无法使用multer和mongose更新数据库

// 引入依赖
const express = require('express');
const multer = require('multer');
const mongoose = require('mongoose');

// 创建Express应用
const app = express();

// 连接MongoDB数据库
mongoose.connect('mongodb://localhost/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true })
  .then(() => {
    console.log('Connected to MongoDB');
  })
  .catch((error) => {
    console.error('Failed to connect to MongoDB', error);
  });

// 定义数据模型
const Schema = mongoose.Schema;
const MyModelSchema = new Schema({
  name: String,
  file: String
});
const MyModel = mongoose.model('MyModel', MyModelSchema);

// 配置multer中间件
const storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'uploads/');
  },
  filename: function (req, file, cb) {
    cb(null, file.originalname);
  }
});
const upload = multer({ storage: storage });

// 定义路由
app.post('/upload', upload.single('file'), (req, res) => {
  const { name } = req.body;
  const file = req.file.filename;

  // 创建新的数据对象
  const newData = new MyModel({ name, file });

  // 保存到数据库
  newData.save()
    .then(() => {
      res.send('Data saved successfully');
    })
    .catch((error) => {
      console.error('Failed to save data', error);
      res.status(500).send('Failed to save data');
    });
});

// 启动服务器
app.listen(3000, () => {
  console.log('Server started on port 3000');
});