Mongoose findOne callback gives me null

问题

In the code below obj receives null in the findOne callback. Don't understand why. In my database it looks like this.

MongoDB shell version: 2.2.0
connecting to: test
> use test
switched to db test
> db.Restaurant.findOne();
{
    "_id" : ObjectId("53372f9714b4d69cbfa2bbaf"),
    "name" : "Printz",
    "visit" : "2014-04-02 19:00:00"
}

Code app.js

/**
 * Module dependencies.
 */

var express = require('express');
var http = require('http');
var path = require('path');
var moment = require('moment');

var mongoose = require('mongoose');

var app = express();

app.set('port', process.env.PORT || 3000);
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
app.use(express.favicon());
app.use(express.logger('dev'));
app.use(express.json());
app.use(express.urlencoded());
app.use(express.methodOverride());
app.use(app.router);
app.use(express.static(path.join(__dirname, 'public')));

// development only
if ('development' == app.get('env')) {
  app.use(express.errorHandler());
}

var connection = mongoose.connection;

connection.on('error', console.error);

connection.once('open', function() {
    console.log("open!");
});

console.log("Open database")

mongoose.connect('mongodb://localhost/test');

var eventSchema = new mongoose.Schema({
    name: String,
    visit: Date
});

var Restaurant = mongoose.model('Restaurant', eventSchema);

app.get('/', function(req, res) {
    Restaurant.findOne({}, function(err, obj) {
        if (err || !obj) {
            res.send(500);
            console.log("error: " + err + ", obj: " + obj);
            return;
        }

        console.log("obj: " + obj);

        res.render('index', {
            name: obj.name
        });
    });
});

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

回答1:

Yet another victim of mongoose auto-pluralization of collection names. Mongoose is querying the collection 'Restaurants' instead of 'Restaurant'.

var eventSchema = new mongoose.Schema({
  name: String,
  visit: Date
}, {collection: 'Restaurant'}); //override default collection name

var Restaurant = mongoose.model('Restaurant', eventSchema);

For details see the docs on mongoose.Model and util.toCollectionName.

来源：https://stackoverflow.com/questions/22828053/mongoose-findone-callback-gives-me-null

标签

node.js

express

mongoose