如何使MongoClient在node js rest API中的所有页面中全局可用

npm install mongodb

const MongoClient = require('mongodb').MongoClient;

global.mongoClient = null;

const url = 'mongodb://localhost:27017'; // MongoDB连接URL
const dbName = 'your-database-name'; // 数据库名称

MongoClient.connect(url, { useNewUrlParser: true }, (err, client) => {
  if (err) {
    console.error('Failed to connect to MongoDB:', err);
  } else {
    console.log('Connected to MongoDB successfully');
    global.mongoClient = client.db(dbName);
  }
});

const express = require('express');
const router = express.Router();

router.get('/users', (req, res) => {
  const collection = global.mongoClient.collection('users');
  // 执行数据库操作...
});

module.exports = router;