CODEWITHSUNDEEP
mongodbaggregation-frameworkaggregate
upInCloud
upInCloud

Reputation: 1009

MongoDb aggregate on nested object field

I have a collection of documents of format

{
    "name": <name>,
    "status": {
        "statusId": <can be a number which I want to aggregate like 1/2/3/4>
    }
}

I want to have an aggregation by status.statusId - e.g. 5 documents have status.statusId = 0, 3 documents have status.statusId = 5 etc.

I tried

db.getCollection("users").aggregate([
{
    $group: { _id: { "status":  { "statusId": "$statusId" }}, count: {$sum:1} }
}
])

but it doesn't work.

Where am I going wrong?

Upvotes: 1

Views: 1589

Answers (1)

mickl
mickl

Reputation: 49985

You should use the dot notation for your _id

db.getCollection("users").aggregate([
   {
      $group: { _id:  "$status.statusId", count: {$sum:1} }
   }
])

Upvotes: 3

Related Questions