Clementine tutorial : "TypeError: db.collection is not a function"

Clementine tutorial : "TypeError: db.collection is not a function"
0
#1

Howdy, campers. I am working through the clementine tutorial (http://www.clementinejs.com/tutorials/tutorial-beginner.html) at the moment (I am using c9.io) when I ran into a bit of a snag.

After doing everything correctly up to about the mid-point of the tutorial, and then double-checking that I had done everything correctly, testing resulted in the following error message: “TypeError: db.collection is not a function”

This actually through me for a loop at first. I could not figure out what I was doing wrong with db.

Turns out, nothing.

I finally came across this solution:

 npm uninstall mongodb --save

 npm install [email protected] --save

Problem was with the library I was using. The above commands worked like a charm and now I no longer get the error.

On to the next bug!

#2

Shouldn’t it will be better if you always just run

npm install mongodb --save

Why would u specified version ? If you don’t specify version you will get the latest one. Unless u want specific version. :slight_smile:

#3

Nope, that causes the error!
I just uninstalled and ran npm install mongodb --save, then ran “node server” and got the error.
Then I repeated npm uninstall mongodb --save … npm install [email protected] --save, then ran “node server” and my application is now running.

Something though tells me it would be far better to be able to run on whatever the latest version is. I obviously need a better understanding of why this is happening. :slight_smile:

#4

Well it’s strange. When I run in my git bash npm install mongodb --save it’s installs perfectly :slight_smile:

#5

Yeah it is strange. Tickle on back of neck says being tied to a certain version is going to cause me problems down the road. Do you have any idea what I might research in order to find out why this is happening?

#6

Try to clear cache ?

#7

I just closed all browser sessions, then ran new session, carried out npm uninstall mongodb --save then npm install mongodb --save

then ran the application with “node server” and am still getting the error. And again when I go back and user npm install [email protected] --save then run the application, there is no error.

Application code is here, btw: https://github.com/olddognewtrix123/clementinetutorial1

#8

What error u get when u run npm install mongodb --save ?
If no error, what displays in package.json file after install ?

#9

olddognewtrix123:~/workspace (master) $ node server
MongoDB successfully connected on port 27017.
/home/ubuntu/workspace/node_modules/mongodb/lib/mongo_client.js:797
throw err;
^

TypeError: db.collection is not a function
at new clickHandler (/home/ubuntu/workspace/app/controllers/clickHandler.server.js:4:20)
at module.exports (/home/ubuntu/workspace/app/routes/index.js:7:21)
at /home/ubuntu/workspace/server.js:25:2
at args.push (/home/ubuntu/workspace/node_modules/mongodb/lib/utils.js:431:72)
at /home/ubuntu/workspace/node_modules/mongodb/lib/mongo_client.js:254:5
at connectCallback (/home/ubuntu/workspace/node_modules/mongodb/lib/mongo_client.js:933:5)
at /home/ubuntu/workspace/node_modules/mongodb/lib/mongo_client.js:794:11
at _combinedTickCallback (internal/process/next_tick.js:73:7)
at process._tickCallback (internal/process/next_tick.js:104:9)

{
“name”: “beginner-app”,
“version”: “1.0.0”,
“description”: ",-----.,–.
“main”: “server.js”,
“scripts”: {
“test”: “echo “Error: no test specified” && exit 1”
},
“author”: “”,
“license”: “MIT”,
“dependencies”: {
“express”: “^4.16.2”,
“mongodb”: “^3.0.0-rc0”
}
}

#10

const myDB=db.db(‘clementinejs’);

This is the answer. U need to use const myDB=db.db('clementinejs'); in your case.
Anyway u will not encounter this error when u will use mongoose which is more fluent. :slight_smile:

#11

Thanks!!

I updated this (which was pretty much what is exactly in the tutorial)

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

if (err) {
	throw new Error('Database failed to connect!');
} else {
	console.log('MongoDB successfully connected on port 27017.');
}

app.use('/public', express.static(process.cwd() + '/public'));
app.use('/controllers', express.static(process.cwd() + '/app/controllers'));

routes(app, db);

app.listen(8080, function () {
	console.log('Listening on port 8080...');
});

});

in my server.js file to this:

 mongo.connect('mongodb://localhost:27017/clementinejs', function (err, client) {

    if (err) {
	throw new Error('Database failed to connect!');
    } else {
	console.log('MongoDB successfully connected on port 27017.');
	var myDB=client.db('clementinejs');
    }

    app.use('/public', express.static(process.cwd() + '/public'));
    app.use('/controllers', express.static(process.cwd() + '/app/controllers'));

    routes(app, myDB);

    app.listen(8080, function () {
	    console.log('Listening on port 8080...');
    	});

 });

and I am now no longer getting the error anymore when running ‘node server’

For the record, this is what now appears in my json file:

"dependencies": {
   "express": "^4.16.2",
   "mongodb": "^3.0.0-rc0"
 }
#12

Perfect :slight_smile: Glad to be able to help :slight_smile:

#13

Had the same problem. Still don’t know the problem with new versions, but this solve the issue.
Thanks @olddognewtrix123 !