MongoDB query to return only embedded document?

It is not possible to return only embedded document. However, it will return all the documents from a collection. Let us first implement the following query to create a collection with documents

>db.queryToEmbeddedDocument.insertOne({"UserName":"Larry","PostDetails":[{"UserMessage":"Hello","UserLikes":8},{"UserMessage":"Hi","UserLikes":6},{"UserMessage":"Good Morning","UserLikes":12},{"UserMessage":"Awesome","UserLikes":4}]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5c988a9f330fd0aa0d2fe4bd")
}

Following is the query to display all documents from a collection with the help of find() method

> db.queryToEmbeddedDocument.find().pretty();

This will produce the following output

{
   "_id" : ObjectId("5c988a9f330fd0aa0d2fe4bd"),
   "UserName" : "Larry",
   "PostDetails" : [
      {
         "UserMessage" : "Hello",
         "UserLikes" : 8
      },
      {
         "UserMessage" : "Hi",
         "UserLikes" : 6
      },
      {
         "UserMessage" : "Good Morning",
         "UserLikes" : 12
      },
      {
         "UserMessage" : "Awesome",
         "UserLikes" : 4
      }
   ]
}

Following is the query to return all the documents from a collection

> db.queryToEmbeddedDocument.find({"PostDetails.UserLikes": {$gte: 8}},{PostDetails:1}).pretty();

This will produce the following output

{
   "_id" : ObjectId("5c988a9f330fd0aa0d2fe4bd"),
   "PostDetails" : [
      {
         "UserMessage" : "Hello",
         "UserLikes" : 8
      },
      {
         "UserMessage" : "Hi",
         "UserLikes" : 6
      },
      {
         "UserMessage" : "Good Morning",
         "UserLikes" : 12
      },
      {
         "UserMessage" : "Awesome",
         "UserLikes" : 4
      }
   ]
}

Look at the above sample output, we are getting all the documents while we want only those documents in which “UserLikes” are greater than or equal to 8.

George John

Published on 11-Apr-2019 12:28:36