How to delete all the documents from a collection in MongoDB?

If you want to delete all documents from the collection, you can use deleteMany(). Let us first create a collection and insert some documents to it:

> db.deleteDocumentsDemo.insert({"Name":"Larry","Age":23});
WriteResult({ "nInserted" : 1 })
> db.deleteDocumentsDemo.insert({"Name":"Mike","Age":21});
WriteResult({ "nInserted" : 1 })
> db.deleteDocumentsDemo.insert({"Name":"Sam","Age":24});
WriteResult({ "nInserted" : 1 })

Now display all the documents from the collection. The query is as follows:

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

The following is the output:

{
   "_id" : ObjectId("5c6ab0e064f3d70fcc914805"),
   "Name" : "Larry",
   "Age" : 23
}
{
   "_id" : ObjectId("5c6ab0ef64f3d70fcc914806"),
   "Name" : "Mike",
   "Age" : 21
}
{
   "_id" : ObjectId("5c6ab0f864f3d70fcc914807"),
   "Name" : "Sam",
   "Age" : 24
}

The query is as follows:

> db.deleteDocumentsDemo.deleteMany({});

The following is the output:

{ "acknowledged" : true, "deletedCount" : 3 }

Look at the above sample output. Right now, we do not have any documents in the collection ‘deleteDocumentsDemo’ i.e. we have successfully deleted all the documents using the deleteMany() method.

Krantik Chavan

Published on 18-Mar-2019 15:18:00