How to aggregate the values of a field into an array?

Question

Let's take a collection named values which contains the following documents.

{ "_id" : 1, "name" : "value1", "x" : 1, "y" : 2 }
{ "_id" : 2, "name" : "value1", "x" : 2, "y" : 2 }
{ "_id" : 3, "name" : "value1", "z" : 10 }
{ "_id" : 4, "name" : "value1", "z" : 20 }
{ "_id" : 5, "name" : "value2", "x" : 8, "y" : 3 }
{ "_id" : 6, "name" : "value2", "x" : 8, "y" : 3 }
{ "_id" : 7, "name" : "value2", "z" : 15 }

Here, if I query based on name, take value1, then I should get the following single document.

{ "name" : "value1", "x" : [ 1, 2 ], "y" : [ 2, 2 ], "z" : [ 10, 20 ] }

I think this has something to do with aggregation. But I have no idea how to do it. Is there any way to achieve this behavior?

Ashh · Accepted Answer · 2020-06-11 11:39:41Z

2

You can use below aggregtion

db.collection.aggregate([
  {
    $match: {
      name: "value1"
    }
  },
  {
    $group: {
      _id: "$name",
      x: {
        "$push": "$x"
      },
      y: {
        "$push": "$y"
      },
      z: {
        "$push": "$z"
      }
    }
  }
])

MongoPlayground

answered Jun 11, 2020 at 11:39

Ashh

46.6k16 gold badges111 silver badges137 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Shane John Paul Over a year ago

Is it possible to add a name field to the resulting document?

Shane John Paul Over a year ago

Yeah. But what if I match the documents using multiple common fields like name and I want to include them in the resulting document?

Shane John Paul Over a year ago

I got it. If we use $first, we can still have the fields we want.

Ashh Over a year ago

@L.ShaneJohnPaulNewton Yes stackoverflow.com/questions/54440636/…

Collectives™ on Stack Overflow

How to aggregate the values of a field into an array?

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related