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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" : "" }
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