//assuming i have database:
Person_table(ID int A_I, NAME varchar, AGE int)
//code:
var p = new Person("John", 22);
p.writeToDatabase();
//the object is now written in database

var mysql = require('mysql');
var conn = mysql.createPool({
    host : 'localhost',
    database: 'db_name',
    user: 'user_name',
    password : 'pass',
    multipleStatement: true,
    connectionLimit : 10
});

conn.getConnection(function(err){
    if(err) throw err;
});

module.exports = conn;

var db = require('./db.js');

function Person(n, a) {
    this.name = n;
    this.age = a;
}

Person.prototype.writeToDatabase = function (callback) {
    db.query("INSERT INTO Person_table(NAME, AGE) VALUES(?,?)", [this.name, this.age], function (err, rows) {
        if (err) return callback(err);
        else return callback(null, rows);
    });
}

module.exports = Person;

var Person = require('./person.js')

var p = new Person("John", 22);

p.writeToDatabase(function(err, rows){
    if(err) console.log(err);
    else console.log("written to DB");
});