NodeJS – 获取Mongodb的属性在连接时不工作

我是NodeJS和ExpressJS的新手。 我正在按照这个教程http://cwbuecheler.com/web/tutorials/2013/node-express-mongo/来创build和连接mongodb和nodejs。 一切工作正常（数据库数据插入通过命令行，package.jsonconfiguration）除了数据库连接，它会引发undefined error 。

 var monk = require('monk'); var db = monk('localhost:27017/deno'); 

我在控制台中检查这个console.log(db)它显示index.js 'undefined'

我的app.js是：

 var express = require('express'); var path = require('path'); var favicon = require('serve-favicon'); var logger = require('morgan'); var cookieParser = require('cookie-parser'); var bodyParser = require('body-parser'); // New Code var mongo = require('mongodb'); var monk = require('monk'); var db = monk('localhost:27017/Fujitsu'); var routes = require('./routes/index'); var users = require('./routes/users'); var app = express(); // view engine setup app.set('views', path.join(__dirname, 'views')); app.set('view engine', 'jade'); // uncomment after placing your favicon in /public //app.use(favicon(path.join(__dirname, 'public', 'favicon.ico'))); app.use(logger('dev')); app.use(bodyParser.json()); app.use(bodyParser.urlencoded({ extended: false })); app.use(cookieParser()); app.use(express.static(path.join(__dirname, 'public'))); // Make our db accessible to our router app.use(function(req,res,next){ req.db = db; next(); }); app.use('/', routes); app.use('/users', users); // catch 404 and forward to error handler app.use(function(req, res, next) { var err = new Error('Not Found'); err.status = 404; next(err); }); // error handlers // development error handler // will print stacktrace if (app.get('env') === 'development') { app.use(function(err, req, res, next) { res.status(err.status || 500); res.render('error', { message: err.message, error: err }); }); } // production error handler // no stacktraces leaked to user app.use(function(err, req, res, next) { res.status(err.status || 500); res.render('error', { message: err.message, error: {} }); }); module.exports = app; 

routes / index.js是

 var express = require('express'); var router = express.Router(); /* GET home page. */ router.get('/', function(req, res, next) { res.render('index', { title: 'Express' }); }); /************ Customized starts Here **********/ /* GET Userlist page. */ router.get('/userlist', function(req, res) { var db = req.db; console.log(db); var collection = db.get('usercollection'); collection.find({},{},function(e,docs){ res.render('userlist', { "userlist" : docs }); }); }); /******** Customized - Ends here ***********/ module.exports = router; 

请任何人告诉我的解决scheme，因为现在我正在努力与此。

提前致谢。