MongoDB Node.js Driver

The MongoDB Node.js driver is the library your backend uses to talk to the server. The shell is a client. Compass is a client. mongodb on npm is the client you ship. Mongoose sits on top of this driver — that is a later module. Start with the native API so you know what the ODM is wrapping.

1. 01Node.js route / script
2. 02mongodb driver (MongoClient)
3. 03Database — app
4. 04Collection — users
5. 05findOne / find / insertOne …

import { MongoClient } from "mongodb";

const client = new MongoClient(process.env.MONGO_URI);

await client.connect();

const db = client.db("app");
const users = db.collection("users");

const user = await users.findOne({
  email: "rahul@example.com",
});

{
  _id: ObjectId("64a1b2c3d4e5f6a7b8c90001"),
  name: "Rahul",
  email: "rahul@example.com",
  city: "Bangalore",
  ...
}

• MongoClient — the process-wide client. Holds the connection pool (next lesson).
• client.db("app") — the database. Same idea as use app in the shell.
• db.collection("users") — the collection. Same as db.users.
• findOne — one document or null. find returns a cursor; call toArray() when you want an array.

Shell: db.users.findOne({ city: "Bangalore" }). Driver: users.findOne({ city: "Bangalore" }). Same filter document. CRUD from Node.js later is this API for insert, update and delete.