find results of attributes in mongodb are always undefined

Question

find results of attributes in mongodb are always undefined

I really really need help in this. I am using node.js with mongodb and mongoose. So far I've managed to create a schema and save those into my database.

var Bericht = new Schema({
    name     : String
  , mail     : String
  , betreff  : String
  , inhalt   : String
  , datum    : Date
});
var Bericht = mongoose.model('Bericht', Bericht);

I habe a html formular where I can transmit with misc. fields data, by querystring I converting those into readable strings

var bericht_data = { 
name: tempo.Name
, mail: tempo.Mail
, betreff: tempo.Betreff
, inhalt: tempo.Inhalt
};
var testoro = new Bericht(bericht_data);
testoro.save(function (err) {
  if (!err) console.log('Success!');
});

so tempo.Name for example is a string and it also successful in saving it. So far I can save all data from this formular into my mongodb.

Now the very problem: I want the data back as string to handle for dynamic html. To get the info into my console, I use

Bericht.find(
{},
{ '_id': 0},
        function(err, docs) {
        if (!err){ 
               console.log(docs);
          // process.exit();
                  }
        else { throw err;}
        }
);

The console gives me all data which was ever saved in my schema Bericht excluding the long _id stuff. Sample output: [ { name: 'Hans', mail: 'hans@wurst.de', betreff: 'I lost my wurst', inhalt: 'look at me, I am amazing' } ] That's just one, normally there would be a huge amount of data. The idea is right now to extract only the name into a string like "Hans". I want to get this name into a var, but hell it seems impossible! I've tried

Bericht.find(
{},
{ '_id': 0},
        function(err, docs) {
        if (!err){ 
               console.log(docs.name);
          // process.exit();
                  }
        else { throw err;}
        }
);

But the I get only "undefined" delivered. I appreciate your help!

node.js
mongodb
mongoose

Answer 1

Take a look at Mongoose QueryStreams. I haven't used it myself, but I've modified their example code to fit your Model, to give you an idea of how it might work in practice:

var stream = Bericht.find().stream()
  , names = []
  , i;

function closeHandler() {
  console.log(JSON.stringify(names));
};

stream.on('data', function (doc) {
  if (doc.name) {
    names.push(doc.name);
  }
})

stream.on('error', function (err) {
  // handle err
})

stream.on('close', closeHandler)

Answer 2

Mongoose find return an array of documents so you should try the following:

Bericht.find(
 {},
 { '_id': 0},
    function(err, docs) {
     if (!err){
        for(var i=0; i<docs.length; i++)
        {
           console.log(docs[i].name);
        }
      // process.exit();
     }
    else { throw err;}
    }
);