MongoDb : How to insert additional object into object collection?

I have a document "owner" that can have "n" number of camps and camps have "instructors" and instructors have "classes". Earlier I tried accomplishing this with nested arrays (see link to my post below), however I learned that the positional operator "$" does not nest that deep. MongoDB: Adding an array into an existing array

However, I learned that the workaround would be to use object collections instead of arrays. I'm assuming that I have to use "update" with "$set" to add additional "camps", however every time I do all it does is overwrite(update) the previous camp that was inserted.

Below is the hierarchical structure I am trying to accomplish:

owner = {

    firstName: 'john',
    lastName: 'smith',
    ownerEmail: 'john.smith@gmail.com',

    camps : {

        {
            name: 'cubs-killeen',
            location: 'killeen'
        },

        {
            name: 'cubs-temple',
            location: 'temple'
        },

        instructors : {

            {
                firstName: 'joe',
                lastName : 'black'
            },

            {
                firstName: 'will',
                lastName : 'smith'
            }        
        }

    }

}

I have also been trying the following:

db.owners.update({ownerEmail:'john.smith@gmail.com'}, {$set: { camps:{ {name:'cubs-killeen'} } }})

but this throws an unexpected identifier { error.

Any help with some sample mongo commands to achieve the structure above would be most appreciated.

V/R

Chris

As other mentioned, The structure you want is not valid. I recommend the following structure for your owner document:

    {
    "_id" : ObjectId("51c9cf2b206dfb73d666ae07"),
    "firstName" : "john",
    "lastName" : "smith",
    "ownerEmail" : "john.smith@gmail.com",
    "camps" : [
            {
                    "name" : "cubs-killeen",
                    "location" : "killeen"
            },
            {
                    "name" : "cubs-temple",
                    "location" : "temple"
            }
    ],
    "instructors" : [
            {
                    "firstName" : "joe",
                    "lastName" : "black"
            },
            {
                    "firstName" : "will",
                    "lastName" : "smith"
            }
    ]
}

and then

db.stack.update(
  { ownerEmail: "john.smith@gmail.com" },
  {
    $push: {
      camps: { name: "cubs-killeen", location: "some other Place" }
    }
  }
);

Having this, you can add camps like this:

Hope it helps.