CODEWITHSUNDEEP
node.jsmongodbmongoose
abhaygarg12493
abhaygarg12493

Reputation: 1605

Sum of a particular field by matching particular field

we are using mongoose

We have this collection

{
    "_id" : ObjectId("5596c195336cbb042728c83b"),
    "cameraId" : ObjectId("559514d3f20fb7e959a5b078"),
    "orignalFilePath" : "/opt/safecamz/recording/55950adaa24f46d255acfe90/559514d3f20fb7e959a5b078/1A01270PAA0012/2000-01-09/001/dav/23/23.26.09-23.27.33[M][0@0][0].dav",
    "recordingDuration" : 11.042,
    "recordingLocation" : "/opt/safecamz/recording/55950adaa24f46d255acfe90/559514d3f20fb7e959a5b078/video/23.26.09-23.27.33[M][0@0][0].mp4",
    "userId" : ObjectId("55950adaa24f46d255acfe90"),
    "created" : ISODate("2015-07-03T17:08:37.537Z"),
    "recordingSize" : "1259.3857421875",
    "recordingWowzaUrl" : "55950adaa24f46d255acfe90/559514d3f20fb7e959a5b078/video/23.26.09-23.27.33[M][0@0][0].mp4",
    "recordingName" : "23.26.09-23.27.33[M][0@0][0].mp4",
    "__v" : 0
}

Now we want to add recordingSize by userId for example if there are 10,000 recording then sum of recordingSize where userId=ObjectId("55950adaa24f46d255acfe90")

we try to use $sum but we are unable to get correct output

Upvotes: 0

Views: 35

Answers (1)

Alex V
Alex V

Reputation: 1155

You can use aggregation. Let's assume sample data derived from your sample:

> db.recordings.find({}, {_id: 0, userId: 1, recordingSize: 1, recordingDuration:1})
{ "recordingDuration" : 11.042, "userId" : ObjectId("55950adaa24f46d255acfe90"), "recordingSize" : "1259.3857421875" }
{ "recordingDuration" : 11.042, "userId" : ObjectId("55950adaa24f46d255acfe90"), "recordingSize" : "3000.3857421875" }

Let's try recordingDuration first and see the sum in totalDuration:

> db.recordings.aggregate([{$project: {userId:1, recordingDuration:1}}, {$group: { _id: '$userId', totalDuration: { $sum: '$recordingDuration' }}}])
{ "_id" : ObjectId("55950adaa24f46d255acfe90"), "totalDuration" : 22.084 }

The problem is that recordingSize is a String, that's why $sum will not work:

> db.recordings.aggregate([{$project: {userId:1, recordingSize:1}}, {$group: { _id: '$userId', totalSize: { $sum: '$recordingSize' }}}])
{ "_id" : ObjectId("55950adaa24f46d255acfe90"), "totalSize" : 0 }

More details here: $sum (aggregation).

Upvotes: 1

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