If you have a view in a MongoDB database that you’d prefer to be a collection, you’re in the right place.

Below is an example of converting a view to a collection in MongoDB.

Example

This example demonstrates how to convert a view into a collection using the MongoDB Database Tools mongodump and mongorestore.

If you don’t have these tools installed, see the MongoDB installation guide.

Find a View

First, let’s take a look at the views and collections in the current database:

show collections

Result:

employees
owners
pets
system.views
v_pettypes

In this case, v_pettypes is actually a view.

We can verify that it’s a view with the following query:

db.getCollectionInfos( { "name": "v_pettypes"} )

Result:

[
	{
		"name" : "v_pettypes",
		"type" : "view",
		"options" : {
			"viewOn" : "pets",
			"pipeline" : [
				{
					"$group" : {
						"_id" : "$type"
					}
				}
			]
		},
		"info" : {
			"readOnly" : true
		}
	}
]

We know it’s a view because the type field has a value of view.

Convert the View to a Collection

We can now go ahead and convert that view into a collection. We can do this with the MongoDB Database Tools mongodump and mongorestore.

We’ll use mongodump to export the view, and mongorestore to restore it. Specifically, we’ll pipe the mongodump output stream into mongorestore. That way we can do the whole thing at once.

Here’s the code:

mongodump --archive --db=PetHotel --collection=v_pettypes --viewsAsCollections | mongorestore --archive  --nsFrom='PetHotel.v_pettypes' --nsTo='PetHotel.pettypes'

You need to run that code from your system’s command line (e.g. a new Terminal or Command Prompt window). Don’t run it from the mongo shell.

Running that code converted the v_pettypes view to a collection called pettypes in the same database.

Strictly speaking, we didn’t actually convert the view to a collection. We simply used the --viewsAsCollections argument to dump the view as a collection, then we restored that collection back to the database. Therefore original view still exists.

When you export a view as a collection, mongodump produces a BSON file containing the documents in the view. If you use mongorestore to restore the produced BSON file, the view will be restored as a collection.

Without using the --viewsAsCollections argument, mongodump exports each view’s metadata. If you include a view’s metadata file in a mongorestore operation, the view is recreated.

Using --viewsAsCollections also omits all standard collections.

Check the Results

Let’s take another look at our views and collections.

show collections

Result:

employees
owners
pets
pettypes
system.views
v_pettypes

So we can see that a new collection called pettypes exists, and the original view still exists.

We can verify that pettypes is a collection (and not a view) as follows:

db.getCollectionInfos( { "name": "pettypes"} )

Result:

[
	{
		"name" : "pettypes",
		"type" : "collection",
		"options" : {
			
		},
		"info" : {
			"readOnly" : false,
			"uuid" : UUID("d183c7e4-44bc-4656-b272-7ad707f8dc62")
		},
		"idIndex" : {
			"v" : 2,
			"key" : {
				"_id" : 1
			},
			"name" : "_id_"
		}
	}
]

We can see that the type field contains a value of collection, which means that it’s a collection.

Drop the Original View

At this stage we now have the choice of either deleting the original view or leaving it there.

We can drop it like this:

db.v_pettypes.drop()

Now if we check the collections, we can see that the original view is gone and the new collection remains.

show collections

Result:

employees
owners
pets
pettypes
system.views