การเชื่อมต่อฐานข้อมูลใน Express.js: การเชื่อมต่อกับ MongoDB และ MySQL

npm install mongodb

const MongoClient = require('mongodb').MongoClient;  
const url = 'mongodb://localhost:27017/mydb';  
  
MongoClient.connect(url,(err, client) => {  
  if(err) throw err;  
  const db = client.db('mydb');  
  // Perform database operations  
  client.close();  
});  

npm install mysql

const mysql = require('mysql');  
const connection = mysql.createConnection({  
  host: 'localhost',  
  user: 'root',  
  password: 'password',  
  database: 'mydb'  
});  
  
connection.connect((err) => {  
  if(err) throw err;  
  // Perform database operations  
  connection.end();  
});  

// MongoDB  
db.collection('users').insertOne({ name: 'John', age: 30 });  
  
// MySQL  
const sql = 'INSERT INTO users(name, age) VALUES(?, ?)';  
connection.query(sql, ['John', 30],(err, result) => {  
  if(err) throw err;  
  console.log('Record inserted: ' + result.affectedRows);  
});  

// MongoDB  
db.collection('users').find({}).toArray((err, result) => {  
  if(err) throw err;  
  console.log(result);  
});  
  
// MySQL  
const sql = 'SELECT * FROM users';  
connection.query(sql,(err, result) => {  
  if(err) throw err;  
  console.log(result);  
});