更新Mongoose对象

const mongoose = require('mongoose');

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

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

const user = new User({
  name: 'John',
  age: 25,
  email: 'john@example.com'
});

user.save()
  .then(() => {
    console.log('User saved successfully');
  })
  .catch((error) => {
    console.error('Error saving user:', error);
  });

User.findOneAndUpdate({ name: 'John' }, { age: 26 })
  .then(() => {
    console.log('User updated successfully');
  })
  .catch((error) => {
    console.error('Error updating user:', error);
  });

User.findOneAndUpdate({ name: 'John' }, { age: 26, email: 'newemail@example.com' })
  .then(() => {
    console.log('User updated successfully');
  })
  .catch((error) => {
    console.error('Error updating user:', error);
  });