To restrict returned data, use find(). The values 0 and 1 for fields would decide what all field values would be visible or hidden.
Let us create a collection with documents −
> db.demo330.insertOne({"Id":101,"Name":"Chris","Age":21}); { "acknowledged" : true, "insertedId" : ObjectId("5e52149ff8647eb59e562081") } > db.demo330.insertOne({"Id":102,"Name":"Sam","Age":24}); { "acknowledged" : true, "insertedId" : ObjectId("5e5214aaf8647eb59e562082") } > db.demo330.insertOne({"Id":103,"Name":"David","Age":28}); { "acknowledged" : true, "insertedId" : ObjectId("5e5214b3f8647eb59e562083") } > db.demo330.insertOne({"Id":104,"Name":"Bob","Age":23}); . { "acknowledged" : true, "insertedId" : ObjectId("5e5214bdf8647eb59e562084") }
Display all documents from a collection with the help of find() method −
> db.demo330.find();
This will produce the following output −
{ "_id" : ObjectId("5e52149ff8647eb59e562081"), "Id" : 101, "Name" : "Chris", "Age" : 21 } { "_id" : ObjectId("5e5214aaf8647eb59e562082"), "Id" : 102, "Name" : "Sam", "Age" : 24 } { "_id" : ObjectId("5e5214b3f8647eb59e562083"), "Id" : 103, "Name" : "David", "Age" : 28 } { "_id" : ObjectId("5e5214bdf8647eb59e562084"), "Id" : 104, "Name" : "Bob", "Age" : 23 }
Following is the query to restrict returned data in MongoDB. Only field “Name” would be visible since 1 is set −
> db.demo330.find({},{Name:1});
This will produce the following output −
{ "_id" : ObjectId("5e52149ff8647eb59e562081"), "Name" : "Chris" } { "_id" : ObjectId("5e5214aaf8647eb59e562082"), "Name" : "Sam" } { "_id" : ObjectId("5e5214b3f8647eb59e562083"), "Name" : "David" } { "_id" : ObjectId("5e5214bdf8647eb59e562084"), "Name" : "Bob" }