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JavaScript Build a REST API With Express Modeling Data for the API Connecting Mongoose to MongoDB

Posted by John Shockey
John Shockey
45,061 Points

[SOLVED] TypeError: db.on is not a function

Hey,

I am receiving the following error when I run 'node mongoose_sandbox.js' in terminal.

db.on("error", function(err){
   ^

TypeError: db.on is not a function
    at Object.<anonymous> (/Users/johnshockey/Documents/Treehouse/qa-rest-api/mongoose_sandbox.js:9:4)
    at Module._compile (module.js:413:34)
    at Object.Module._extensions..js (module.js:422:10)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Function.Module.runMain (module.js:447:10)
    at startup (node.js:141:18)
    at node.js:933:3

I followed the docs as well and I still get the same error. http://mongoosejs.com/docs/

Yes, everything was installed correctly.

Jonathan Ankiewicz
Jonathan Ankiewicz
17,901 Points

It will help if you post your mongoose_sandbox.js file as well?

In the video you are instructed to call:

db.on('error', function(err){
    console.error("connection error;", error);
});

error actually needs to be err:

db.on('error', function(err){
    console.error("connection error;", err);
});

*also, the video doesn't mention that you need to start the database before you can run your test. But you need to.

In order to start the mongodb database open the terminal in your project folder and write:

mongod

Than run your:

node mongoose_sandbox.js

1 Answer

John Shockey
John Shockey
45,061 Points

Thanks Jonathan,

I went to the actual mongoose docs and did end up changing it from 'error' to 'err,' however, that still didn't solve my issue.

But the following change finally resolved the error:

var db = mongoose.connection;

I changed 'mongoose.connect' to 'mongoose.connection'