Jonathan H. Wage | OpenSky

The Doctrine Project

Who am I?Jonathan H. Wage

PHP Developer for over 10 yearsSymfony ContributorDoctrine ContributorPublished AuthorBusiness OwnerNashville, TN Resident

http://www.twitter.com/jwagehttp://www.facebook.com/jwage

I work at

What is OpenSky?“a social commerce platform”

Based in New York and is a major opensource software advocate

http://www.shopopensky.com

OpenSky TechnologiesPHP 5.3.2Apache2Symfony2Doctrine2jQuerymule, stomp, hornetqMongoDBnginxvarnish

What is Doctrine?- Open Source PHP Project started in

2006- Specializes in database functionality

- Database Abstraction Layer (DBAL)- Database Migrations- Object Relational Mapper (DBAL)- MongoDB Object Document Manager (ODM)- CouchDB Object Document Manager (ODM)

Who is on the team?

• Roman S. Borschel

• Guilherme Blanco

• Benjamin Eberlei

• Bulat Shakirzyanov

• Jonathan H. Wage

Project History- First commit April 13th 2006

- First stable version finished and Released September 1st 2008

- One of the first ORM implementations for PHP

- 1.0 is First LTS(long term support) release. Maintained until March 1st 2010

- Integrated with many popular frameworks: Symfony, Zend Framework, Code Igniter

Doctrine Libraries- Database Abstraction Layer

- Database Migrations

- Object Relational Mapper

- MongoDB Object Document Manager

- CouchDB Object Document Manager

DBALDatabase Abstraction Layer

Database Abstraction LayerThe Doctrine Database AbstractionLayer (DBAL) is a thin layer on top ofPDO, it offers:

- select, update, delete, transactions

- database schema introspection

- schema management

Can be used standalone

Evolved fork of PEAR MDB, MDB2, Zend_Db, etc.

DownloadYou can download a standalonepackage to get started using the DBAL:

http://www.doctrine-project.org/projects/dbal/download

AutoloaderTo use any Doctrine library you mustregister an autoloader:

use Doctrine\Common\ClassLoader;

require '/path/to/doctrine-common/lib/Doctrine/Common/ClassLoader.php';

$classLoader = new ClassLoader('Doctrine\DBAL', '/path/to/doctrine-dbal/lib');$classLoader->register();

Create a Connection

$config = new \Doctrine\DBAL\Configuration();//..$connectionParams = array( 'dbname' => 'mydb', 'user' => 'user', 'password' => 'secret', 'host' => 'localhost', 'driver' => 'pdo_mysql',);$conn = DriverManager::getConnection($connectionParams);

Data APIprepare($sql) - Prepare a given sql statement and return the \Doctrine\DBAL\Driver

\Statement instance.executeUpdate($sql, array $params) - Executes a prepared statement with the given sql

and parameters and returns the affected rows count.execute($sql, array $params) - Creates a prepared statement for the given sql and passes

the parameters to the execute method, then returning the statement.fetchAll($sql, array $params) - Execute the query and fetch all results into an array.fetchArray($sql, array $params) - Numeric index retrieval of first result row of the given

query.fetchBoth($sql, array $params) - Both numeric and assoc column name retrieval of the first

result row.fetchColumn($sql, array $params, $colnum) - Retrieve only the given column of the first

result row.fetchRow($sql, array $params) - Retrieve assoc row of the first result row.select($sql, $limit, $offset) - Modify the given query with a limit clause.delete($tableName, array $identifier) - Delete all rows of a table matching the given

identifier, where keys are column names.insert($tableName, array $data) - Insert a row into the given table name using the key

value pairs of data.

Very Similar to PDO

$users = $conn->fetchAll('SELECT * FROM users');

Schema ManagerLearn about and modify your databasethrough the SchemaManager:

$sm = $conn->getSchemaManager();

Introspection APIlistDatabases()listFunctions()listSequences()listTableColumns($tableName)listTableConstraints($tableName)listTableDetails($tableName)listTableForeignKeys($tableName)listTableIndexes($tableName)listTables()

Introspection API

$tables = $sm->listTables();foreach ($tables as $table) { $columns = $sm->listTableColumns($table); // ...}

DDL StatementsProgromatically issue DDL statements:

$columns = array( 'id' => array( 'type' => \Doctrine\DBAL\Type::getType('integer'), 'autoincrement' => true, 'primary' => true, 'notnull' => true ), 'test' => array( 'type' => \Doctrine\DBAL\Type::getType('string'), 'length' => 255 ));

$options = array();

$sm->createTable('new_table', $columns, $options);

DDL StatementsProgromatically issue DDL statements:

$definition = array( 'name' => 'user_id_fk', 'local' => 'user_id', 'foreign' => 'id', 'foreignTable' => 'user');$sm->createForeignKey('profile', $definition);

Try a MethodYou can try a method and return true ifthe operation was successful:

if ($sm->tryMethod('createTable', 'new_table', $columns, $options)) { // do something}

Drop and Create Database

try { $sm->dropDatabase('test_db');} catch (Exception $e) {}

$sm->createDatabase('test_db');

Drop and Create DatabaseA little better! Every drop and createfunctionality in the API has a methodthat follows the dropAndCreate pattern:

$sm->dropAndCreateDatabase('test_db');

Schema Representation

$platform = $em->getConnection()->getDatabasePlatform();

$schema = new \Doctrine\DBAL\Schema\Schema();$myTable = $schema->createTable("my_table");$myTable->addColumn("id", "integer", array("unsigned" => true));$myTable->addColumn("username", "string", array("length" => 32));$myTable->setPrimaryKey(array("id"));

// get queries to create this schema.$queries = $schema->toSql($platform);

Array( [0] => CREATE TABLE my_table (id INTEGER NOT NULL, username VARCHAR(32) NOT NULL, PRIMARY KEY("id")))

Schema Representation

Array( [0] => DROP TABLE my_table)

Returns the reverse SQL of what toSql() returns

// ......

// get queries to safely delete this schema.$dropSchema = $schema->toDropSql($platform);

Array( [0] => DROP TABLE my_table)

Comparing Schemas$fromSchema = new \Doctrine\DBAL\Schema\Schema();$myTable = $fromSchema->createTable("my_table");$myTable->addColumn("id", "integer", array("unsigned" => true));$myTable->addColumn("username", "string", array("length" => 32));$myTable->setPrimaryKey(array("id"));

$toSchema = new \Doctrine\DBAL\Schema\Schema();$myTable = $toSchema->createTable("my_table");$myTable->addColumn("id", "integer", array("unsigned" => true));$myTable->addColumn("username", "string", array("length" => 32));$myTable->addColumn("email", "string", array("length" => 255));$myTable->setPrimaryKey(array("id"));

$comparator = new \Doctrine\DBAL\Schema\Comparator();$schemaDiff = $comparator->compare($fromSchema, $toSchema);

// queries to get from one to another schema.$queries = $schemaDiff->toSql($platform);

print_r($queries);

ALTER TABLE my_table ADD email VARCHAR(255) NOT NULL

ORMObject Relational Mapper

What is ORM?“Technique for converting data between incompatible type systems in object-oriented programming languages.”

http://en.wikipedia.org/wiki/Object-relational_mapping

The ORM is built on top of Common and DBAL

ORM Goals- Maintain transparency

- Keep domain and persistence layer separated

- Performance

- Consistent and decoupled API

- Well defined semantics

http://www.doctrine-project.org/projects/orm/download

Download

ArchitectureEntities - Lightweight persistent domain object - Regular PHP class - Does not extend any base Doctrine class - Cannot be final or contain final methods - Any two entities in a hierarchy of classes must not have

a mapped property with the same name - Supports inheritance, polymorphic associations and

polymorphic queries. - Both abstract and concrete classes can be entities - Entities may extend non-entity classes as well as entity

classes, and non-entity classes may extend entity classes

Architecture- No more base class required

- Values stored in object properties

- Persistence is done transparentlynamespace Entities;

class User{ private $id; private $name;}

ArchitectureThe EntityManager - Central access point to the ORM functionality provided by

Doctrine 2. API is used to manage the persistence of your objects and to query for persistent objects.

- Employes transactional write behind strategy that delays the execution of SQL statements in order to execute them in the most efficient way

- Execute at end of transaction so that all write locks are quickly releases

- Internally an EntityManager uses a UnitOfWork to keep track of your objects

Create EntityManagerCreate a new EntityManager instance:

$config = new \Doctrine\ORM\Configuration();$config->setMetadataCacheImpl(new \Doctrine\Common\Cache\ArrayCache);$driverImpl = $config->newDefaultAnnotationDriver(array(__DIR__."/Entities"));$config->setMetadataDriverImpl($driverImpl);

$config->setProxyDir(__DIR__ . '/Proxies');$config->setProxyNamespace('Proxies');

$em = \Doctrine\ORM\EntityManager::create($conn, $config);

Map entities to RDBMS tablesEntities are just regular PHP objects

namespace Entities;

class User{ private $id; private $name;}

Map entities to RDBMS tablesEntities are just regular PHP objects

Mapped By:- Annotations

namespace Entities;

/** * @Entity @Table(name="users") */class User{ /** @Id @Column(type="integer") @GeneratedValue */ private $id;

/** @Column(length=50) */ private $name;}

Map entities to RDBMS tablesEntities are just regular PHP objects:

Mapped By:- Annotations- YAML

Entities\User: type: entity table: users id: id: type: integer generator: strategy: AUTO fields: name: type: string length: 255

Map entities to RDBMS tablesEntities are just regular PHP objects:

Mapped By:- Annotations- YAML- XML

<?xml version="1.0" encoding="UTF-8"?><doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">

<entity name="Entities\User" table="users"> <id name="id" type="integer"> <generator strategy="AUTO"/> </id> <field name="name" type="string" length="50"/> </entity>

</doctrine-mapping>

Mapping Performance- Only parsed once

- Cached using configured cache driver

- Subsequent requests pull mapping information from configured cache driver

Working with ObjectsUse the $em to manage the persistenceof your entities:

$user = new User;$user->setName('Jonathan H. Wage');

$em->persist($user);$em->flush();

Working with ObjectsUpdating an object:

$user = $em->getRepository('User') ->find(array('name' => 'jwage'));

// modify the already managed object$user->setPassword('changed');$em->flush(); // issues update

Working with ObjectsRemoving an object:

$user = $em->getRepository('User') ->find(array('name' => 'jwage'));

// schedule for deletion$em->remove($user);$em->flush(); // issues delete

TransactionsImplicit:

EntityManager#flush() will begin and commit/rollback a transaction

$user = new User;$user->setName('George');$em->persist($user);$em->flush();

TransactionsExplicit:

// $em instanceof EntityManager$em->getConnection()->beginTransaction(); // suspend auto-committry { //... do some work $user = new User; $user->setName('George'); $em->persist($user); $em->flush(); $em->getConnection()->commit();} catch (Exception $e) { $em->getConnection()->rollback(); $em->close(); throw $e;}

TransactionsA more convenient explicit transaction:

// $em instanceof EntityManager$em->transactional(function($em) { //... do some work $user = new User; $user->setName('George'); $em->persist($user);});

Transactions and Performance

for ($i = 0; $i < 20; ++$i) { $user = new User; $user->name = 'Jonathan H. Wage'; $em->persist($user);}

$s = microtime(true);$em->flush();$e = microtime(true);echo $e - $s;

Transactions and PerformanceHow you use transactions can greatlyaffect performance. Here is the samething using raw PHP code:

$s = microtime(true);for ($i = 0; $i < 20; ++$i) { mysql_query("INSERT INTO users (name) VALUES ('Jonathan H. Wage')", $link);}$e = microtime(true);echo $e - $s;

Which is faster?- The one using no ORM, and no

abstraction at all?

- Or the one using the Doctrine ORM?

Which is faster?- The one using no ORM, and no

abstraction at all?

- Or the one using the Doctrine ORM?

- Doctrine2 wins! How?

Doctrine2 0.0094 seconds

mysql_query 0.0165 seconds

Not FasterDoctrine just automatically performed the inserts inside one transaction. Here is the code updated to use transactions:

$s = microtime(true);mysql_query('START TRANSACTION', $link);for ($i = 0; $i < 20; ++$i) { mysql_query("INSERT INTO users (name) VALUES ('Jonathan H. Wage')", $link);}mysql_query('COMMIT', $link);$e = microtime(true);echo $e - $s;

Much FasterTransactions matter and can affectperformance greater than any codeoptimization!

Doctrine2 0.0094 seconds

mysql_query 0.0165 seconds0.0028

Locking SupportOptimistic locking with integer:

class User{ // ... /** @Version @Column(type="integer") */ private $version; // ...}

Locking SupportOptimistic locking with timestamp:

class User{ // ... /** @Version @Column(type="datetime") */ private $version; // ...}

Locking SupportVerify version when finding:

use Doctrine\DBAL\LockMode;use Doctrine\ORM\OptimisticLockException;

$theEntityId = 1;$expectedVersion = 184;

try { $entity = $em->find('User', $theEntityId, LockMode::OPTIMISTIC, $expectedVersion);

// do the work

$em->flush();} catch(OptimisticLockException $e) { echo "Sorry, but someone else has already changed this entity. Please apply the changes again!";}

Locking SupportExample implementation:

$post = $em->find('BlogPost', 123456);

echo '<input type="hidden" name="id" value="' . $post->getId() . '" />';echo '<input type="hidden" name="version" value="' . $post->getCurrentVersion() . '" />';

$postId = (int) $_GET['id'];$postVersion = (int) $_GET['version'];

$post = $em->find('BlogPost', $postId, \Doctrine\DBAL\LockMode::OPTIMISTIC, $postVersion);

DQLDoctrine Query Language

DQL - DQL stands for Doctrine Query Language and is an

Object Query Language derivate that is very similar to the Hibernate Query Language (HQL) or the Java Persistence Query Language (JPQL).

- DQL provides powerful querying capabilities over your object model. Imagine all your objects lying around in some storage (like an object database). When writing DQL queries, think about querying that storage to find a certain subset of your objects.

DQL Parser- Parser completely re-written from

scratch

- Parsed by top down recursive descent lexer parser that constructs an AST(Abstract Syntax Tree)

- Platform specific SQL is generated from AST

Doctrine Query Language

$q = $em->createQuery('SELECT u FROM User u');$users = $q->execute();

Query BuilderSame query built using the QueryBuilder

$qb = $em->createQueryBuilder() ->select('u') ->from('User', 'u');

$q = $qb->getQuery();$users = $q->execute();

More Examples$query = $em->createQuery( 'SELECT u, g, FROM User u ' . 'LEFT JOIN u.Groups g ' . 'ORDER BY u.name ASC, g.name ASC');$users = $query->execute();

$qb = $em->createQueryBuilder() ->select('u, g') ->from('User', 'u') ->leftJoin('u.Groups', 'g') ->orderBy('u.name', 'ASC') ->addOrderBy('g.name', 'ASC');

$query = $qb->getQuery();

Executing QueriesExecuting and getting results

$users = $query->execute();

foreach ($users as $user) { // ... foreach ($user->getGroups() as $group) { // ... }}

Executing QueriesExecute query and iterate over resultskeeping memory usage low:

foreach ($query->iterate() as $user) { // ... foreach ($user->getGroups() as $group) { // ... }}

Result CacheOptionally cache the results of your queries in your driver of choice:

$cacheDriver = new \Doctrine\Common\Cache\ApcCache();$config->setResultCacheImpl($cacheDriver);

$query = $em->createQuery('select u from Entities\User u');$query->useResultCache(true, 3600, 'my_query_name');

$users = $query->execute();

$users = $query->execute(); // 2nd time pulls from cache

InheritanceDoctrine supports mapping entities thatuse inheritance with the followingstrategies:

- Mapped Superclass- Single Table Inheritance- Class Table Inheritance

Mapped Superclasses/** @MappedSuperclass */abstract class MappedSuperclassBase{ /** @Column(type="integer") */ private $mapped1; /** @Column(type="string") */ private $mapped2; /** * @OneToOne(targetEntity="MappedSuperclassRelated1") * @JoinColumn(name="related1_id", referencedColumnName="id") */ private $mappedRelated1;

// ... more fields and methods}

/** @Entity */class EntitySubClass extends MappedSuperclassBase{ /** @Id @Column(type="integer") */ private $id; /** @Column(type="string") */ private $name;

// ... more fields and methods}

Single Table Inheritance

/** * @Entity * @InheritanceType("SINGLE_TABLE") * @DiscriminatorColumn(name="discr", type="string") * @DiscriminatorMap({"person" = "Person", "employee" = "Employee"}) */class Person{ // ...}

/** * @Entity */class Employee extends Person{ // ...}

Single Table Inheritance- All entities share one table.

- To distinguish which row represents which type in the hierarchy a so-called discriminator column is used.

Class Table Inheritance

/** * @Entity * @InheritanceType("JOINED") * @DiscriminatorColumn(name="discr", type="string") * @DiscriminatorMap({"person" = "Person", "employee" = "Employee"}) */class Person{ // ...}

/** @Entity */class Employee extends Person{ // ...}

Class Table Inheritance- Each class in a hierarchy is mapped to several

tables: its own table and the tables of all parent classes.

- The table of a child class is linked to the table of a parent class through a foreign key constraint.

- A discriminator column is used in the topmost table of the hierarchy because this is the easiest way to achieve polymorphic queries.

Bulk Inserts with DomainInsert 10000 objects batches of 20:

$batchSize = 20;for ($i = 1; $i <= 10000; ++$i) { $user = new User; $user->setStatus('user'); $user->setUsername('user' . $i); $user->setName('Mr.Smith-' . $i); $em->persist($user); if ($i % $batchSize == 0) { $em->flush(); $em->clear(); // Detaches all objects from Doctrine! }}

Bulk Update with DQL

$q = $em->createQuery('update Manager m set m.salary = m.salary * 0.9');$numUpdated = $q->execute();

Bulk Update with DomainUpdate objects in batches of 20:

$batchSize = 20;$i = 0;$q = $em->createQuery('select u from User u');$iterableResult = $q->iterate();foreach($iterableResult AS $row) { $user = $row[0]; $user->increaseCredit(); $user->calculateNewBonuses(); if (($i % $batchSize) == 0) { $em->flush(); // Executes all updates. $em->clear(); // Detaches all objects from Doctrine! } ++$i;}

Bulk Delete with DQL

$q = $em->createQuery('delete from Manager m where m.salary > 100000');$numDeleted = $q->execute();

Bulk Delete with Domain

$batchSize = 20;$i = 0;$q = $em->createQuery('select u from User u');$iterableResult = $q->iterate();while (($row = $iterableResult->next()) !== false) { $em->remove($row[0]); if (($i % $batchSize) == 0) { $em->flush(); // Executes all deletions. $em->clear(); // Detaches all objects from Doctrine! } ++$i;}

EventsDoctrine triggers events throughout thelifecycle of objects it manages:

- preRemove- postRemove- prePersist- postPersist- preUpdate- postUpdate- preLoad- postLoad

Example

/** * @Entity * @HasLifecycleCallbacks */class BlogPost{ // ...

/** @PreUpdate */ public function prePersist() { $this->createdAt = new DateTime(); }

/** @PreUpdate */ public function preUpdate() { $this->updatedAt = new DateTime(); }}

Using Raw SQL- Write a raw SQL string

- Map the result set of the SQL query using a ResultSetMapping instance

Using Raw SQL

$sql = 'SELECT id, name FROM users WHERE username = ?';

$rsm = new ResultSetMapping;$rsm->addEntityResult('User', 'u');$rsm->addFieldResult('u', 'id', 'id');$rsm->addFieldResult('u', 'name', 'name');

$query = $this->_em->createNativeQuery($sql, $rsm);$query->setParameter(1, 'jwage');

$users = $query->getResult();

Why use an object mapper?

Encapsulate your domain in an object oriented interface

Encapsulation

The organization of your domain logic in an OO way improved maintainability

Maintainability

Keeping a clean OO domain model makes your business logic easily testable for improved stability

Testability

Write portable and thin application controller code and fat models.

Portability

Questions?

- http://www.twitter.com/jwage- http://www.facebook.com/jwage- http://www.jwage.com

OpenSky is hiring! Inquire via e-mail at jwage@theopenskyproject.com or in person after this presentation!