CODEWITHSUNDEEP
arraysnode.jsmongodb
Thanhtu150
Thanhtu150

Reputation: 91

Get specific data in mongodb nodejs

i'm working with nodejs server using mongoDB. Now i have a sample data:

 {
        "_id": ObjectId("555f1c0c7f4b820758b439b0"),
        "user": "Guest1",
        "friend": [{
            "myfriend": "Guest2",
            "info": []
        }, {
            "myfriend": "Guest3",
            "info": []
        }]
    }

Now i want to put all "myfriend" into array, like this:

var listfriend = ["Guest2","Guest3"];

So how can i do it ?

Thank for read :)

Upvotes: 1

Views: 123

Answers (2)

chridam
chridam

Reputation: 103305

Try using the map() method as follows:

var listfriend = db.names.findOne(
    {"user" : "Guest1"}, 
    {"_id": 0, "friend": 1}
).friend.map(function(obj){ 
    return obj.myfriend; 
});

console.log(listfriend); // ["Guest2","Guest3"]

Upvotes: 2

Kay
Kay

Reputation: 3012

Did you want to use the aggregation framework?

var aggregateFriends = function( db, callback) 
{
  db.collection('test').aggregate( 
    [ 
      { $unwind: "$friend" },
      { $group: { _id: "$user", friends: {$push: "$friend.myfriend" } } }
    ]
  ).toArray( function( err, result ) { 
      console.log(result); 
      db.close(); 
  } ); 
};


var MongoClient = require('mongodb').MongoClient;
var assert = require('assert')
var ObjectId = require('mongodb').ObjectID;
var url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function(err, db) {
    assert.equal(null, err);
    aggregateFriends( db, function() { db.close(); });
} );

Upvotes: 0

Related Questions