Select nested fields in mongo db

Question

I have a collection in mongodb where fields are nested under a language root:

{
    en: {
        title: \"eng title\",
        content: \"eng content\",
            


        

Answer 1

You need to aggregate as below:

• Construct a find object to match only the records containing($exists) the language.
• Construct a Projection object to project the fields.

Code:

var currentLang = "en";
var project = {};
project["title"] = "$"+currentLang+".title";
project["content"] = "$"+currentLang+".content";
project["images"] = 1;

var find = {};
find[currentLang] = {"$exists":true};

db.collection.aggregate([
{$match:find},
{$project:project}
])