Updating Array inside an array using mongodb

Question

I'm having great difficulties with something that is probably most basic. I have the following entry in my database

{"_id"=>BSON::ObjectId('4ec2429c85aab65f16fa2700'),
     "owner"=>4,
     "friends"=>{"mappings"=>{"Test"=>34}},
     "friendid"=>"309"}

I'm trying to insert another value into the mappings array. Something like "Testing"=>10

Unfortunately I'm having no luck what so ever when trying a variety of different approaches. Currently I'm trying the below with no success.

BasicDBObject updateQuery = new BasicDBObject();
updateQuery.put("owner", owner);
updateQuery.put("friendid", userid);
BasicDBObject updateCommand = new BasicDBObject();
updateCommand.put("$push",  new BasicDBObject("friends.mappings", 
                                    new BasicDBObject(clustername, clusterid)));
WriteResult result = collection.update(updateQuery, updateCommand,false,true);

I'd appreciate it if someone could tell me what I'm doing wrong. I'm assuming its something really obvious!

P.s I'm using the latest Driver and latest MongoDB

Answer 1

Check if your database is 'capped' (that is, created with capped: "true")