如何将中间模型中的字段序列化为多对多关系的主模型？

# models.py
from django.db import models

class IntermediateModel(models.Model):
    # 定义中间模型的字段
    field1 = models.CharField(max_length=100)
    field2 = models.IntegerField()

class MainModel(models.Model):
    # 定义多对多关系
    intermediates = models.ManyToManyField(IntermediateModel)

# serializers.py
from rest_framework import serializers
from .models import IntermediateModel, MainModel

class IntermediateSerializer(serializers.ModelSerializer):
    class Meta:
        model = IntermediateModel
        fields = '__all__'

class MainSerializer(serializers.ModelSerializer):
    intermediates = IntermediateSerializer(many=True)

    class Meta:
        model = MainModel
        fields = '__all__'

    def create(self, validated_data):
        intermediates_data = validated_data.pop('intermediates')
        main_model = MainModel.objects.create(**validated_data)
        for intermediate_data in intermediates_data:
            IntermediateModel.objects.create(main_model=main_model, **intermediate_data)
        return main_model

    def update(self, instance, validated_data):
        intermediates_data = validated_data.pop('intermediates')
        intermediates = instance.intermediates.all()
        intermediates = list(intermediates)
        instance.field1 = validated_data.get('field1', instance.field1)
        instance.field2 = validated_data.get('field2', instance.field2)
        instance.save()

        for intermediate_data in intermediates_data:
            intermediate = intermediates.pop(0)
            intermediate.field1 = intermediate_data.get('field1', intermediate.field1)
            intermediate.field2 = intermediate_data.get('field2', intermediate.field2)
            intermediate.save()

        return instance