Node.js MySQL Create Database Connection

MySQL is widely used database management system used in web application. It is popular and easy to connect with any web application.

In this article, we will learn how to connect MySQL data base with Node.js app.

Note: It is assumed that you have already installed MySQL server and Node.js. If you need to install into Linux system, you can download and install from MySQL and Node.js official website.

After successfully installed Node.js and MySQL, we need to install mysql driver for Node.js to interact with database. We will use npm package manager to install node.js packages.

You might want to create package.json file to save all dependencies installed in the package. You can run following command and input the few questions asked about application.

npm init -y

Now install mysql package using below command.

npm install mysql

This will create node_modules directory with all node package installed in it. package.json file saves all dependencies installed in the application.

Now create server.js file, in which we will connect mysql database with Node.js. In the server.js file first import mysql module using require() method.

const mysql = require('mysql');

Now, create mysql.createConnection() method and pass MySQL credentials object into it. 

const conn = mysql.createConnection({
    host: 'localhost',
    port: 3306,
    database: 'mydbname',
    user: 'root',
    password: 'secret'
});

Now, we will connect database using connect() method.

conn.connect((err) => {
    if (err) {
        // throw err;
        console.log(err.message);
    } else {
        // connection established
        console.log('Connected with mysql database.');
    }
});

You may close the connection programmatically using end() method.

conn.end(function(err) {
    if (err) {
        // throw err;
        console.log(err.message);
    } else {
          console.log('Connection with mysql closed.');
    }
});

Or close the connection forcefully using destroy() method.

conn.destroy();

So far in this article, we have connected MySQL database with Node.js. In the later articles, we will query to MySQL database from Node.js.