nodejs异步瀑布在第二个函数中使用mongoose findOneAndUpdate

const mongoose = require('mongoose');

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

const userSchema = new mongoose.Schema({
  name: String,
  age: Number,
  email: String
});

const User = mongoose.model('User', userSchema);

User.findOneAndUpdate({ name: 'John' }, { age: 30 }, { new: true })
  .then((updatedUser) => {
    console.log('Updated user:', updatedUser);
  })
  .catch((error) => {
    console.error('Error updating user', error);
  });