在对象创建时保存多对多字段- Django DRF

from django.db import models

class A(models.Model):
    # 定义A模型的其他字段
    
class B(models.Model):
    a = models.ManyToManyField(A)
    # 定义B模型的其他字段

from rest_framework import serializers

class BSerializer(serializers.ModelSerializer):
    a = serializers.PrimaryKeyRelatedField(queryset=A.objects.all(), many=True, write_only=True)

    class Meta:
        model = B
        fields = '__all__'

    def create(self, validated_data):
        a_data = validated_data.pop('a')
        b = B.objects.create(**validated_data)
        b.a.set(a_data)
        return b

from rest_framework import generics

class BCreateView(generics.CreateAPIView):
    serializer_class = BSerializer