Mongodb convert object values to top level string field

Question

I have the following query mongoDB

{
    "name": "juan",
    "class": {
        "name": "person"  // is the field of another collection.
    }
}

and what I want to achieve is the following

{
    "name": "juan",
    "class": "person"
}

But I need everyone's support to achieve the above.

Iyanu Adelekan · Accepted Answer · 2020-06-12 09:58:58Z

1

If all you need is for the data to be returned in the structure you specified, you can use a projection with a find query:

db.collection.find({}, { name: 1, class: '$class.name' });

Hope this helps.

answered Jun 12, 2020 at 9:58

Iyanu Adelekan

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1 Comment

Adelekam Thanks for sharing your answer.

ngShravil.py · Accepted Answer · 2020-06-12 05:59:37Z

1

I assume that you want to update the multiple documents, then bellow query will be helpful:

db.collection.update(
  { },
  [
    {
      $set: {
        'class': '$class.name'
      }
    }
  ],
  { multi:true }
)

answered Jun 12, 2020 at 5:59

ngShravil.py

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@ingShravil.py Thanks for sharing your answer.

I would like to suggest you, to be clear in the OP from next time. As in this case it was not clear whether you wanted to update or to find.

@ingShavil.py Sorry, I will be more precise with my questions, but thanks for your reply.