const
    express      = require('express'),  //include express module
    Url          = require('url'),    //include url module
    bodyParser   = require('body-parser'),  //for post requests
    mysql        = require('mysql'),  //include mySQL module
    cookieParser = require('cookie-parser'),
    session      = require('express-session'),
    app          = express();   //server

var jsonParser = bodyParser.json();
app.use(jsonParser);

var connection = mysql.createConnection({  //connecting to database
    host: '127.0.0.1',  //ip adress
    user: 'admin',  //name of user in mySQL
    password: '123',  //user password
    database: 'news'  //database name
});

connection.connect(function(err) {  //establishing connecting to DB
    if (err) throw err;   //if we have some exception
    console.log('Connected!');  //if everything is OK
});

app.set('view engine', 'ejs');  //connect ejs to application
app.use('/public', express.static('public'));  //using static folder for css and more
app.use(bodyParser.urlencoded({ extended: true })); //using body parser for POST requests

var user = {
    username: 'moderator',
    password: '123'
}

var sessionHandler = require('./js/sessionHandler');
var store          = sessionHandler.createStore();

app.use(cookieParser());
app.use(session({
    store: store,
    resave: false,
    saveUninitialized: true,
    secret: 'supersecret'
}));

//generate root page for user
app.get('/', function(request,response) {
    connection.query('SELECT title, text, date FROM news', function(err, result) {
        if (err) throw err;
        response.render('user', { posts: result });
        response.end();
    });
});

//genetate moderator page
app.get('/moderator', function(request,response) {
    if (request.session.username == 'moderator') {
        connection.query('SELECT title, text, date FROM news', function(err, result) {
            if (err) throw err;
            response.render('moderator', { posts: result });
            response.end();
        });
    } else {
        response.status(403).send('Access Denied!');
    }
});

app.get('/log-in', function(request, response) {
    response.render('log-in');
});

app.get('/log-out', function(request, response) {
    console.log('logging out!' + request.session.username);
    request.session.username = '';
    console.log('logged out!' + request.session.username);
    response.redirect('/log-in');
    response.end();
});


app.post('/log-in', function(request, response) {
    console.log('Request body username: ' + request.body.username);
    console.log('Request body password: ' + request.body.password);
    console.log('User Username: ' + user.username);
    console.log('User Password: ' + user.password);
    var foundUser;
    if (user.username == request.body.username && user.password == request.body.password)
        foundUser = user.username;
    console.log('Found User: ' + foundUser);
    if (foundUser !== undefined) {
        request.session.username = request.body.username;
        response.redirect('/moderator');
        console.log('Session Username: ' + request.session.username);
        console.log('____________________________');
    } else {
        response.status(401).send('Login Error!');
    }
});

//add new post to DB
app.post('/moderator', function(request, response) {
    if (!request.body) return sendStatus(400);

    var                         //date of adding new post
        date     = new Date(),
        postDate = date.getDate() + '/' + date.getMonth() + '/' + date.getFullYear();

    //push into DB
    connection.query('INSERT INTO news(`title`, `text`, `date`) VALUES(' + ''' + request.body.title + ''' + ',' + ''' + request.body.text + ''' + ',' + ''' + postDate + ''' + ')', function(err, result) {
        if (err) throw err;
    });

    response.redirect('/moderator');
    response.end();
});

app.listen(8080);  //listening to the port

const
    cookieParser = require('cookie-parser'),
    session      = require('express-session'),
    MSSQLStore   = require('express-mysql-session')(session),
    mssql        = require('mssql');

module.exports = {
    createStore: function() {
        var config = {
            user: 'admin',
            password: '123',
            server: '127.0.0.1',
            database: 'news',
            port: 3306,
            pool: {
                max: 10,
                min: 0,
                idleTimeoutMillis: 30000
            }
        }
        return new MSSQLStore(config);
    }
}

<script>
        window.onload = function() {
            var
                logIn     = document.getElementById('log_in'),
                userLogin = document.getElementById('login'),
                userPass  = document.getElementById('password');

            logIn.onclick = function() {
                var xhr = new XMLHttpRequest();
                xhr.open('POST', '/log-in');

                var userData = {
                    username: userLogin.value,
                    password: userPass.value
                };

                xhr.setRequestHeader('Content-Type', 'application/json');
                xhr.send(JSON.stringify(userData));
            };
        }
    </script>

<script>
        window.onload = function() {
            var logOut    = document.getElementById('log_out');

            logOut.onclick = function() {
                var xhr = new XMLHttpRequest();
                xhr.open('GET', '/log-out');
                xhr.send();
            };
        }
    </script>

Connected!
Request body username: moderator
Request body password: 123
User Username: moderator
User Password: 123
Found User: moderator
Session Username: moderator
____________________________
Request body username: undefined
Request body password: 123
User Username: moderator
User Password: 123
Found User: undefined
logging out!moderator
logged out!