使用mongo或mongoose和node.js将字符串值聚合到每个字段的唯一字符串值数组中

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const userSchema = new Schema({
  name: String,
  email: String
});

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

mongoose.connect('mongodb://localhost/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true })
  .then(() => {
    console.log('Connected to MongoDB');
    
    User.aggregate([
      { $group: { _id: null, names: { $addToSet: '$name' }, emails: { $addToSet: '$email' } } }
    ])
    .then(result => {
      console.log('Aggregation result:', result);
    })
    .catch(error => {
      console.error('Aggregation error:', error);
    })
    .finally(() => {
      mongoose.disconnect();
    });
  })
  .catch(error => {
    console.error('MongoDB connection error:', error);
  });