Database is not connecting!

Question

My database isn’t connecting. When doing a refctoring of my code following the MVC standard the database stopped working.

Follow link with the test files: https://github.com/LeonardoVini/node-refctoring

app js.

const app = require('./config/server')

// port must be set to 9095 because incoming http requests are routed from port 80 to port 9095
app.listen(9095, function () {
    console.log('Node app is running on port 9095');
});

server.js

const express = require('express');
const consign = require('consign')
const bodyParser = require('body-parser');
const cors = require('cors');

const corsOptions = {
    origin: 'http://localhost:4200',
    optionsSuccessStatus: 200
}

const app = express();

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.use(cors(corsOptions))

consign()
    .include('app/routes')
    .then('config/dbConnection.js')
    .then('app/models')
    .then('app/controllers')
    .into(app);

module.exports = app;

dbConnection.js

const mysql = require('mysql')

const connMySQL = () => {
    return mysql.createConnection({
        host: 'localhost',
        user: 'root',
        password: 'eqix1998',
        database: 'quotedb',
        port: 3306
    });
}

module.exports = () => {
    return connMySQL;
}

Routes > Quotes.js

module.exports = (application) => {
    application.get('/quotes', (req, res) => {
        application.app.controllers.quotes.quotes(application, req, res);
    });
}

Controllers > Quotes.js

module.exports.quotes = (application, req, res) => {
    var connection = application.config.dbConnection();
    var quotesDAO = new application.app.models.QuotesDAO(connection);

    quotesDAO.getQuotes((error, results) => {
        res.send(results)
    });
}

Models > Quotes.js

function QuotesDAO(connection){
    this._connection = connection;
    console.log(this._connection)
}

QuotesDAO.prototype.getQuotes = (callback) => {
    this._connection.query('SELECT * FROM quotes', callback)
}

module.exports = () => {
    return QuotesDAO;
}

File tree:

That is the mistake:

Answer 1

I checked your code and made the changes that worked for me.

Follow them:

• First, there in the prototype, do not use Arrow-Function, for the this will not reference the object QuotesDAO, but yes to any global object.

  Would look like this:

   QuotesDAO.prototype.getQuotes = function(callback){
     this._connection.query('sua query', callback);
   }
  

• Second, if it doesn’t work, in your database connection file, dbConnection.js, do the following:

  const connMySQL = mysql.createConnection({
   host: 'localhost',
   user: 'root',
   password: 'eqix1998',
   database: 'quotedb',
   port: 3306
  });
  connMySQL.connect(function(erro){
   if(erro)
    return console.log(erro);
    console.log('Conectou!');
  });
  
  module.exports = () => connMySQL
  

  The method connect will try to make the connection to the bank and inform if there was success. In the method you wrote, if you put a console log. the message will appear disconnect:

  console.log(connMySQL().state); // disconnect