使用mongoose插入或更新到Mongo中，并在更新时修改内部元素

const mongoose = require('mongoose');

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

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

User.create({ name: 'John', age: 25 }, (err, user) => {
  if (err) {
    console.error(err);
  } else {
    console.log('User created:', user);
  }
});

User.updateOne({ name: 'John' }, { age: 30 }, (err, result) => {
  if (err) {
    console.error(err);
  } else {
    console.log('User updated:', result);
  }
});

User.updateOne({ name: 'John' }, { $inc: { age: 1 } }, (err, result) => {
  if (err) {
    console.error(err);
  } else {
    console.log('User updated:', result);
  }
});