter = serializers.PrimaryKeyRelatedField(queryset=Counter.objects.all())
    reference = ReferenceSerializer(read_only=True)
    reference_id = serializers.PrimaryKeyRelatedField(queryset=Reference.objects.all(), write_only=True)

当API发送数据时，它显示

reference

，当它接收输入时，它获得

reference\u id