Node.js: Why not saved session? - node.js

Question

Here's the code:
app.get('/vklogin', function(request, response) {
console.log('Авторизация через соц.сеть "Вконтакте"'.green);
var url_parts = url.parse(request.url, true);
var query = url_parts.query;
var data = querystring.stringify({
client_id: '4836170',
client_secret: 'cPkR53zhon0lU7TAiz9f',
code: query.code,
redirect_uri: 'http://' + request.headers.host + '/vklogin'
});
var options = {
host: 'oauth.vk.com',
port: 443,
path: '/access_token?' + data,
method: 'GET'
};
var httpsreq = https.request(options, function(response) {
response.setEncoding('utf8');
response.on('data', function(chunk) {
var chunk = JSON.parse(chunk);
pg.connect(dbconfig, function(err, client, done) {
if (err) {
return console.error('Ошибка подключения к БД',err);
}
client.query('select * from users where vk = $1', [chunk.user_id], function(err, result) {
done();
if (err) {
console.error('Ошибка получения данных',err);
} else {
if (result.rows[0]) {
console.log(result.rows[0]);
request.session.authorized = true;
request.session.userid = result.rows[0].id;
} else {
console.log('Попытка создания нового пользователя. ');
client.query("insert into users (email, vk) values ('" + chunk.email + "', " + chunk.user_id + ") returning id", function(err, result) {
done();
if (err) {
console.error('Ошибка записи данных в БД', err);
} else {
request.session.authorized = true;
request.session.userid = result.rows[0].id;
console.log('Добавлен новый пользователь # ' + result.rows[0].id);
}
});
}
}
client.end();
});
console.log("№ пользователья: " + request.session.userid);
});
});
});
httpsreq.end();
if (request.session.authorized) {
response.writeHead(301, {
Location: 'http://' + request.headers.host + '/cabinet'
});
} else {
response.writeHead(301, {
Location: 'http://' + request.headers.host
});
}
response.end();
});
That is why outside functions session is not saved? What is wrong in my code?
Inside the function, everything is fine, outside functions - undefined.
After this session, the logic must be maintained and be available everywhere, too, everywhere, or is not it?
Tried to declare a variable with the session, but it also did not work, and no error does not give, do not even know where to dig.
var sess;
app.get('/vklogin', function(request, response) {
sess = request.session;
// other code...
});
UPD:
My problem is related to the lack of understanding of the control of asynchronous processes. I can not understand how to perform the originally one - database queries, information preservation in the session, and then check the session variables and forwarding to the desired page.
If you know how to make the correct execution order for me, write the answer.

Answer 1

Ok, I find need async pattern. Look here: http://book.mixu.net/node/ch7.html