Retrieving a Subset of Fields from MongoDB

To retried a subset of fields, use dot notation in find(). Let us create a collection with documents −

> db.demo307.insertOne({ ...   "CleintId":101, ...   "ClientDetails":{"ClientFirstName":"Chris","Age":34}, ...   "ClientCountryName":"US" ...} ...); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4eab88f8647eb59e56203c") } > db.demo307.insertOne({ ...   "CleintId":102, ...   "ClientDetails":{"ClientFirstName":"David","Age":31}, ...   "ClientCountryName":"UK" ...} ...); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4eab97f8647eb59e56203d") }

Display all documents from a collection with the help of find() method −

>  db.demo307.find();

This will produce the following output −

{ "_id" : ObjectId("5e4eab88f8647eb59e56203c"), "CleintId" : 101, "ClientDetails" : { "ClientFirstName" : "Chris", "Age" : 34 }, "ClientCountryName" : "US" } { "_id" : ObjectId("5e4eab97f8647eb59e56203d"), "CleintId" : 102, "ClientDetails" : { "ClientFirstName" : "David", "Age" : 31 }, "ClientCountryName" : "UK" }

Following is the query to retrieve a subset of fields from MongoDB −

> db.demo307.find( {"ClientDetails.ClientFirstName":'David'}, {"ClientDetails.Age" : 0,"ClientCountryName":0,CleintId:0,_id:0});

This will produce the following output −

{ "ClientDetails" : { "ClientFirstName" : "David" } }