=====================================
MongoDB\\Database::createCollection()
=====================================

.. default-domain:: mongodb

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Definition
----------

.. phpmethod:: MongoDB\\Database::createCollection()

   Explicitly creates a collection.

   .. code-block:: php

      function createCollection($collectionName, array $options = []): array|object

   MongoDB creates collections implicitly when you first reference the
   collection in a command, such as when inserting a document into a new
   collection. You may also explicitly create a collection with specific options
   using the :phpmethod:`MongoDB\\Database::createCollection()` method, or using
   :manual:`db.createCollection() </reference/method/db.createCollection>` in
   the :program:`mongo` shell.

   Explicitly creating collections enables you to create
   :manual:`capped collections </core/capped-collections>`, specify
   :manual:`document validation criteria </core/document-validation>`,
   or configure your storage engine or indexing options.

   This method has the following parameters:

   .. include:: /includes/apiargs/MongoDBDatabase-method-createCollection-param.rst

   The ``$options`` parameter supports the following options:

   .. include:: /includes/apiargs/MongoDBDatabase-method-createCollection-option.rst

   Note that not all options are available on all versions of MongoDB. Document
   validation, for example, was added in MongoDB 3.2; similarly, the WiredTiger
   storage engine is available only for MongoDB 3.0 and later. Refer to the
   :manual:`create </reference/command/create>` command reference in the MongoDB
   manual for compatibility considerations.

Return Values
-------------

An array or object with the result document of the :manual:`create
</reference/command/create>` command.

Errors/Exceptions
-----------------

.. include:: /includes/extracts/error-unsupportedexception.rst
.. include:: /includes/extracts/error-invalidargumentexception.rst
.. include:: /includes/extracts/error-driver-runtimeexception.rst

Example
-------

The following example creates a ``users`` collection in the ``demo``
database with document validation criteria:

.. code-block:: php

   <?php

   $db = (new MongoDB\Client)->demo;

   $result = $db->createCollection('users', [
       'validator' => [
           'username' => ['$type' => 'string'],
           'email' => ['$regex' => '@mongodb\.com$'],
       ],
   ]);

   var_dump($result);

The output would then resemble::

   object(MongoDB\Model\BSONDocument)#11 (1) {
     ["storage":"ArrayObject":private]=>
     array(1) {
       ["ok"]=>
       float(1)
     }
   }

See Also
--------

- :manual:`create </reference/command/create>` command reference in the MongoDB
  manual
- :manual:`db.createCollection() </reference/method/db.createCollection>`
