In this chapter, we will learn how to delete a document using MongoDB.

The remove() Method

MongoDB”s remove() method is used to remove a document from the collection. remove() method accepts two parameters. One is deletion criteria and second is justOne flag.

• deletion criteria − (Optional) deletion criteria according to documents will be removed.

• justOne − (Optional) if set to true or 1, then remove only one document.

Syntax

Basic syntax of remove() method is as follows −

>db.COLLECTION_NAME.remove(DELLETION_CRITTERIA)

Example

Consider the mycol collection has the following data.

{_id : ObjectId("507f191e810c19729de860e1"), title: "MongoDB Overview"},
{_id : ObjectId("507f191e810c19729de860e2"), title: "NoSQL Overview"},
{_id : ObjectId("507f191e810c19729de860e3"), title: "Tutorials Point Overview"}

Following example will remove all the documents whose title is ”MongoDB Overview”.

>db.mycol.remove({''title'':''MongoDB Overview''})
WriteResult({"nRemoved" : 1})
> db.mycol.find()
{"_id" : ObjectId("507f191e810c19729de860e2"), "title" : "NoSQL Overview" }
{"_id" : ObjectId("507f191e810c19729de860e3"), "title" : "Tutorials Point Overview" }

Remove Only One

If there are multiple records and you want to delete only the first record, then set justOne parameter in remove() method.

>db.COLLECTION_NAME.remove(DELETION_CRITERIA,1)

Remove All Documents

If you don”t specify deletion criteria, then MongoDB will delete whole documents from the collection. This is equivalent of SQL”s truncate command.

> db.mycol.remove({})
WriteResult({ "nRemoved" : 2 })
> db.mycol.find()
>

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