اتصال به دیتابیس MySQL در برنامه‌های NodeJS

npm install mysql

DB_HOST=olympus.liara.cloud
DB_PORT=34008
DB_NAME=festive_villani
DB_USER=root
DB_PASS=d0NRg5Rh7TzbAzJVl7SyeMAB

const express = require('express');
const mysql = require('mysql');

const app = express();

const dbConfig = {
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  database: process.env.DB_NAME,
  user: process.env.DB_USER,
  password: process.env.DB_PASS
};
const connection = mysql.createConnection(dbConfig);

connection.connect((err) => {
  if (err) {
    console.error('error in connecting to db:', err);
    app.locals.dbConnected = false;
    return;
  }

  console.log('connected to db successfully');
  app.locals.dbConnected = true;
});

app.get('/', (req, res) => {
  res.send(app.locals.dbConnected ? 'connected to db successfully' : 'error in connecting to db!');
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`server is listening on port ${PORT}`);
});

process.on('SIGINT', () => {
  connection.end();
  console.log('db disconnected.');
  process.exit();
});

npm install mysql2

const mysql = require('mysql2/promise');

const dbConfig = {
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  database: process.env.DB_NAME,
  user: process.env.DB_USER,
  password: process.env.DB_PASS,
  waitForConnections: true,
  connectionLimit: 10,
  queueLimit: 0,
};
const pool = mysql.createPool(dbConfig);


(async () => {
  try {
    const connection = await pool.getConnection();
    console.log('Connected to the MySQL server.');
    connection.release();
  } catch (error) {
    console.error('Error connecting to the MySQL server:', error);
  }
})();