我有一系列在各种channel上进行的端点测试。集合中的示例文档是:{"_id":ObjectId("59959b30c699811077751b12"),"teststatus":"Fail","channelname":"HouseController","timestamp":ISODate("2017-08-17T13:15:53.170Z"),"testid":"llpKIgIfiiquqkSApwNn"}我正在查询这个以投影这样的结果:[{"Fail":20,"SuccessCount":30,"Total":50,"channel":"c3"},...但我对成功率和失败率

我有一系列在各种channel上进行的端点测试。集合中的示例文档是:{"_id":ObjectId("59959b30c699811077751b12"),"teststatus":"Fail","channelname":"HouseController","timestamp":ISODate("2017-08-17T13:15:53.170Z"),"testid":"llpKIgIfiiquqkSApwNn"}我正在查询这个以投影这样的结果:[{"Fail":20,"SuccessCount":30,"Total":50,"channel":"c3"},...但我对成功率和失败率