=================================
MongoDB\\Client::selectDatabase()
=================================

.. default-domain:: mongodb

.. contents:: On this page
   :local:
   :backlinks: none
   :depth: 1
   :class: singlecol

Definition
----------

.. phpmethod:: MongoDB\\Client::selectDatabase($databaseName, $options)

   Selects a database on the :program:`mongod` instance to which your
   application is connected.
   
   .. code-block:: php

      function selectDatabase($databaseName array $options = []): MongoDB\Database

   :phpmethod:`MongoDB\\Client::selectDatabase` has the following parameters:

   .. include:: /includes/apiargs/MongoDBClient-method-selectDatabase-param.rst

   The following table describes the options that
   :phpmethod:`MongoDB\\Client::selectDatabase` can accept.

   .. include:: /includes/apiargs/MongoDBClient-method-selectDatabase-option.rst

Output
------

Returns a :phpclass:`MongoDB\\Database` object.

Example
-------

The following example selects the ``demo`` database:

.. code-block:: php

   <?php

   $client = new MongoDB\Client;

   $db = $client->selectDatabase('demo');

The following examples selects the ``demo`` database with a custom read
preference:

.. code-block:: php

   <?php

   $client = new MongoDB\Client;

   $db = $client->selectDatabase(
       'demo',
       [
           'readPreference' => new MongoDB\Driver\ReadPreference(MongoDB\Driver\ReadPreference::RP_SECONDARY),
       ]
   );

.. seealso::

   - :phpmethod:`Collection::__construct`
   - :phpmethod:`MongoDB\\Client::__get`