MongoDB - Error: invalid schema, expected mongodb

Question

I\'m new in building application with MEAN Stack, I\'m trying to build a real time chat app, here is my server side :

console.log(\"Server running...!\");

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Answer 1

I just had this issue as well and it was because I had the protocol wrong:

mongo://localhost:27017/test

The protocol being wrong can also cause this error. It should be like this:

mongodb://localhost:27017/test

Answer 2

Might seem obvious, but you'll also encounter this error when you pass invalid values in general to the mongo client, e.g. undefined. Ran into this when I was referencing the wrong key on a config object.

Answer 3

Sometimes, error might be with the quotes around environment variables. Remove them once and try. Might help.

Error might be with :

 set DATABASE_URI='mongodb://localhost:1000/my_app' && node index.js

Correct command will be:

  set DATABASE_URI=mongodb://localhost:1000/my_app && node index.js

Answer 4

Change content of this line from

mongo.connect('localhost:27017/db/chat',function(err,db)

to

mongo.connect('mongodb://localhost:27017/db/chat',function(err,db)

Then you can connect MongoDB database successfully.

Answer 5

the working code would be like this

don't forget to replace username, password & URL

const socketClient = require('socket.io').listen(4000).sockets;
const MongoClient = require('mongodb').MongoClient;

const uri = "mongodb+srv://<username>:<password>@cluster0-saugt.mongodb.net/test?retryWrites=true&w=majority";

const client = new MongoClient(uri, { useNewUrlParser: true });
client.connect(err => {
    socketClient.on('connection', function (socket) {

        //Need to Get the Database first before trying to access the collections.
        let chat = client.db("test").collection('chats');

        // Get chats from mongo collection
        // perform actions on the collection object
        chat.find().limit(100).sort({ _id: 1 }).toArray(function (err, res) {
            if (err) {
                throw err;
            }

            // Emit the messages
            socket.emit('output', res);
        });


    });

});

Answer 6

update your mongodb npm version