Working with hierarchical data in Mongo.

Answer 1

So I've been struggling with this all day, and sure enough, the moment I post it to StackOverflow I run across something that gives me the answer. The proper answer looks like this:

db.builds.update({
  name: "build from changeset #5678",
  "assemblies.name": "someAssembly1.dll"
},{
 $addToSet: {
   "assemblies.$.warnings": {
     level: 0,
     name: "something doesn't conform to our standard"
   }
 }
})

Note the

"assemblies.$.warnings"

I found it here: http://groups.google.com/group/mongodb-user/browse_thread/thread/e8f4ea5dc1955a98#