I have an array of documents as such:
"players" : [
    {
        "approved" : true,
        "isGM" : true,
        "user" : {
            "userID" : 1,
            "username" : "User 1"
        }
    }
],
I'm trying to rename userID to userId with
db.games.update({}, { $rename: { 'players.user.userID': 'players.user.userId' } });
But when I do, I get cannot use the part (players of players.user.userID) to traverse the element. How can I rename these fields and why the current method doesn't work?
 
    