MongoDB with Node.js

import { MongoClient } from 'mongodb';

const client = new MongoClient(process.env.MONGODB_URI ?? 'mongodb://localhost:27017');
await client.connect();
const products = client.db('driver_demo').collection('products');
await products.deleteMany({});

const { insertedIds } = await products.insertMany([
  { name: 'Mug', price: 8.5, stock: 12 },
  { name: 'Lamp', price: 24, stock: 0 },
  { name: 'Pen', price: 1.2, stock: 40 },
]);
console.log(`Inserted ${Object.keys(insertedIds).length} products`);

const inStock = await products
  .find({ stock: { $gt: 0 } }, { projection: { _id: 0, name: 1, price: 1 } })
  .sort({ price: -1 })
  .toArray();
console.log(inStock);

const { modifiedCount } = await products.updateOne({ name: 'Lamp' }, { $inc: { stock: 5 } });
const lamp = await products.findOne({ name: 'Lamp' }, { projection: { _id: 0, stock: 1 } });
console.log(modifiedCount, lamp);

const [summary] = await products.aggregate([
  { $group: { _id: null, items: { $sum: '$stock' }, avgPrice: { $avg: '$price' } } },
  { $project: { _id: 0, items: 1, avgPrice: { $round: ['$avgPrice', 2] } } },
]).toArray();
console.log(summary);

await client.close();

import { MongoClient, ObjectId } from 'mongodb';

const client = new MongoClient(process.env.MONGODB_URI ?? 'mongodb://localhost:27017');
await client.connect();
const users = client.db('driver_demo').collection('users');
await users.deleteMany({});
await users.createIndex({ email: 1 }, { unique: true });

const { insertedId } = await users.insertOne({ email: 'ada@example.com', name: 'Ada' });
const idFromUrl = insertedId.toHexString();

async function findUser(id) {
  if (!ObjectId.isValid(id)) return 'invalid id';
  const user = await users.findOne({ _id: new ObjectId(id) }, { projection: { _id: 0, name: 1 } });
  return user ?? 'not found';
}
console.log(await findUser(idFromUrl));
console.log(await users.findOne({ _id: idFromUrl }));
console.log(await findUser('not-an-id'));
console.log(await findUser('64b7f3c2a1b2c3d4e5f60718'));

try {
  await users.insertOne({ email: 'ada@example.com', name: 'Another Ada' });
} catch (err) {
  console.log(err.code === 11000 ? '409 Conflict: email already registered' : err.message);
}
await client.close();

import express from 'express';
import { MongoClient, ObjectId } from 'mongodb';

const client = new MongoClient(process.env.MONGODB_URI ?? 'mongodb://localhost:27017');
await client.connect();
const notes = client.db('driver_demo').collection('notes');
await notes.deleteMany({});

const app = express();
app.use(express.json());

app.post('/notes', async (req, res) => {
  if (typeof req.body.text !== 'string' || !req.body.text.trim()) return res.status(400).json({ error: 'text is required' });
  const doc = { text: req.body.text.trim(), createdAt: new Date() };
  const { insertedId } = await notes.insertOne(doc);
  res.status(201).json({ id: insertedId, text: doc.text });
});

app.get('/notes/:id', async (req, res) => {
  if (!ObjectId.isValid(req.params.id)) return res.status(400).json({ error: 'Bad id' });
  const note = await notes.findOne({ _id: new ObjectId(req.params.id) }, { projection: { _id: 0, text: 1 } });
  note ? res.json(note) : res.status(404).json({ error: 'Not found' });
});

const server = app.listen(0, async () => {
  const base = `http://localhost:${server.address().port}/notes`;
  const created = await (await fetch(base, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ text: ' Buy milk ' }) })).json();
  console.log(created.text, typeof created.id);
  console.log(await (await fetch(`${base}/${created.id}`)).text());
  console.log((await fetch(`${base}/abc`)).status, (await fetch(`${base}/64b7f3c2a1b2c3d4e5f60718`)).status);
  server.close();
  await client.close();
});