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how to group sub array inside document using mongodb

Posted on 2017-04-09
Medium Priority
Last Modified: 2017-04-16
hi, i have the following document on mongodb

name: "john",
state: "GA",
city: [
     {"atlanta", 30350},
     {"atlanta", 30351},
     {"atlanta", 30352},
     {"marietta", 45093}

how do i aggregate the array of citys and get a document like this:

name: "john",
state: "GA",
city: [
     {"atlanta", "30350, 30351, 30352"},
     {"marietta", "45093"}
Question by:rafaelrgl
  • 3
LVL 11

Expert Comment

by:Nitin Sontakke
ID: 42085989
I am almost certainly (not yet) an expert on MongoDB, however, I suspect if you can do that without getting data back, manipulate it and put it back again.

How many records (Ooops! documents) are involved here? Please wait for others to comment as well.

Accepted Solution

rafaelrgl earned 0 total points
ID: 42088568
{ $concatArrays: [ [ "hello", " "], [ "world" ] ] }

Author Closing Comment

ID: 42094660
that is the right solution for it.

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