MySQL connector or singleton for express node app

app.js

// getting connection from mysql.js file 
// creating new mysql connection and checking it 
const mysqlConnection = require('./model/mysql');
const mysql = require('mysql');
app.get('/testmysql', function(req, res) {
    console.log(mysqlConnection.name);
    mysqlConnection.createConnection().then((connection) => {
        let query = "select * from zeus_user";
        let table = [];
        query = mysql.format(query, table);
        connection.query(query, (err, result) => {
            if (err) {
                res.send("error");
                console.log(err.stack);
            } else {
                // release the connection after its use.
                connection.release();
                res.json({ "STATUS": true, "RESULT": result });
            }
        })
    }).catch((error) => {
        res.send("error");
        console.log(error.stack);
    });
})

mysql.js

// this is for creating mysql connection 
// this will act as your singleton class if your coming from java
// for more information please visit https://www.npmjs.com/package/mysql
var mysql = require('mysql');
const Q = require('q');
var pool = mysql.createPool({
    connectionLimit: 10,
    host: 'localhost',
    user: 'root',
    password: '',
    database: 'database_name'
});

var mysqlConnection = {};
mysqlConnection.createConnection = createConnection;
mysqlConnection.name = "saiumesh";
module.exports = mysqlConnection;

function createConnection() {
    let deferred = Q.defer();
    pool.getConnection((err, connection) => {
        if (err) {
            deferred.reject(err);
        } else {
            deferred.resolve(connection);
        }
    })
    return deferred.promise;
}