Handling optional/empty data in MongoDB?

In order to handle empty data, you can use $ne operator. Let us create a collection with documents. Following is the query

>db.handlingAndEmptyDataDemo.insertOne({"StudentName":"John","StudentCountryName":""}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9cbd5ca629b87623db1b12") } >db.handlingAndEmptyDataDemo.insertOne({"StudentName":"John","StudentCountryName":null}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9cbd6ba629b87623db1b13") } > db.handlingAndEmptyDataDemo.insertOne({"StudentName":"John"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9cbd71a629b87623db1b14") }

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

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

This will produce the following output

{    "_id" : ObjectId("5c9cbd5ca629b87623db1b12"),    "StudentName" : "John",    "StudentCountryName" : "" } {    "_id" : ObjectId("5c9cbd6ba629b87623db1b13"),    "StudentName" : "John",    "StudentCountryName" : null } { "_id" : ObjectId("5c9cbd71a629b87623db1b14"), "StudentName" : "John" }

Following is the query to handle empty data using $ne

> db.handlingAndEmptyDataDemo.find({StudentCountryName: {$ne: null}});

This will produce the following output

{ "_id" : ObjectId("5c9cbd5ca629b87623db1b12"), "StudentName" : "John", "StudentCountryName" : "" }