Using find() to search for nested keys in MongoDB?

MongoDBDatabaseBig Data Analytics

For find() to search for nested keys in MongoDB, you can use dot(.) notation. Following is the syntax

db.yourCollectionName.find({"yourOuterFieldName.yourInnerFieldName":"yourValue"}).pretty();

Let us first create a collection with documents:

>db.searchForNestedKeysDemo.insertOne({"ClientName":"Larry","ClientAge":28,"ClientExtra
Details":{"isEducated":true,"CountryName":"US"}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ca20e8b66324ffac2a7dc64")
}
>db.searchForNestedKeysDemo.insertOne({"ClientName":"Chris","ClientAge":29,"ClientExtra
Details":{"isEducated":false,"CountryName":"UK"}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ca20ea366324ffac2a7dc65")
}
>db.searchForNestedKeysDemo.insertOne({"ClientName":"David","ClientAge":39,"ClientExtra
Details":{"isEducated":true,"CountryName":"AUS"}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ca20eba66324ffac2a7dc66")
}

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

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

This will produce the following output

{
   "_id" : ObjectId("5ca20e8b66324ffac2a7dc64"),
   "ClientName" : "Larry",
   "ClientAge" : 28,
   "ClientExtraDetails" : {
      "isEducated" : true,
      "CountryName" : "US"
   }
}
{
   "_id" : ObjectId("5ca20ea366324ffac2a7dc65"),
   "ClientName" : "Chris",
   "ClientAge" : 29,
   "ClientExtraDetails" : {
      "isEducated" : false,
      "CountryName" : "UK"
   }
}
{
   "_id" : ObjectId("5ca20eba66324ffac2a7dc66"),
   "ClientName" : "David",
   "ClientAge" : 39,
   "ClientExtraDetails" : {
      "isEducated" : true,
      "CountryName" : "AUS"
   }
}

Following is the query to search for nested keys in MongoDB

> db.searchForNestedKeysDemo.find({"ClientExtraDetails.CountryName":"UK"}).pretty();

This will produce the following output

{
   "_id" : ObjectId("5ca20ea366324ffac2a7dc65"),
   "ClientName" : "Chris",
   "ClientAge" : 29,
   "ClientExtraDetails" : {
      "isEducated" : false,
      "CountryName" : "UK"
   }
}
raja
Published on 12-Apr-2019 12:44:12
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