Got connect ECONNREFUSED node

I develop with mates for school a nodejs website. But I have this problem when I npm start. I have been looking for few times a solution but find anything working for us.

Here is the error we get:

read: [Function],
  secret: undefined,
  cookies: { 'jenkins-timestamper-offset': '-7200000' },
  signedCookies: {},
  route:
   { path: '/question',
     stack: [ [Object], [Object], [Object] ],
     methods: { post: true, put: true, delete: true } } }
connect ECONNREFUSED

I just pick the last few lines because there are too many to copy/paste.

Here is my index.js file:

var express = require('express');
var mysql   = require("mysql");
var md5 = require('MD5');
var router = express.Router();
var app=express();
var bodyParser = require("body-parser");
var questionList = [];

app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());


router.get("/ListQuestion",function (req,res){

    client.query('SELECT * from question',function (err,results) {
        res.render('ListQuestion', {listeQuestion: results});
    })
});
/* GET home page. */
router.get('/', function(req, res) {
  res.status(200).render('index', { title: 'Web-Service' });
});


router.get('/answer/:URI', function(req, res) {

    var client=mysql.createConnection({
        host     : '172.17.0.2',
        user     : 'root',
        password : 'rootroot',
        database : 'questionreponse'
    });
    client.query('SELECT * from question WHERE answer !="NULL" AND uri= "'+req.params.URI+'" GROUP BY answer ORDER BY answer DESC' , function (error, results) {
        console.log(results);
        if (results && results[0] && results[0].answer && results[0].answer!=''){
            res.status(200).render('answer', {answer: results[0].answer});
            console.log(results[0].answer);
        }else{

Same as before I cant copy the whole file because too long, if you need specific lines you can ask for.

If you have any solution to make it work I will take it.

Thanks in advance. :)

via Raydowne