CODEWITHSUNDEEP
mongodbnosql
Sunil
Sunil

Reputation: 624

mongodb change $group output format

I have the following document structure 

{
  "timestamp" : 13512493603565120,<br>
  "value" : 1,<br>
  "y" : 42,<br>
  "M" : 513,<br>
  "w" : 2234,<br>
  "d" : 15639,<br>
  "S" : 46918,<br>
  "h" : 375347,<br>
  "m" : 22520822,<br>
  "s" : 1351249360,<br>
  "_id" : ObjectId("508aa61100b5457c04000001"),<br>
  "__v" : 0<br>
}

I have a mongodb aggregate as follows to sum up values grouping by field y:

aggregate({ $group : {_id : "$y", value:{$sum:4}} })

This will give me

[ { "_id": 42, "value": 16 } ]

What I want now is to format this output so that it looks like this:

[ [13512493603565100, 2], [13512493605167900, 1] ]

ie:

[ [<timestamp>,<sum of value grouped by field y>], [<timestamp>,<sum of value grouped by field y>] ]

I looked at $project but I still cant figure out how I can use it to get the desired output

Upvotes: 2

Views: 236

Answers (1)

Sunil
Sunil

Reputation: 624

Not possible as of now apparently (using mapreduce or aggregate). Hope this will be added soon.

Upvotes: 1

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