如何在mongoose中使用map运算符

npm install mongoose

const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true });

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

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

User.find({}, (err, users) => {
  if (err) {
    console.error(err);
  } else {
    const updatedUsers = users.map(user => {
      user.age += 1;
      return user;
    });

    console.log(updatedUsers);

    // 更新数据库中的用户数据
    User.updateMany({}, { $set: { age: updatedUsers.map(user => user.age) } }, (err, result) => {
      if (err) {
        console.error(err);
      } else {
        console.log('Users updated successfully');
      }
    });
  }
});