如何在mongoose中使用"find()“和populate字段？

const mongoose = require('mongoose');

// 定义模型
const UserSchema = new mongoose.Schema({
  name: String,
  posts: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Post' }]
});

const PostSchema = new mongoose.Schema({
  title: String,
  content: String
});

const User = mongoose.model('User', UserSchema);
const Post = mongoose.model('Post', PostSchema);

// 查询用户及其关联的文章
User.find({})
  .populate('posts')
  .exec((err, users) => {
    if (err) {
      console.error(err);
      return;
    }

    users.forEach(user => {
      console.log('User:', user.name);
      console.log('Posts:');
      user.posts.forEach(post => {
        console.log('- Title:', post.title);
        console.log('  Content:', post.content);
      });
    });
  });