问在mongodb中上传图像时出现错误，无法读取未定义的属性'buffer‘

EN

const express=require('express');
const multer=require('multer');
const getstream = require('get-stream');
const resume=require('../model/Resume')

const router = new express.Router();
const uplaod = multer({

    limits:{
      fileSize: 100000
    },

    fileFilter(req,file,cb)
    {
      if(!file.originalname.endsWith('pdf'))
      {
        return cb(new Error('Upload the pdf file'))
      }

      cb(undefined,true);
    }
  });
router.post('/Resume',uplaod.single('avatar'),async (req,res)=>{


     req.resume.avatar=req.file.buffer
      await req.resume.save();
      res.send({sucess:'sucess'});
    },(error,req,res,next)=>{

      //It is used for print message otherwise it will give long html message

      res.status(404).send({error:error.message});
    })



  module.exports=router;