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error in learn you mongo exercise 3

See original GitHub issue

I’m running from c9.IO, whenever I try to run the selected file with the command “learnyoumongo run file.js” I get the below error.

I tried playing around with the code and I tried it with a blank file, the result is always the same…

/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/mongodb/lib/server.js:235
        process.nextTick(function() { throw err; })
                                      ^

TypeError: Cannot read property 'collection' of undefined
    at Exercise.<anonymous> (/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/exercises/find/exercise.js:37:5)
    at next (/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/workshopper-exercise/exercise.js:260:17)
    at Exercise.end (/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/workshopper-exercise/exercise.js:266:5)
    at Workshopper.end (/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/workshopper/workshopper.js:191:12)
    at Workshopper.done (/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/workshopper/workshopper.js:323:19)
    at Exercise.<anonymous> (/home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/workshopper-exercise/exercise.js:149:14)
    at /home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/workshopper-exercise/exercise.js:136:16
    at /home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/exercises/find/exercise.js:20:21
    at /home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/mongodb/lib/mongo_client.js:269:20
    at /home/ubuntu/.nvm/versions/node/v4.1.1/lib/node_modules/learnyoumongo/node_modules/mongodb/lib/db.js:226:14

Issue Analytics

State:
Created 8 years ago
Comments:16 (4 by maintainers)

Top GitHub Comments

2reactions

evanlucascommented, Jun 9, 2016

@ThomastheBicyclist you would need to run npm install mongodb whenever you see that error

1reaction

mahdiASCcommented, Apr 17, 2018

Was having same issue and this helped: https://stackoverflow.com/questions/47662220/db-collection-is-not-a-function-when-using-mongoclient-v3-0/47662979

Essentially, the newer version of mongodb has changed how the .connect() method works. It no longer provides a db, but a Client object. You can extract the db from this object by referring to the db by name. For example:

const mongo = require("mongodb").MongoClient;
const url = "mongodb://localhost:27017/learnyoumongo";
const database = "learnyoumongo";
const ageThresh = parseInt(process.argv[2]);

mongo.connect(url, function (err, client) {
    if (err) throw err;
    const col = client.db(database).collection("parrots");
    col.find({
        age: {$gt:ageThresh}
    }).toArray(function (err, docs) {
            if (err) throw err;
            console.log(docs);
        })
    client.close();
});

Note how you close the client now, and not the db