Mongoose/MongoDB 为子文档汇总数组的字段

Question

我对 MongoDB/Mongoose 比较陌生，我不知道我应该如何获得我正在寻找的结果。基本上我有一个这样的文件：

{
    "playerId" : "",
    "sessions" : [ 
        {
            "start" : "",
            "end" : "",
            "join" : "",
            "leave" : "",
            "rounds" : [,
                {
                    "name" : "roundName",
                    "weapons" : [
                        {
                            "name" : "weaponName",
                            "kills" : 1,
                            "assits" : 1,
                            "deaths" : 1,
                            "shots" : 1,
                            "headshots" : 1
                        },
                        {
                            "name" : "weaponName",
                            "kills" : 1,
                            "assits" : 1,
                            "deaths" : 1,
                            "shots" : 1,
                            "headshots" : 1
                        }
                    ]
                },
                {
                    "name" : "roundName",
                    "weapons" : [
                        {
                            "name" : "weaponName",
                            "kills" : 1,
                            "assits" : 1,
                            "deaths" : 1,
                            "shots" : 1,
                            "headshots" : 1
                        },
                        {
                            "name" : "weaponName",
                            "kills" : 1,
                            "assits" : 1,
                            "deaths" : 1,
                            "shots" : 1,
                            "headshots" : 1
                        }
                    ]
                },
                {
                    "name" : "roundName",
                    "weapons" : [
                        {
                            "name" : "weaponName",
                            "kills" : 1,
                            "assits" : 1,
                            "deaths" : 1,
                            "shots" : 1,
                            "headshots" : 1
                        },
                        {
                            "name" : "weaponName",
                            "kills" : 1,
                            "assits" : 1,
                            "deaths" : 1,
                            "shots" : 1,
                            "headshots" : 1
                        }
                    ]
                }
            ]
        }
    ]
}

我想要的是一个查询，它为每一轮（击杀、死亡、助攻、爆头、射击）添加字段，其中包含所有武器的总和。如果可能，整个会话也应该发生同样的情况。任何帮助将不胜感激！

Answer 1

以下内容应为您提供按会话->轮次分组的统计信息列表： 这里的假设是 1) 集合的名称是射击游戏 2) 字段的名称是 $sessions.Rounds.Weapons

db.shootingGame.aggregate(
   [
       {$group: {
       _id: "$sessions.Rounds", 
       "sumkills": {$sum: "$sessions.Rounds.Weapons.kills" },
       "sumasists": {$sum: "$sessions.Rounds.Weapons.assists" },
       "sumdeaths": {$sum: "$sessions.Rounds.Weapons.deaths" },
       "sumheadshots": {$sum: "$sessions.Rounds.Weapons.headshots" },
       "sumshots": {$sum: "$sessions.Rounds.Weapons.shots" }
   }}
   ]
)

但是对于每个会话的进一步分组，您必须将此结果存储到另一个文档中并在每轮运行另一个 $sum 组