mongoose按带条件的填充字段对文档进行排序

const mongoose = require('mongoose');

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

const postSchema = new mongoose.Schema({
  title: String,
  content: String,
  createdAt: { type: Date, default: Date.now }
});

// 定义模型
const User = mongoose.model('User', userSchema);
const Post = mongoose.model('Post', postSchema);

// 查询用户并填充其关联的文章，并按文章创建时间降序排序
User.findOne({ name: 'John' })
  .populate({
    path: 'posts',
    options: { sort: { createdAt: -1 } }
  })
  .exec((err, user) => {
    if (err) {
      console.error(err);
      return;
    }
    console.log(user);
  });