节点和远程mongohq连接

Question

我在连接我的mongohq数据库时遇到了很大的问题。我遵循本教程，但使用远程mongoHQ db：http://coenraets.org/blog/2012/10/creating-a-rest-api-using-node-js-express-and-mongodb/替换本地mongo DB

wines.js

var mongo = require('mongodb'); 
Db = mongo.Db;
BSON = mongo.BSONPure;
con = null;

server = new Server('troup.mongohq.com', 'mongo_port', {auto_reconnect: true});
DBCon = new Db('dev', server, {safe: false});
DBCon.open(function(err, db) {
  if(!err) {
   db.authenticate('username', 'password', function(err){
    if(!err) con = db;
   })
  }
 })

// exports.findById = function(req, res) {
//     var id = req.params.id;
//     console.log('Retrieving wine: ' + id);
//     db.collection('wines', function(err, collection) {
//         collection.findOne({'_id':new BSON.ObjectID(id)}, function(err, item) {
//             res.send(item);
//         });
//     });
// };

server.js

var express = require('express'),
path = require('path'),
http = require('http'),
wine = require('./routes/wines');

var app = express();

app.configure(function () {
app.set('port', process.env.PORT || 3000);
app.use(express.logger('dev'));  /* 'default', 'short', 'tiny', 'dev' */
app.use(express.bodyParser()),
app.use(express.static(path.join(__dirname, 'public')));
});

app.get('/wines', wine.findAll);
app.get('/wines/:id', wine.findById);
app.post('/wines', wine.addWine);
app.put('/wines/:id', wine.updateWine);
app.delete('/wines/:id', wine.deleteWine);

http.createServer(app).listen(app.get('port'), function () {
console.log("Express server listening on port " + app.get('port'));
});

尝试启动节点时获取im时出错：

/Sites/nodecellar/routes/wines.js:31
db.open(function(err, db) {
^
ReferenceError: db is not defined
    at Object.<anonymous> (/Sites/nodecellar/routes/wines.js:31:1)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/Sites/nodecellar/server.js:4:12)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)

对这里的错误有什么建议吗？

Answer 1

您的问题几乎可以肯定是与服务器连接设置有关。本教程早于对驱动程序的更新，该驱动程序使接口在所有平台上统一，公认的方法是使用MongoClient类进行设置。

查看URL连接格式上的注释，因为您可能需要传入凭据和数据库才能连接到该格式。