Express - MySQL conn.end() is not functioning (Cannot enqueue after invoking quit)

Question

I have already read the post Node Mysql Cannot Enqueue a query after calling quit, the conn.end() is in my query block.

My issue is that conn.end in my dashboard.js does not work and breaks the app with the following error.

I need to use it because MySQL connections are flooding the system till Database stop accepting more of them since they all stay open each time that are used.

For this post I will use only one (dashboard.js) of the several routes of my NodeJS application.

`Event.js` is not a part of my working files, probably is a file from `./node_modules`

|events.js:183 
      throw er; // Unhandled 'error' event
      ^

Error: Cannot enqueue Quit after invoking quit.
    at Protocol._validateEnqueue (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\Protocol.js:204:16)
    at Protocol._enqueue (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\Protocol.js:139:13)
    at Protocol.quit (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\Protocol.js:92:23)
    at Connection.end (E:\NodeJS\Project-Change\node_modules\mysql\lib\Connection.js:249:18)
    at ServerResponse.res.end (E:\NodeJS\Project-Change\node_modules\express-myconnection\lib\express-myconnection.js:114:54)
    at ServerResponse.send (E:\NodeJS\Project-Change\node_modules\express\lib\response.js:191:8)
    at fn (E:\NodeJS\Project-Change\node_modules\express\lib\response.js:896:10)
    at View.exports.renderFile [as engine] (E:\NodeJS\Project-Change\node_modules\ejs\lib\ejs.js:323:3)
    at View.render (E:\NodeJS\Project-Change\node_modules\express\lib\view.js:76:8)
    at Function.app.render (E:\NodeJS\Project-Change\node_modules\express\lib\application.js:527:10)
    at ServerResponse.res.render (E:\NodeJS\Project-Change\node_modules\express\lib\response.js:900:7)
    at Query._callback (E:\NodeJS\Project-Change\routes\dashboard.js:39:17)
    at Query.Sequence.end (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\sequences\Sequence.js:88:24)
    at Query._handleFinalResultPacket (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\sequences\Query.js:139:8)
    at Query.EofPacket (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\sequences\Query.js:123:8)
    at Protocol._parsePacket (E:\NodeJS\Project-Change\node_modules\mysql\lib\protocol\Protocol.js:279:23)

app.js (only relative lines)

var express  = require('express'),
    path     = require('path'),
    bodyParser = require('body-parser'),
    app = express(),
    expressValidator = require('express-validator'),
    session = require('express-session'),
    passport = require('passport'),
    flash = require('connect-flash'),
    passportConfig = require('./config/passport'),
    dbConfig = require('./config/db');

// skipping code about static files, bodyparser, expressValidator, session, passport

passportConfig(passport)

/*MySQL connection*/
var connection  = require('express-myconnection'),
    mysql = require('mysql');

app.use(
    connection(mysql, dbConfig,'request')
);

var dashboard = require('./routes/dashboard.js'); // in this route I apply conn.end()
var router = require('./routes/rates.js');

// skipping app.post/app.get code for /login & /logout & isLoggedIn middleware

app.use('/', router);
app.use('/', dashboard); // issue on that

app.get('/',function(req,res){
    res.render('./dashboard.ejs'); //issue on that
});

module.exports = app;

routes/dashboard.js (route)

var express = require('express');
var router = express.Router();

var dashboard = express.Router();

dashboard.use(function(req, res, next) {
    console.log(req.method, req.url);
    next();
});

var dashboard = router.route('/');


//show the CRUD interface | GET
dashboard.get(function(req,res,next){

    req.getConnection(function(err,conn){

        if (err) return next("Cannot Connect");

        var query = conn.query('SELECT SUM(total_price) AS transactions_total FROM transactions WHERE date_created = CURDATE(); SELECT SUM(total_profit) AS total_profit FROM transactions',  function(err,rows){


            if(err){
                console.log(err);
                return next("MySQL error, check your query");
            }

            var ab = {data:rows[0]};
            var total_profit = {data:rows[1]};

            res.render('dashboard',{ab, total_profit});

            conn.end(); // causes the described error

         });

            // conn.end(); even tried here

    });

});

dashboard.all(function(req,res,next){
    console.log("route for dashboard executed");
    console.log(req.params);
    next();
});


module.exports = router;
console.log('dashboard.js loaded!');

config/db.js

module.exports = {
          host     : 'localhost',
          user     : 'root',
          password : '',
          database : 'mydb',
          multipleStatements: true, 
          debug    : false
}

config/passport.js

External presentation in case is needed here