MongoDB with Java - find a document and nested insert update

Question

I have a Document like this:

{
    timestamp_hour: ISODate("xxx"),
    userid: "xxx",
    type: "xxx",
    balances: {
        1: {input: 100, output: 200},
        2: {input: 200, output: 300},
        500: {input: 5000, output: 5500},
        ...
    }
}

I want to insert new pair of number: {input: xxx, output: yyy} into balances, if the timestamp_hour and userid both match. (It is more like an upsert, I am told)

How the code would be? I am with Java 8 and org.apache.storm.core 1.1.

Answer 1

No upsert here. Just adding a new embedded field inside balances when the document is found.

MongoClient mc = new MongoClient();
MongoDatabase db = mc.getDatabase("db");
MongoCollection col = db.getCollection("col");

Bson query = Filters.and(Filters.eq("timestamp_hour", timestampHour), Filters.eq("userid", userId));
Document uDoc = new Document();
uDoc.put("input", xxx);
uDoc.put("output", yyy);

Bson update = Updates.set("balances." + number, uDoc);

col.updateOne(query, update);