如何在Django Rest框架的post方法中添加外键字段

from django.db import models

class ForeignKeyModel(models.Model):
    # 外键模型的字段

class MainModel(models.Model):
    foreign_key = models.ForeignKey(ForeignKeyModel, on_delete=models.CASCADE)
    # 主模型的其他字段

from rest_framework.views import APIView
from rest_framework.response import Response

class MainModelView(APIView):
    def post(self, request):
        foreign_key_id = request.data.get('foreign_key_id')  # 假设外键字段的名称为foreign_key_id
        try:
            foreign_key = ForeignKeyModel.objects.get(id=foreign_key_id)
        except ForeignKeyModel.DoesNotExist:
            return Response({'error': 'Invalid foreign key id'}, status=400)
        
        # 创建主模型实例并保存
        main_model = MainModel(foreign_key=foreign_key)
        main_model.save()
        
        return Response({'success': 'Main model created'}, status=201)