只存储一个对象的Mongoose填充方法

const mongoose = require('mongoose');

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

const articleSchema = new mongoose.Schema({
  title: String,
  content: String,
  author: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User' // 引用User模型
  },
  // 其他字段...
});

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

const user = new User({
  name: 'John',
  age: 25,
  // 其他字段...
});

const article = new Article({
  title: 'Introduction to Mongoose Populate',
  content: '...',
  author: user._id, // 关联用户文档
  // 其他字段...
});

Article.findOne({ title: 'Introduction to Mongoose Populate' })
  .populate('author') // 填充author字段
  .exec((err, article) => {
    if (err) {
      console.error(err);
    } else {
      console.log(article);
    }
  });