crud.txt

===============
CRUD Operations
===============

.. default-domain:: mongodb

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   :class: singlecol


CRUD operations *create*, *read*, *update*, and *delete* documents. The
|php-library|'s :phpclass:`MongoDB\\Collection` class implements
MongoDB's cross-driver `CRUD specification
<https://github.com/mongodb/specifications/blob/master/source/crud/crud.
rst>`_, providing access to methods for inserting, finding, updating,
and deleting documents in MongoDB.

This document provides a general introduction to inserting, querying,
updating, and deleting documents using the |php-library|. The MongoDB
Manual's :manual:`CRUD Section </crud>` provides a more thorough
introduction to CRUD operations with MongoDB.

Insert Documents
----------------

Insert One Document
~~~~~~~~~~~~~~~~~~~

The :phpmethod:`MongoDB\\Collection::insertOne` method inserts a single
document into MongoDB and returns an instance of ``MongoDB\InsertOneResult``,
which you can use to access the IDs of the inserted document.

.. this uses the insertMany example from the method reference:

.. include:: /reference/method/MongoDBCollection-insertOne.txt
   :start-after: start-crud-include
   :end-before: end-crud-include

The output includes the ID of the inserted document.

If you include an ``_id`` value when inserting a document, MongoDB checks
to ensure that the ``_id`` value is unique for the collection. If the
``_id`` value is not unique, the insert operation fails due to a duplicate
key error.

The following example inserts a document while specifying the value for the ``_id``:

.. code-block:: php

   <?php

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

   $insertOneResult = $collection->insertOne(['_id' => 1, 'name' => 'Alice']);

   printf("Inserted %d document(s)\n", $insertOneResult->getInsertedCount());

   var_dump($insertOneResult->getInsertedId());

The output would then resemble::

   Inserted 1 document(s)
   int(1)

.. seealso:: :phpmethod:`MongoDB\\Collection::insertOne` reference.

Insert Many Documents
~~~~~~~~~~~~~~~~~~~~~

The :phpmethod:`MongoDB\\Collection::insertMany` method allows you to
insert multiple documents in one write operation and returns an instance
of ``MongoDB\InsertManyResult``, which you can use to access the
IDs of the inserted documents.

.. this uses the insertMany example from the method reference:

.. include:: /reference/method/MongoDBCollection-insertMany.txt
   :start-after: start-crud-include
   :end-before: end-crud-include

.. seealso:: :phpmethod:`MongoDB\\Collection::insertMany` reference.

Query Documents
---------------

The |php-library| provides the :phpmethod:`MongoDB\\Collection::findOne`
and :phpmethod:`MongoDB\\Collection:findMany` methods for querying
documents and the :phpmethod:`MongoDB\\Collection:aggregate`
method for performing :manual:`aggregation operations
</core/aggregation-pipeline`.

Find One Document
~~~~~~~~~~~~~~~~~

:phpmethod:`MongoDB\\Collection::findOne` returns the :term:`first
document <natural order>` that matches the query or ``null`` if no
document matches the query.

The following example searches for the document with ``_id: 94301``:

.. code-block:: php

   <?php

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

   $document = $collection->findOne(['_id' => '94301']);

   var_dump($document);

The output would then resemble::

   object(MongoDB\Model\BSONDocument)#13 (1) {
     ["storage":"ArrayObject":private]=>
     array(5) {
       ["_id"]=>
       string(5) "94301"
       ["city"]=>
       string(9) "PALO ALTO"
       ["loc"]=>
       object(MongoDB\Model\BSONArray)#12 (1) {
         ["storage":"ArrayObject":private]=>
         array(2) {
           [0]=>
           float(-122.149685)
           [1]=>
           float(37.444324)
         }
       }
       ["pop"]=>
       int(15965)
       ["state"]=>
       string(2) "CA"
     }
   }

.. seealso:: :phpmethod:`MongoDB\\Collection::findMany` reference

Find Many Documents
~~~~~~~~~~~~~~~~~~~

:phpmethod:`MongoDB\\Collection::find` returns a
:php:`MongoDB\\Driver\\Cursor <mongodb-driver-cursor>` object, which you
can iterate upon to access all matched documents.

The following example lists the documents in the ``zips`` collection
with the specified city and state values:

.. code-block:: php
                
   <?php

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

   $cursor = $collection->find(['city' => 'JERSEY CITY', 'state' => 'NJ']);

   foreach ($cursor as $document) {
       echo $document['_id'], "\n";
   }

The output would resemble::

   07302
   07304
   07305
   07306
   07307
   07310

.. seealso:: :phpmethod:`MongoDB\\Collection::find` reference

.. _php-query-projection:

Query Projection
~~~~~~~~~~~~~~~~

By default, queries in MongoDB return all fields in matching documents.
To limit the amount of data that MongoDB sends to applications, you can
include a :manual:`projection document
</tutorial/project-fields-from-query-results>` in the query operation.

.. note:: 

   MongoDB includes the ``_id`` field by default unless you explicitly
   exclude it in a projection document.

The following example finds restaurants based on the ``cuisine`` and
``borough`` fields and uses a :manual:`projection
</tutorial/project-fields-from-query-results>` to limit the fields
that are returned. It also limits the results to 5 documents.

.. code-block:: php

   <?php

   $database = new MongoDB\Client;

   $collection = $database->selectCollection('example','restaurants');

   $restaurants = $collection->find(
       [ 'cuisine' => 'Italian', 'borough' => 'Manhattan'],
       [ 
         'projection' => [
           'name' => 1, 'borough' => 1, 'cuisine' => 1,
         ],
       ]
   );

   foreach($restaurants as $restaurant) {
      var_dump($restaurant);
   };

The output would then resemble::
                
   object(MongoDB\Model\BSONDocument)#10 (1) {
     ["storage":"ArrayObject":private]=>
     array(4) {
       ["_id"]=>
       object(MongoDB\BSON\ObjectID)#8 (1) {
         ["oid"]=>
         string(24) "576023c6b02fa9281da3f983"
       }
       ["borough"]=>
       string(9) "Manhattan"
       ["cuisine"]=>
       string(7) "Italian"
       ["name"]=>
       string(23) "Isle Of Capri Resturant"
     }
   }
   object(MongoDB\Model\BSONDocument)#13 (1) {
     ["storage":"ArrayObject":private]=>
     array(4) {
       ["_id"]=>
       object(MongoDB\BSON\ObjectID)#12 (1) {
         ["oid"]=>
         string(24) "576023c6b02fa9281da3f98d"
       }
       ["borough"]=>
       string(9) "Manhattan"
       ["cuisine"]=>
       string(7) "Italian"
       ["name"]=>
       string(18) "Marchis Restaurant"
     }
   }
   object(MongoDB\Model\BSONDocument)#8 (1) {
     ["storage":"ArrayObject":private]=>
     array(4) {
       ["_id"]=>
       object(MongoDB\BSON\ObjectID)#10 (1) {
         ["oid"]=>
         string(24) "576023c6b02fa9281da3f99b"
       }
       ["borough"]=>
       string(9) "Manhattan"
       ["cuisine"]=>
       string(7) "Italian"
       ["name"]=>
       string(19) "Forlinis Restaurant"
     }
   }
   object(MongoDB\Model\BSONDocument)#12 (1) {
     ["storage":"ArrayObject":private]=>
     array(4) {
       ["_id"]=>
       object(MongoDB\BSON\ObjectID)#13 (1) {
         ["oid"]=>
         string(24) "576023c6b02fa9281da3f9a8"
       }
       ["borough"]=>
       string(9) "Manhattan"
       ["cuisine"]=>
       string(7) "Italian"
       ["name"]=>
       string(22) "Angelo Of Mulberry St."
     }
   }
   ...

Limit, Sort, and Skip Options
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In addition to :ref:`projection criteria <php-query-projection>`,
you can specify options to limit, sort, and skip documents during queries.

The following example uses the ``limit`` and ``sort`` options to query
for the five most populous zip codes in the United States:

.. code-block:: php

   <?php

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

   $cursor = $collection->find(
       [],
       [
           'limit' => 5,
           'sort' => ['pop' => -1],
       ]
   );

   foreach ($cursor as $document) {
       echo $document['_id'], "\n";
   }

The output would then resemble::

   60623: CHICAGO, IL
   11226: BROOKLYN, NY
   10021: NEW YORK, NY
   10025: NEW YORK, NY
   90201: BELL GARDENS, CA

Complex Queries with Aggregation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MongoDB's :manual:`Aggregation Framework </core/aggregation-pipeline>`
allows you to issue complex queries that filter, transform, and group
collection data. The |php-library|\'s
:phpmethod:`MongoDB\\Collection::aggregate` method returns a
:php:`traversable <traversable>` object, which you can iterate upon to
access the results of the aggregation operation. Refer to the
:phpmethod:`MongoDB\\Collection::aggregate` method's :ref:`behavior
reference <php-agg-method-behavior>` for more about the method's output.

The following example lists the 5 US states with the most zip codes
associated with them:

.. code-block:: php

   <?php

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

   $cursor = $collection->aggregate([
       ['$group' => ['_id' => '$state', 'count' => ['$sum' => 1]]],
       ['$sort' => ['count' => -1]],
       ['$limit' => 5],
   ]);

   foreach ($cursor as $state) {
       printf("%s has %d zip codes\n", $state['_id'], $state['count']);
   }

The output would then resemble::
   
   TX has 1671 zip codes
   NY has 1595 zip codes
   CA has 1516 zip codes
   PA has 1458 zip codes
   IL has 1237 zip codes

.. seealso:: :phpmethod:`MongoDB\\Collection::aggregate` reference

Update Documents
----------------

Update One Document
~~~~~~~~~~~~~~~~~~~

Use the :phpmethod:`MongoDB\\Collection::updateOne` method to update a
single document matching a filter.
:phpmethod:`MongoDB\\Collection::updateOne` returns a
``MongoDB\UpdateResult`` object, which you can use to access statistics
about the update operation.

Update methods have two required parameters: the query filter that
identifies the document or documents to update, and an update document
that specifies what updates to perform. The :phpmethod:`MongoDB\\Collection::updateOne`
reference describes each parameter in detail.

The following example inserts two documents into an empty ``users`` collection
in the ``demo`` database using the :phpmethod:`MongoDB\\Collection::insertOne`
method, and then updates the documents where the value for the ``state``
field is ``"ny"`` to include
a ``country`` field set to ``"us"``:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $collection->insertOne(['name' => 'Bob', 'state' => 'ny']);
   $collection->insertOne(['name' => 'Alice', 'state' => 'ny']);
   $updateResult = $collection->updateOne(
       ['state' => 'ny'],
       ['$set' => ['country' => 'us']]
   );

   printf("Matched %d document(s)\n", $updateResult->getMatchedCount());
   printf("Modified %d document(s)\n", $updateResult->getModifiedCount());

Since the update operation uses the
:phpmethod:`MongoDB\\Collection::updateOne` method, which updates the
first document to match the filter criteria, the results would then
resemble::

   Matched 1 document(s)
   Modified 1 document(s)

It is possible for a document to match the filter but *not be modified*
by an update, as is the case where the update sets a field's value to its
existing value, as in this example:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $collection->insertOne(['name' => 'Bob', 'state' => 'ny']);
   $updateResult = $collection->updateOne(
       ['name' => 'Bob'],
       ['$set' => ['state' => 'ny']]
   );

   printf("Matched %d document(s)\n", $updateResult->getMatchedCount());
   printf("Modified %d document(s)\n", $updateResult->getModifiedCount());

The number of matched documents and the number of *modified* documents
would therefore not be equal, and the output from the operation would
resemble::

   Matched 1 document(s)
   Modified 0 document(s)

.. seealso::

   - :phpmethod:`MongoDB\\Collection::updateOne` reference
   - :phpmethod:`MongoDB\\Collection::findOneAndUpdate` reference

Update Many Documents
~~~~~~~~~~~~~~~~~~~~~

:phpmethod:`MongoDB\\Collection::updateMany` updates one or more documents
matching the filter criteria and returns a ``MongoDB\UpdateResult`` object
that you can iterate to access statistics about the update operation.

Update methods have two required parameters: the query filter that
identifies the document or documents to update, and an update document
that specifies what updates to perform. The :phpmethod:`MongoDB\\Collection::updateMany`
reference describes each parameter in detail.

The following example inserts three documents into an empty ``users``
collection in the ``demo`` database and then uses the :query:`$set`
operator to update the documents matching the filter criteria to
include the ``country`` field with value ``"us"``:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $collection->insertOne(['name' => 'Bob', 'state' => 'ny', 'country' => 'us']);
   $collection->insertOne(['name' => 'Alice', 'state' => 'ny']);
   $collection->insertOne(['name' => 'Sam', 'state' => 'ny']);
   $updateResult = $collection->updateMany(
       ['state' => 'ny'],
       ['$set' => ['country' => 'us']]
   );

   printf("Matched %d document(s)\n", $updateResult->getMatchedCount());
   printf("Modified %d document(s)\n", $updateResult->getModifiedCount());

If an update operation results in no change to a document, such as
setting the value of the field to its current value, the number of
modified documents can be less than the number of *matched* documents.
Since the update document with ``name`` of ``"Bob"`` results in no changes
to the document, the output of the operation therefore resembles::

   Matched 3 document(s)
   Modified 2 document(s)

.. seealso:: :phpmethod:`MongoDB\\Collection::updateMany` reference

Replace Documents
~~~~~~~~~~~~~~~~~

Replacement operations are similar to update operations, but instead
of updating a document to include new fields or new field values, a
replacement operation replaces the entire document with a new document,
but retains the original document's ``_id`` value.

The :phpmethod:`MongoDB\\Collection::replaceOne` method replaces a single
document that matches the filter criteria and returns
an instance of ``MongoDB\UpdateResult`` that
you can use to access statistics about the replacement operation.

:phpmethod:`MongoDB\\Collection::replaceOne` has two required
parameters: the query filter that identifies the document or documents
to update, and a replacement document that will replace the original
document in MongoDB. The :phpmethod:`MongoDB\\Collection::replaceOne`
reference describes each parameter in detail.

.. important:: 

   Replacement operations replace all of the fields in a document
   except the ``_id`` value. To avoid accidentally overwriting or
   deleting desired fields, use the
   :phpmethod:`MongoDB\\Collection::updateOne` or
   :phpmethod:`MongoDB\\Collection::updateMany` methods to update
   individual fields in a document rather than replacing the entire
   document.

The following example inserts one document into an empty ``users`` collection
in the ``demo`` database, and then replaces that document with a new one:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $collection->insertOne(['name' => 'Bob', 'state' => 'ny']);
   $updateResult = $collection->replaceOne(
       ['name' => 'Bob'],
       ['name' => 'Robert', 'state' => 'ca']
   );

   printf("Matched %d document(s)\n", $updateResult->getMatchedCount());
   printf("Modified %d document(s)\n", $updateResult->getModifiedCount());

The output would then resemble::

   Matched 1 document(s)
   Modified 1 document(s)

.. seealso:: 

   - :phpmethod:`MongoDB\\Collection::replaceOne` reference
   - :phpmethod:`MongoDB\\Collection::findOneAndReplace` reference

Upsert
~~~~~~

Update and replace operations support an :manual:`upsert
</tutorial/update-documents/#upsert-option>` option. When ``upsert`` is
``true`` *and* no documents match the specified filter, then the
operation creates a new document and inserts it. If there *are* matching
documents, then the operation modifies or replaces the matching
document or documents.

When a document is upserted, the ID is accessible via
``MongoDB\UpdateResult::getUpsertedId()``.

The following example uses :phpmethod:`MongoDB\\Collection::updateOne`
with the ``upsert`` option set to ``true`` into an empty ``users``
collection in the ``demo`` database, therefore inserting the document
into the database:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $updateResult = $collection->updateOne(
       ['name' => 'Bob'],
       ['$set' => ['state' => 'ny']],
       ['upsert' => true]
   );

   printf("Matched %d document(s)\n", $updateResult->getMatchedCount());
   printf("Modified %d document(s)\n", $updateResult->getModifiedCount());
   var_dump($collection->findOne(['_id' => $updateResult->getUpsertedId()]));

The output would then resemble::

   Matched 0 document(s)
   Modified 0 document(s)
   object(MongoDB\Model\BSONDocument)#16 (1) {
     ["storage":"ArrayObject":private]=>
     array(3) {
       ["_id"]=>
       object(MongoDB\BSON\ObjectID)#15 (1) {
         ["oid"]=>
         string(24) "57509c4406d7241dad86e7c3"
       }
       ["name"]=>
       string(3) "Bob"
       ["state"]=>
       string(2) "ny"
     }
   }

Delete Documents
----------------

Delete One Document
~~~~~~~~~~~~~~~~~~~


The :phpmethod:`MongoDB\\Collection::deleteOne` method deletes a single
document that matches the filter criteria and returns a
``MongoDB\DeleteResult`` object that you can use to access statistics
about the delete operation. If multiple documents match the filter
criteria, :phpmethod:`MongoDB\\Collection::deleteOne` deletes the
:term:`first <natural order>` matching document.

:phpmethod:`MongoDB\\Collection::deleteOne` has one required parameter:
a query filter that specifies the document to delete. Refer to the
:phpmethod:`MongoDB\\Collection::deleteOne` reference for full method documentation.


The following operation deletes the first document where the ``state``
value is ``ny``:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $collection->insertOne(['name' => 'Bob', 'state' => 'ny']);
   $collection->insertOne(['name' => 'Alice', 'state' => 'ny']);
   $deleteResult = $collection->deleteOne(['state' => 'ny']);

   printf("Deleted %d document(s)\n", $deleteResult->getDeletedCount());

The output would then resemble::

   Deleted 1 document(s)

.. seealso:: :phpmethod:`MongoDB\\Collection::deleteOne` reference.

Delete Many Documents
~~~~~~~~~~~~~~~~~~~~~

:phpmethod:`MongoDB\\Collection::deleteMany` deletes all of the
documents that match the filter criteria and returns a
``MongodB\DeleteResult`` object that you can use to access statistics
about the delete op eration.

:phpmethod:`MongoDB\\Collection::deleteMany` has one required
parameter: a query filter that specifies the document to delete. Refer
to the :phpmethod:`MongoDB\\Collection::deleteMany` reference for full
method documentation.


The following operation deletes all of the documents where the
``state`` field has value ``"ny"``:

.. code-block:: php

   <?php

   $collection = (new MongoDB\Client)->demo->users;
   $collection->drop();

   $collection->insertOne(['name' => 'Bob', 'state' => 'ny']);
   $collection->insertOne(['name' => 'Alice', 'state' => 'ny']);
   $deleteResult = $collection->deleteMany(['state' => 'ny']);

   printf("Deleted %d document(s)\n", $deleteResult->getDeletedCount());

The output would then resemble::

   Deleted 2 document(s)

.. seealso:: :phpmethod:`MongoDB\\Collection::deleteMany` reference