Sailsjs native with Mapreduce - mongodb

Question

I am working on sailsjs project, i just looking for suggestion to achieve the below output to make best performance with code samples.
My existing collection having this below document.
[{
"word" : "DAD",
"createdAt":"6/10/2016 7:25:59 AM",
"gamescore":1
},
{
"word" : "SAD",
"createdAt":"6/09/2016 7:25:59 AM",
"gamescore":1
},
{
"word" : "PAD",
"createdAt":"6/10/2016 8:25:59 AM",
"gamescore":1
}]
I need the below output which is something like this.
[{
"word" : "A",
"repeatedTimes" : "3",
"LatestRepeatedTime": "6/10/2016 8:25:59 AM"
},
{
"word" : "D",
"repeatedTimes" : "4",
"LatestRepeatedTime": "6/10/2016 8:25:59 AM"
},
{
"word" : "P",
"repeatedTimes" : "1",
"LatestRepeatedTime": "6/10/2016 8:25:59 AM"
},
{
"word" : "S",
"repeatedTimes" : "1",
"LatestRepeatedTime": "6/09/2016 8:25:59 AM"
}]
For the above scenario i implemented the below code to fetch, but it is not working at find query.
var m = function () {
var words = this.word;
if (words) {
for (var i = 0; i < words.length; i++) {
emit(words[i], 1);
}
}
}
var r = function (key, values) {
var count = 0;
values.forEach(function (v) {
count += v;
});
return count;
}
console.log(req.params.childid);
Activity.native(function (err, collection) {
console.log("hello");
collection.mapReduce(m, r, {
out: {merge: "words_count" + "_" + "575a4952bfb2ad01481e9060"}
}, function (err, result) {
Activity.getDB(function (err, db) {
var colname = "words_count" + "_" + "575a4952bfb2ad01481e9060";
var natCol = db.collection('words_count' + "_" + "575a4952bfb2ad01481e9060");
natCol.find({},..... **is not working**
natCol.count({}, function (err, docs) {
console.log(err);
console.log(docs);
res.ok(docs);
});
});
});
});
Answer:
natCol.aggregate([
{
$project:
{
_id: "$_id" ,
value:"$value"
}
}
], function(err, data){
console.log(data);
res.ok(data);
});

Answer 1

You could try the following
var m = function () {
if (this.word) {
for (var i = 0; i < this.word.length; i++) {
emit(this.word[i], {
"repeatedTimes": 1,
"LatestRepeatedTime": this.createdAt
});
}
}
};
var r = function (key, values) {
var obj = {};
values.forEach(function(value) {
printjson(value);
Object.keys(value).forEach(function(key) {
if (!obj.hasOwnProperty(key)) obj[key] = 0;
if (key === "repeatedTimes") obj[key] += value[key];
});
obj["LatestRepeatedTime"] = value["LatestRepeatedTime"];
});
return obj;
};
var opts = { out: {inline: 1} };
Activity.native(function (err, collection) {
collection.mapReduce(m, r, opts, function (err, result) {
console.log(err);
console.log(result);
res.ok(result);
});
});