db.getSiblingDB.txt

=================
db.getSiblingDB()
=================

.. default-domain:: mongodb

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Definition
----------

.. method:: db.getSiblingDB(<database>)


   .. list-table::
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      * - Parameter
   
        - Type
   
        - Description
   
      * - ``database``
   
        - string
   
        - The name of a MongoDB database.
          
          
   


   :returns: A database object.

   Used to return another database without modifying the
   ``db`` variable in the shell environment.

Example
-------

You can use :method:`db.getSiblingDB()` as an alternative to the ``use
<database>`` helper. This is particularly useful when writing scripts
using the :binary:`~bin.mongo` shell where the ``use`` helper is not
available. Consider the following sequence of operations:

.. code-block:: javascript

   db = db.getSiblingDB('users')
   db.active.count()

This operation sets the ``db`` object to point to the database named
``users``, and then returns a :doc:`count
</reference/method/db.collection.count>` of the collection named
``active``. You can create multiple ``db`` objects, that refer to
different databases, as in the following sequence of operations:

.. code-block:: javascript

   users = db.getSiblingDB('users')
   records = db.getSiblingDB('records')

   users.active.count()
   users.active.findOne()

   records.requests.count()
   records.requests.findOne()

This operation creates two ``db`` objects referring to different
databases (i.e. ``users`` and ``records``) and then returns a
:doc:`count </reference/method/db.collection.count>` and an
:doc:`example document </reference/method/db.collection.findOne>` from
one collection in that database (i.e. ``active`` and ``requests``
respectively.)