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MongoDB\\Collection::count()
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.. deprecated:: 1.4
.. default-domain:: mongodb
.. contents:: On this page
:local:
:backlinks: none
:depth: 1
:class: singlecol
Definition
----------
.. phpmethod:: MongoDB\\Collection::count()
Count the number of documents that match the filter criteria.
.. code-block:: php
function count($filter = [], array $options = []): integer
This method has the following parameters:
.. include:: /includes/apiargs/MongoDBCollection-method-count-param.rst
The ``$options`` parameter supports the following options:
.. include:: /includes/apiargs/MongoDBCollection-method-count-option.rst
Return Values
-------------
The number of documents matching the filter criteria.
Errors/Exceptions
-----------------
.. include:: /includes/extracts/error-unexpectedvalueexception.rst
.. include:: /includes/extracts/error-unsupportedexception.rst
.. include:: /includes/extracts/error-invalidargumentexception.rst
.. include:: /includes/extracts/error-driver-runtimeexception.rst
Behavior
--------
This method is deprecated and cannot be executed within a transaction. It has
always been implemented using the :manual:`count </reference/command/count>`
command. The behavior of the ``count`` command differs depending on the options
passed to it and may or may not provide an accurate count. When no query filter
is provided, the ``count`` command provides an estimate using collection
metadata. Even when provided with a query filter the ``count`` command can
return inaccurate results with a sharded cluster if orphaned documents exist or
if a chunk migration is in progress. The
:phpmethod:`MongoDB\\Collection::countDocuments()` method avoids these sharded
cluster problems entirely when used with MongoDB 3.6+, and when a primary read
preference with older sharded clusters.
.. include:: /includes/extracts/note-bson-comparison.rst
See Also
--------
- :manual:`count </reference/command/count>` command reference in the MongoDB
manual
- :phpmethod:`MongoDB\\Collection::countDocuments()`
- :phpmethod:`MongoDB\\Collection::estimatedDocumentCount()`
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