============= Upgrade Guide ============= .. default-domain:: mongodb .. contents:: On this page :local: :backlinks: none :depth: 2 :class: singlecol Overview -------- The |php-library| and underlying :php:`mongodb extension <mongodb>` have notable API differences from the legacy :php:`mongo extension <mongo>`. This page will summarize those differences for the benefit of those upgrading from the legacy driver. Additionally, a community-developed `mongo-php-adapter <https://github.com/alcaeus/mongo-php-adapter>`_ library exists, which implements the `mongo extension <http://php.net/mongo>`_ API using this library and the new driver. While this adapter library is not officially supported by MongoDB, it does bear mentioning. BSON Type Classes ----------------- When upgrading from the legacy driver, `type classes <https://www.php.net/manual/en/mongo.types.php>`_ such as :php:`MongoId <mongoid>` must be replaced with classes in the `MongoDB\\BSON namespace <https://www.php.net/manual/en/book.bson.php>`_. The new driver also introduces interfaces for its BSON types, which should be preferred if applications need to type hint against BSON values. The following table lists all legacy classes alongside the equivalent class in the new driver. .. list-table:: :header-rows: 1 * - Legacy class - BSON type class - BSON type interface * - :php:`MongoId <mongoid>` - :php:`MongoDB\\BSON\\ObjectId <mongodb_bson_objectid>` - :php:`MongoDB\\BSON\\ObjectIdInterface <mongodb_bson_objectidinterface>` * - :php:`MongoCode <mongocode>` - :php:`MongoDB\\BSON\\Javascript <mongodb_bson_javascript>` - :php:`MongoDB\\BSON\\JavascriptInterface <mongodb_bson_javascriptinterface>` * - :php:`MongoDate <mongodate>` - :php:`MongoDB\\BSON\\UTCDateTime <mongodb_bson_utcdatetime>` - :php:`MongoDB\\BSON\\UTCDateTimeInterface <mongodb_bson_utcdatetimeinterface>` * - :php:`MongoRegex <mongoregex>` - :php:`MongoDB\\BSON\\Regex <mongodb_bson_regex>` - :php:`MongoDB\\BSON\\RegexInterface <mongodb_bson_regexinterface>` * - :php:`MongoBinData <mongobindata>` - :php:`MongoDB\\BSON\\Binary <mongodb_bson_binary>` - :php:`MongoDB\\BSON\\BinaryInterface <mongodb_bson_binaryinterface>` * - :php:`MongoInt32 <mongoint32>` - Not implemented. [1]_ - * - :php:`MongoInt64 <mongoint64>` - :php:`MongoDB\\BSON\\Int64 <mongodb_bson_int64>` - Not implemented. [2]_ * - :php:`MongoDBRef <mongodbref>` - Not implemented. [3]_ - * - :php:`MongoMinKey <mongominkey>` - :php:`MongoDB\\BSON\\MinKey <mongodb_bson_minkey>` - :php:`MongoDB\\BSON\\MinKeyInterface <mongodb_bson_minkeyinterface>` * - :php:`MongoMaxKey <mongomaxkey>` - :php:`MongoDB\\BSON\\MaxKey <mongodb_bson_maxkey>` - :php:`MongoDB\\BSON\\MaxKeyInterface <mongodb_bson_maxkeyinterface>` * - :php:`MongoTimestamp <mongotimestamp>` - :php:`MongoDB\\BSON\\Timestamp <mongodb_bson_timestamp>` - :php:`MongoDB\\BSON\\TimestampInterface <mongodb_bson_timestampinterface>` .. [1] The new driver does not implement an equivalent class for :php:`MongoInt32 <mongoint32>`. When decoding BSON, 32-bit integers will always be represented as a PHP integer. When encoding BSON, PHP integers will encode as either a 32-bit or 64-bit integer depending on their value. .. [2] :php:`MongoDB\\BSON\\Int64 <mongodb_bson_int64>` does not have an interface defined. The new driver does not allow applications to instantiate this type (i.e. its constructor is private) and it is only created during BSON decoding when a 64-bit integer cannot be represented as a PHP integer on a 32-bit platform. .. [3] The new driver does not implement an equivalent class for :php:`MongoDBRef <mongodbref>` since :manual:`DBRefs </reference/database-references>` are merely a BSON document with a particular structure and not a proper BSON type. The new driver also does not provide any helpers for working with DBRef objects, since their use is not encouraged. Collection API -------------- This library's :phpclass:`MongoDB\\Collection` class implements MongoDB's cross-driver `CRUD <https://github.com/mongodb/specifications/blob/master/source/crud/crud.rst>`_ and `Index Management <https://github.com/mongodb/specifications/blob/master/source/index-management.rst>`_ specifications. Although some method names have changed in accordance with the new specifications, the new class provides the same functionality as the legacy driver's :php:`MongoCollection <mongocollection>` class with some notable exceptions. A guiding principle in designing the new APIs was that explicit method names are preferable to overloaded terms found in the old API. For instance, :php:`MongoCollection::save() <mongocollection.save>` and :php:`MongoCollection::findAndModify() <mongocollection.findandmodify>` have different modes of operation, depending on their arguments. Methods were also split to distinguish between :manual:`updating specific fields </tutorial/modify-documents>` and :manual:`full-document replacement </tutorial/modify-documents/#replace-the-document>`. The following table lists all legacy methods alongside the equivalent method(s) in the new driver. .. list-table:: :header-rows: 1 * - :php:`MongoCollection <mongocollection>` method - :phpclass:`MongoDB\\Collection` method(s) * - :php:`MongoCollection::aggregate() <mongocollection.aggregate>` - :phpmethod:`MongoDB\\Collection::aggregate()` * - :php:`MongoCollection::aggregateCursor() <mongocollection.aggregatecursor>` - :phpmethod:`MongoDB\\Collection::aggregate()` * - :php:`MongoCollection::batchInsert() <mongocollection.batchinsert>` - :phpmethod:`MongoDB\\Collection::insertMany()` * - :php:`MongoCollection::count() <mongocollection.count>` - :phpmethod:`MongoDB\\Collection::count()` * - :php:`MongoCollection::createDBRef() <mongocollection.createdbref>` - Not yet implemented. [3]_ * - :php:`MongoCollection::createIndex() <mongocollection.createindex>` - :phpmethod:`MongoDB\\Collection::createIndex()` * - :php:`MongoCollection::deleteIndex() <mongocollection.deleteindex>` - :phpmethod:`MongoDB\\Collection::dropIndex()` * - :php:`MongoCollection::deleteIndexes() <mongocollection.deleteindexes>` - :phpmethod:`MongoDB\\Collection::dropIndexes()` * - :php:`MongoCollection::drop() <mongocollection.drop>` - :phpmethod:`MongoDB\\Collection::drop()` * - :php:`MongoCollection::distinct() <mongocollection.distinct>` - :phpmethod:`MongoDB\\Collection::distinct()` * - :php:`MongoCollection::ensureIndex() <mongocollection.ensureindex>` - :phpmethod:`MongoDB\\Collection::createIndex()` * - :php:`MongoCollection::find() <mongocollection.find>` - :phpmethod:`MongoDB\\Collection::find()` * - :php:`MongoCollection::findAndModify() <mongocollection.findandmodify>` - :phpmethod:`MongoDB\\Collection::findOneAndDelete()`, :phpmethod:`MongoDB\\Collection::findOneAndReplace()`, and :phpmethod:`MongoDB\\Collection::findOneAndUpdate()` * - :php:`MongoCollection::findOne() <mongocollection.findone>` - :phpmethod:`MongoDB\\Collection::findOne()` * - :php:`MongoCollection::getDBRef() <mongocollection.getdbref>` - Not implemented. [3]_ * - :php:`MongoCollection::getIndexInfo() <mongocollection.getindexinfo>` - :phpmethod:`MongoDB\\Collection::listIndexes()` * - :php:`MongoCollection::getName() <mongocollection.getname>` - :phpmethod:`MongoDB\\Collection::getCollectionName()` * - :php:`MongoCollection::getReadPreference() <mongocollection.getreadpreference>` - Not implemented. * - :php:`MongoCollection::getSlaveOkay() <mongocollection.getslaveokay>` - Not implemented. * - :php:`MongoCollection::getWriteConcern() <mongocollection.getwriteconcern>` - Not implemented. * - :php:`MongoCollection::group() <mongocollection.group>` - Not implemented. Use :phpmethod:`MongoDB\\Database::command()`. See `Group Command Helper`_ for an example. * - :php:`MongoCollection::insert() <mongocollection.insert>` - :phpmethod:`MongoDB\\Collection::insertOne()` * - :php:`MongoCollection::parallelCollectionScan() <mongocollection.parallelcollectionscan>` - Not implemented. * - :php:`MongoCollection::remove() <mongocollection.remove>` - :phpmethod:`MongoDB\\Collection::deleteMany()` and :phpmethod:`MongoDB\\Collection::deleteOne()` * - :php:`MongoCollection::save() <mongocollection.save>` - :phpmethod:`MongoDB\\Collection::insertOne()` or :phpmethod:`MongoDB\\Collection::replaceOne()` with the ``upsert`` option. * - :php:`MongoCollection::setReadPreference() <mongocollection.setreadpreference>` - Not implemented. Use :phpmethod:`MongoDB\\Collection::withOptions()`. * - :php:`MongoCollection::setSlaveOkay() <mongocollection.getslaveokay>` - Not implemented. * - :php:`MongoCollection::setWriteConcern() <mongocollection.setwriteconcern>` - Not implemented. Use :phpmethod:`MongoDB\\Collection::withOptions()`. * - :php:`MongoCollection::update() <mongocollection.update>` - :phpmethod:`MongoDB\\Collection::replaceOne()`, :phpmethod:`MongoDB\\Collection::updateMany()`, and :phpmethod:`MongoDB\\Collection::updateOne()`. * - :php:`MongoCollection::validate() <mongocollection.validate>` - Not implemented. Accessing IDs of Inserted Documents ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In the legacy driver, :php:`MongoCollection::insert() <mongocollection.insert>`, :php:`MongoCollection::batchInsert() <mongocollection.batchinsert>`, and :php:`MongoCollection::save() <mongocollection.save>` (when inserting) would modify their input argument by injecting an ``_id`` key with a generated ObjectId (i.e. :php:`MongoId <class.mongoid>` object). This behavior was a bit of a hack, as it did not rely on the argument being :php:`passed by reference <language.references.pass>`; instead, it directly modified memory through the extension API and could not be implemented in PHP userland. As such, it is no longer done in the new driver and library. IDs of inserted documents (whether generated or not) may be accessed through the following methods on the write result objects: - :phpmethod:`MongoDB\\InsertOneResult::getInsertedId()` for :phpmethod:`MongoDB\\Collection::insertOne()` - :phpmethod:`MongoDB\\InsertManyResult::getInsertedIds()` for :phpmethod:`MongoDB\\Collection::insertMany()` - :phpmethod:`MongoDB\\BulkWriteResult::getInsertedIds()` for :phpmethod:`MongoDB\\Collection::bulkWrite()` Bulk Write Operations ~~~~~~~~~~~~~~~~~~~~~ The legacy driver's :php:`MongoWriteBatch <class.mongowritebatch>` classes have been replaced with a general-purpose :phpmethod:`MongoDB\\Collection::bulkWrite()` method. Whereas the legacy driver only allowed bulk operations of the same type, the new method allows operations to be mixed (e.g. inserts, updates, and deletes). MongoCollection::save() Removed ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ :php:`MongoCollection::save() <mongocollection.save>`, which was syntactic sugar for an insert or upsert operation, has been removed in favor of explicitly using :phpmethod:`MongoDB\\Collection::insertOne` or :phpmethod:`MongoDB\\Collection::replaceOne` (with the ``upsert`` option). While the ``save`` method does have its uses for interactive environments, such as the ``mongo`` shell, it was intentionally excluded from the `CRUD specification <https://github.com/mongodb/specifications/blob/master/source/crud/crud.rst>`_ for language drivers. Generally, application code should know if the document has an identifier and be able to explicitly insert or replace the document and handle the returned :phpclass:`MongoDB\\InsertOneResult` or :phpclass:`MongoDB\\UpdateResult`, respectively. This also helps avoid inadvertent and potentially dangerous :manual:`full-document replacements </tutorial/modify-documents>`. Group Command Helper ~~~~~~~~~~~~~~~~~~~~ :phpclass:`MongoDB\\Collection` does have a helper method for the :manual:`group </reference/command/group>` command. The following example demonstrates how to execute a group command using the :phpmethod:`MongoDB\\Database::command()` method: .. code-block:: php <?php $database = (new MongoDB\Client)->selectDatabase('db_name'); $cursor = $database->command([ 'group' => [ 'ns' => 'collection_name', 'key' => ['field_name' => 1], 'initial' => ['total' => 0], '$reduce' => new MongoDB\BSON\Javascript('...'), ], ]); $resultDocument = $cursor->toArray()[0];