How to update using compound field name in MongoDB via NodeJS?

Question

JavaScript

there is a table like this:

{
  "_id" : ObjectId("5379b1b81cdcaf4db70cc16f"),
  "hash" : "123",
  "serverList" : {
    "server1" : {
      "host": "http://192.168.5.138:80/",
                        "url" : "/123/",
      "ssid" : "321"
    },
    "server2" : {
      "host": "http://192.168.5.144:80/",
                        "url" : "/123/",
      "ssid" : "321"
    }
  }
}

It is sometimes necessary to update the ssid and url fields. I'm trying to do this:

var data = JSON.parse(params).result, ssid = 'serverList.'+server[i]+'.ssid', url = 'serverList.'+server[i]+'.url';
leaders.update({'hash':request.cookies.hash}, {'$set':{ ssid: data['ssid'], url: data['sessionurl']}}, function(e, d) {
  console.dir(e);
  console.dir(d);
});
// Где server[i] это 'server1' или 'server2', а в data приходят нужные url и ssid

But, as far as I understand, the string that is contained in ssid and url is not transmitted, but stupidly ssid and url are transmitted as a field value. How to correctly compose the query string so that update takes place on the desired (dynamically generated) path?

Answer 1

So far I decided to form a change request as an object ...

var $set = {};
$set['$set'] = {};
$set['$set']['serverList.'+i+'.ssid'] = data['ssid'];
$set['$set']['serverList.'+i+'.url'] = data['sessionurl'];

And pass this object in the request body. Are there more beautiful and elegant solutions?