Access to session object in routes nodeJs

I'm trying to pass the object session from App.js to other routes files in node.js using express-session,the object is defined in app.js and undefined in the other routes,Is there a solution?

app.post('/connect',function(req,res){
    sess=req.session;
    sess.user=req.body.user;
    sess.password=req.body.password;
    sess.server=req.body.server;
    sess.database=req.body.database;
    console.log(sess)
    user = req.body.user;
    password = req.body.password;
    server = req.body.server;
    database = req.body.database;

    var config = {
        user: user,
        password: password,
        server: server,
        database: database
    };



    // connect to your database
    sql.connect(config, function (err) {

        if (err)  {res.json({success: false, message: "error connexion to SQL Server"});
            sql.close()}
        else{

            res.json({success: true, message: "connexion established to SQL Server"});

            sql.close();
        }
    });
});

via Laamiri Oussema