What does createdCollectionAutomatically mean in MongoDB?

If a collection does not exist then MongoDB creates a collection in indexing part. The createdCollectionAutomatically tells that the operation created a collection.

For our example, let us create a collection with an index −

> db.createCollectionDemo.createIndex({"ClientCountryName":1});

This will produce the following output −

{
   "createdCollectionAutomatically" : true,
   "numIndexesBefore" : 1,
   "numIndexesAfter" : 2,
   "ok" : 1
}

Let us create a collection with documents −

> db.createCollectionDemo.insertOne({"ClientName":"Larry","ClientCountryName":"US"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd2950be3526dbddbbfb612")
}

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

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

This will produce the following output −

{
   "_id" : ObjectId("5cd2950be3526dbddbbfb612"),
   "ClientName" : "Larry",
   "ClientCountryName" : "US"
}