Outdated MongoDB Driver API

[AhmedTareek]

MDN URL

https://developer.mozilla.org/en-US/docs/Learn_web_development/Extensions/Server-side/Express_Nodejs/Introduction

What specific section or headline is this issue about?

using_databases

What information was incorrect, unhelpful, or incomplete?

const { MongoClient } = require("mongodb");

MongoClient.connect("mongodb://localhost:27017/animals", (err, client) => {
  if (err) throw err;

  const db = client.db("animals");
  db.collection("mammals")
    .find()
    .toArray((err, result) => {
      if (err) throw err;
      console.log(result);
      client.close();
    });
});

What did you expect to see?

The callback-based MongoClient.connect method is deprecated in newer versions of the MongoDB, So I expected code which uses the modern API (Async/Await)

Do you have any supporting links, references, or citations?

No response

Do you have anything more you want to share?

No response

MDN metadata

Page report details

• Folder: en-us/learn_web_development/extensions/server-side/express_nodejs/introduction
• MDN URL: https://developer.mozilla.org/en-US/docs/Learn_web_development/Extensions/Server-side/Express_Nodejs/Introduction
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/learn_web_development/extensions/server-side/express_nodejs/introduction/index.md
• Last commit: 8443cb3
• Document last modified: 2025-07-18T00:38:58.000Z

[hamishwillee]

Thanks @AhmedTareek

I don't particularly consider this a defect because as the docs says:

The example below (from the Express documentation) shows how you can find "mammal" records using MongoDB (version 3.0 and up):

The relevant documentation is https://expressjs.com/en/guide/database-integration.html#mongodb and as you see, that is still the mongoDb recommendation.

That said, if you would like to create a PR to fix this, we would accept it because, as you say, it is better to use modern syntax where it is supported. Would you like to create such a PR?

[AhmedTareek]

I believe what the docs on Express mean is only using version 3, not version 3 and up. The docs on MongoDB (https://github.com/mongodb/node-mongodb-native/blob/HEAD/etc/notes/CHANGES_5.0.0.md#optional-callback-support-migrated-to-mongodb-legacy) state:

Node.js driver v5 drops support for callbacks in favor of a Promise-only API.

They even created a legacy repo for callback support (https://github.com/mongodb-js/nodejs-mongodb-legacy#readme). Additionally, the code I mentioned above didn't work when I tried to run it with mongodb@6.18.0 and Node.js v22.11.0.

[hamishwillee]

Thanks @AhmedTareek - in that case, good point, if it doesn't work then it is a defect for sure. Would you like to create a PR for this?

[AhmedTareek]

Yes, let's fix it.