Создание простой регистрации / входа в систему с использованием node.js и mysql

function confirm(username, email, password, callback) {
    var post = { username: username, email: email, password: password };
    var params = [post.username, post.email];
    var queryTest = global.connect.con.query('SELECT username, email FROM Utilizador WHERE username = ? AND email = ?', params, function(err, rows, fields) {
        console.info(rows);
        if (!err) {
            if (rows != "") {
                console.info("user already exists");
            }
            else {
                var query = global.connect.con.query('INSERT INTO Utilizador SET ?', post, function(err, rows, fields) {
                    console.info(query.sql);
                    if (!err) {
                        console.info("Number of records inserted: " + rows.affectedRows);
                    }
                    else
                        console.info('Error while performing Query.', err);
                });
            }
        }
    });
}