CRUD Operations with MongoDB

const { MongoClient } = require('mongodb');
const url = 'mongodb://localhost:27017';
const dbName = 'myapp';

const client = new MongoClient(url);

async function getCollection() {
  await client.connect();
  const db = client.db(dbName);
  return db.collection('users');
}

Think of CRUD as the basic actions you can do with any data: Create a new record, Read existing records, Update records, and Delete records.

const collection = await getCollection();

const user = {
  name: 'Alice Johnson',
  email: 'alice@example.com',
  age: 28,
  hobbies: ['reading', 'swimming']
};

const result = await collection.insertOne(user);
console.log('Inserted ID:', result.insertedId);

const users = [
  { name: 'Bob', email: 'bob@example.com', age: 35 },
  { name: 'Charlie', email: 'charlie@example.com', age: 42 },
  { name: 'Diana', email: 'diana@example.com', age: 31 }
];

const result = await collection.insertMany(users);
console.log('Inserted count:', result.insertedCount);

const collection = await getCollection();

<!-- Get all documents -->
const allUsers = await collection.find({}).toArray();
console.log('All users:', allUsers);

<!-- Find users older than 30 -->
const olderUsers = await collection
  .find({ age: { $gt: 30 } })
  .toArray();

<!-- Find users with specific name -->
const bob = await collection.findOne({ name: 'Bob' });

<!-- Find user with name 'Alice' and update age -->
const result = await collection.updateOne(
  { name: 'Alice Johnson' },
  { $set: { age: 29 } }
);

console.log('Modified count:', result.modifiedCount);

<!-- Add a new field to all users -->
const result = await collection.updateMany(
  {}, <!-- empty filter matches all -->
  { $set: { active: true } }
);
console.log('Modified count:', result.modifiedCount);

const result = await collection.deleteOne({ name: 'Charlie' });
console.log('Deleted count:', result.deletedCount);

<!-- Delete all users younger than 25 -->
const result = await collection.deleteMany({ age: { $lt: 25 } });
console.log('Deleted count:', result.deletedCount);

const http = require('http');

const server = http.createServer(async (req, res) => {
  const collection = await getCollection();
  
  if (req.url === '/api/users' && req.method === 'GET') {
    const users = await collection.find({}).toArray();
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify(users));
  }
  
  <!-- Handle POST request to create user -->
  if (req.url === '/api/users' && req.method === 'POST') {
    let body = '';
    req.on('data', chunk => body += chunk);
    req.on('end', async () => {
      const newUser = JSON.parse(body);
      const result = await collection.insertOne(newUser);
      res.writeHead(201);
      res.end(JSON.stringify({ id: result.insertedId }));
    });
  }
});