在mongo中映射减少

Question

我有一个“匹配”类型的文件集合谎言：

{ 
"_id": { "$oid" : "51b6eab8cd794eb62bb3e131" }, 
"_player1": { "_id": "2" }, 
"_player2": { "_id": "6" }, 
"_result": { "_sets": [ [ 6, 3 ], [ 6, 3 ], [ 5, 6 ], [ 6, 5 ] ]
},
{ 
"_id": { "$oid" : "51b6eab8cd794eb62bb3341" }, 
"_player1": { "_id": "2" }, 
"_player2": { "_id": "3" }, 
"_result": { "_sets": [ [ 6, 3 ], [ 6, 7 ], [ 7, 6 ], [ 6, 5 ] ]
},
{ 
"_id": { "$oid" : "51b6eab8cd794eb62bb3341" }, 
"_player1": { "_id": "2" }, 
"_player2": { "_id": "4" }, 
"_result": { "_sets": [ [ 6, 1 ], [ 1, 6 ], [ 6, 2 ], [ 6, 5 ] ]
}

我需要计算赢得，并列和丢失的比赛数量以及给定Id（例如2）的玩家赢得和丢失的分数

我尝试了这两个选项，但没有一个可以工作（没有提供任何结果）

选项1：

matches.group({
"initial": {
"number_of_points_won": 0,
"number_of_points_lost": 0,
"number_of_matches_won": 0,
"number_of_matches_tied": 0,
"number_of_matches_lost": 0        
},
"reduce": function(obj, prev) {
    if(obj._result!=null && obj._result._sets!=null && obj._result._sets instanceof Array){
        if(obj._result._sets.lenght>0){
            current= { number_of_points_won: 0, number_of_points_lost: 0 };
             for (var idx = 0; idx < obj._sets.length; idx++) {
                if(obj._sets[idx][0] > obj._sets[idx][1]){
                    current.number_of_points_won++;
                     prev.number_of_points_won++;
                }else if(obj._sets[idx][0] < obj._sets[idx][1]){
                    current.number_of_points_lost++;
                     prev.number_of_points_lost++;
                }
            }
            if(current.number_of_points_won > current.number_of_points_lost){
                 prev.number_of_matches_won++;
             }else if(current.number_of_points_won < current.number_of_points_lost){
                 prev.number_of_matches_lost++;
            }else {
prev.number_of_matches_tied++;
            }
        }
    }
},
"cond": {
        "matches._player1._id": "2"
        }
});

选项2：

db.matches.mapReduce(
function Map() {
var key = this._player1._id;
emit(key, {"data":[{"_sets" : this._result._sets}]}); 
},
function Reduce(key, values) {

 var reduced = {"data":[]};
for (var i in values) 
{
    var inter = values[i];
    for (var j in inter.data) {
        reduced.data.push(inter.data[j]);
    }
}

return reduced;
 }
 function Finalize(key, reduced) {
    var statistics = {"number_of_points_won": 0, "number_of_points_lost": 0, "number_of_matches_won": 0, "number_of_matches_tied":0, "number_of_matches_lost":0};
    current = { number_of_points_won: 0, number_of_points_lost: 0 };
    for (var set in reduced.data) {
       for (var idx = 0; idx < set.length; idx++) {
         if(set[idx][0] > set[idx][1]){
            current.number_of_points_won++;
            statistics.number_of_points_won++;
        }else if(set[idx][0] < set[idx][1]){
            current.number_of_points_lost++;
            statistics.number_of_points_lost++;
        }
    }
    if(current.number_of_points_won > current.number_of_points_lost){
        statistics.number_of_matches_won++;
    }else if(current.number_of_points_won < current.number_of_points_lost){
        statistics.number_of_matches_lost++;
    }else {
        statistics.number_of_matches_tied++;
       }
   }

return statistics;
 },
query : { "$where" : "{\"player1._id\" : { \"$e\" : \"2\" }}" }
);

请帮忙。我是mongo的新手。