如何正确地在mongoose中使用ObjectId

const mongoose = require('mongoose');
const { Schema } = mongoose;

const userSchema = new Schema({
  name: String,
  email: String,
  posts: [{ type: Schema.Types.ObjectId, ref: 'Post' }] // 引用Post集合中的文档
});

const postSchema = new Schema({
  title: String,
  content: String,
  author: { type: Schema.Types.ObjectId, ref: 'User' } // 引用User集合中的文档
});

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

async function run() {
  await mongoose.connect('mongodb://localhost:27017/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true });

  const newUser = new User({ name: 'John Doe', email: 'john@example.com' });
  await newUser.save();

  const newPost = new Post({ title: 'My First Post', content: 'Hello World!', author: newUser._id });
  await newPost.save();

  // 查询用户及其帖子
  const userWithPosts = await User.findById(newUser._id).populate('posts');
  console.log(userWithPosts);

  await mongoose.disconnect();
}

run().catch(console.error);

const isValid = mongoose.Types.ObjectId.isValid(someValue);
if (!isValid) {
  console.error('Invalid ObjectId');
}