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.