Express MySQL Integration Guide

In Express, you can utilize the MySQL module to connect with and manipulate MySQL databases. Here’s a simple example demonstrating how to use MySQL in Express:

1. Firstly, the MySQL module needs to be installed.

npm install mysql

1. Introducing the mysql module in an Express application and establishing a database connection.

const mysql = require('mysql');

const connection = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: 'password',
  database: 'my_database'
});

connection.connect((err) => {
  if (err) {
    console.error('Error connecting to MySQL: ' + err.stack);
    return;
  }
  console.log('Connected to MySQL as id ' + connection.threadId);
});

1. You can execute SQL queries to operate on databases.

app.get('/users', (req, res) => {
  connection.query('SELECT * FROM users', (err, results) => {
    if (err) {
      console.error('Error querying MySQL: ' + err.stack);
      return;
    }
    res.json(results);
  });
});

app.post('/users', (req, res) => {
  const { username, email } = req.body;
  connection.query('INSERT INTO users (username, email) VALUES (?, ?)', [username, email], (err, result) => {
    if (err) {
      console.error('Error inserting into MySQL: ' + err.stack);
      return;
    }
    res.send('User added successfully');
  });
});

In the code example above, we establish a database connection and perform queries and inserts using the connection.query method. In actual applications, various types of SQL operations can be executed as needed to interact with the MySQL database.