Mongo DB query of complex json structure - json

Question

Say I have a json structure like so:
{
"A":{
"name":"dog",
"foo":"bar",
"array":[
{"name":"one"},
{"name":"two"}
]
},
"B":{
"name":"cat",
"foo":"bar",
"array":[
{"name":"one"},
{"name":"three"}
]
}
}
I want to be able to do two things.
1: Query for any "name":* within "A.array".
2: Query for any "name":"one" within "*.array".
That is, any object within a specific document's array, and any specific object within any document's array.
I hope I have used proper terminology here, I am just starting to familiarize myself with a lot of these concepts. I have tried searching for an answer but am having trouble finding something like my case.
Thanks.
EDIT:
Since I still haven't really made progress towards this, I'll just explain what I'm trying to do: I want to use the "AllSets" dataset (after I trim it down below 16mb) available on mtgjson.com. I am having problems getting mongo to play nicely though.
In an effort to try and learn what's going on, I have downloaded one set: http://mtgjson.com/json/OGW.json.
Here is a photo of its structure laid out:
I am unable to even get mongo to return an object from within the cards array using:
"find({cards: {$elemMatch: {name:"Deceiver of Form"}}})"
"find({"cards.name":"Deceiver of Form"})"
When I run either of the commands above it just returns the entire document to me.

Answer 1

You could use the positional projection $ operator to limit the contents of an array. For example, if you have a single document like below:
{
"block": "Battle for Zendikar",
"booster": "...",
"translations": "...",
"cards": [
{
"name": "Deceiver of Form",
"power": "8"
},
{
"name": "Eldrazi Mimic",
"power": "2"
},
{
"name": "Kozilek, the Great Distortion",
"power": "12"
}
]
}
You can query for a card name matching "Deceiver of Form", and limit fields to return only the matching array card element(s) using:
> db.collection.find({"cards.name":"Deceiver of Form"}, {"cards.$":1})
{
"_id": ObjectId("..."),
"cards": [
{
"name": "Deceiver of Form",
"power": "8"
}
]
}
Having said the above, I think you should re-consider your data model. MongoDB is a document-oriented database. A record in MongoDB is a document, so having a single record in a database does not bring out the potential of the database i.e. similar to storing all data in a single row in a table.
You should try storing the 'cards' into a collection instead. Where each document is a single card, (depending on your use case) you could add a reference to another collection containing the deck information. i.e: block, type, releaseDate, etc. For example:
// a document in cards collection:
{
"name": "Deceiver of Form",
"power": "8",
"deck_id": 1
}
// a document in decks collection:
{
"deck_id": 1,
"releaseDate": "2016-01-22",
"type": "expansion"
}
For different types of data model designs and examples, please see Data Model Design.