Mongoose，如果查询返回的文档字段数组中有ObjectId，则填充布尔变量

const mongoose = require('mongoose');

// 定义数据模型
const userSchema = new mongoose.Schema({
  name: String,
  age: Number,
  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);

// 查询用户并填充布尔变量
User.findOne({ name: 'John' })
  .populate('posts')
  .exec((err, user) => {
    if (err) {
      console.error(err);
      return;
    }

    // 填充布尔变量
    const hasObjectId = user.posts.some(post => post._id instanceof mongoose.Types.ObjectId);

    console.log(hasObjectId);
  });