si la fonction mongodb mapreduce accepte la valeur calculée du document en tant que mappeur

Question

J'utilise MongoDB version 2.6.10. Voici la structure de collecte. J'utilise la fonction MapReduce pour regrouper les noms de l'utilisateur en fonction (créé (sauf secondes), event_name.

{ 
    "_id" : ObjectId("59c11d79078dc54153c36ee8"), 
    "event_name" : "notification", 
    "created" : ISODate("2017-09-19T13:36:57.252Z"), 
    "sender_name" : "nathan", 
    "user_name": "Ragul"", 
} 
{ 
    "_id" : ObjectId("59c11d79078dc54153c36eeb"), 
    "event_name" : "notification", 
    "created" : ISODate("2017-09-19T13:36:57.772Z"), 
    "sender_name" : "parmesh", 
    "user_name": "Ram", 
} 
{ 
    "_id" : ObjectId("59c11d7a078dc54153c36ef0"), 
    "event_name" : "notification", 
    "created" : ISODate("2017-09-19T13:36:58.554Z"), 
    "sender_name" : "nathan", 
    "user_name": "Ram", 

} 
{ 
    "_id" : ObjectId("59c11d7a078dc54153c36ef1"), 
    "event_name" : "message", 
    "created" : ISODate("2017-09-19T13:36:58.577Z"), 
    "sender_name" : "nathan", 
    "user_name": "Ragul"", 
} 

Ci-dessous est ma requête en utilisant la fonction MapReduce. Ma question est de savoir si nous pouvons utiliser la date calculée en mappeur. Aidez-moi vos suggestions

var mapfn = function(){ 
    if (this.event_name == "message"){ 
     name = this.recipient_name 
    } 
    else if ((this.event_name == "notification") && (this.other_status == true)){ 
     name = this.sender_name 
    } 
    else if ((this.event_name == "notification") && (this.other_status == false)){ 
     name = "You" 
    } 
    this.cre = {$subtract:[this.created,{$add:[{$multiply:[{$second:this.created},1000]},{$millisecond:this.created}]}]} 
    emit({"event_name": this.event_name, "created": this.cre}, name) 
} 

var redfun = function(key, value){ 
    return Array.append(value) 
} 

db.getCollection('users').mapReduce(mapfn, redfun, {out: "example"}).find() 

Answer 1

ici au lieu calculer la date en utilisant l'expression MongoDB, je essayé d'utiliser javascript pour éliminer les secondes puis je cartographié alors son travaillé.

var mapfn = function(){ 
    if (this.event_name == "message"){ 
     name = this.recipient_name 
    } 
    else if ((this.event_name == "notification") && (this.other_status == true)){ 
     name = this.sender_name 
    } 
    else if ((this.event_name == "notification") && (this.other_status == false)){ 
     name = "You" 
    } 
    this.created.setSeconds(0); 
    this.created.setMilliseconds(0); 
    emit({"event_name": this.event_name, "created": this.created}, name) 
} 

var redfun = function(key, value){ 
    var names = value.join(",") 
    return names 
} 

db.users.mapReduce(mapfn, redfun, {out: "example"}).find()