Q1. How do you connect Node.js to MySQL?
Use the mysql2 package. Install: npm install mysql2. Create connection pool:
const mysql = require('mysql2'); const pool = mysql.createPool({ host: 'localhost', user: 'root', password: 'password', database: 'mydb', waitForConnections: true, connectionLimit: 10 });Q2. What's the difference between mysql and mysql2 packages?
mysql2 is a fork of mysql with better performance, promise support, prepared statements, and more features. It's the recommended choice for new projects. mysql2 supports both callbacks and promises (via .promise()), while the original mysql package requires callbacks or manual promisification.
Q3. How do you execute queries with mysql2?
With promises:
const [rows, fields] = await pool.promise().query('SELECT * FROM users WHERE id = ?', [userId]);Q4. How do you handle connection errors with MySQL?
Use try/catch around queries. For connection errors, the pool will handle reconnection automatically. Listen for error events:
pool.on('error', (err) => { console.error('Pool error', err); });pool.getConnection((err, connection) => { if (err) throw err; });Q5. How do you use ORMs like Sequelize with MySQL?
Sequelize is a popular ORM for SQL databases. Install: npm install sequelize mysql2. Define models:
const User = sequelize.define('User', { name: DataTypes.STRING, email: DataTypes.STRING });