1.
Enterprise Database Design Patterns in PHP Hugo Hamon – OSIDays 2011

2.
By Martin Fowler§ Table Module§ Transaction Script§ Row Data Gateway§ Table Data Gateway§ Active Record§ Data Mapper§ Unit of Work§ Identity Map§ Data Transfer Object§ …

3.
Table Data Gateway

4.
« An object that acts as a Gateway toa database table. One instancehandles all the rows in the table. » Martin Fowler

5.
Same asData Access Object Martin Fowler

6.
CRUD

7.
$table = new OrderGateway(new Connection(...));$table->insert(XX123456789, 358.80, unpaid);$table->update(42, XX123456789, 358.80, paid);$table->delete(42);

8.
class OrderGateway{ private $conn; public function __construct(Connection $conn) { $this->conn = $conn; }}

9.
class OrderGateway{ public function insert($reference, $amount, $status) { $query = INSERT INTO orders (reference, amount,status) VALUES (?, ?, ?); $data = array($reference, $amount, $status); $this->conn->executeQuery($query, $data); return $this->conn->lastInsertId(); }}

10.
class OrderGateway{ public function update($pk, $ref, $amount, $status) { $query = UPDATE orders SET reference = ?, amount= ?, status = ? WHERE id = ?; $data = array($ref, $amount, $status, $pk); return $this->conn->executeQuery($query, $data); }}

11.
class OrderGateway{ public function delete($pk) { return $this->conn->executeQuery( DELETE FROM orders WHERE id = ?, array($pk) ); }}

12.
Finders

13.
$orders = $table->findAll();$orders = $table->findPaidOrders();$orders = $table->findUnpaidOrders();$orders = $table->findBy(array( status => paid, amount => 250.00));$order = $table->find(42);$order = $table->findOneBy(array(reference => ...));

14.
class OrderGateway{ public function findAll() { $query = SELECT * FROM orders; return $this->conn->fetchAll($query); } public function find($pk) { $rs = $this->conn->findBy(array(id => $pk)); return 1 === count($rs) ? $rs[0] : false; }}

15.
public function findBy(array $criteria){ $where = array(); foreach ($criteria as $field => $value) { $where[] = sprintf(%s = ?); } $q = sprintf( SELECT * FROM orders WHERE %s, implode( AND , $where) ); return $this->conn->fetchAll($q, array_values($criteria));}

16.
public function findPaidOrders(){ return $this->findBy(array(status => paid));}public function findUnpaidOrders(){ return $this->findBy(array(status => unpaid));}

17.
When to use it?

18.
Row Data Gateway

19.
« An object that acts as a Gateway toa single record in a data source. Thereis one instance per row. » Martin Fowler

20.
CRUD

21.
class Order{ private $id; private $reference; private $amount; private $vat; private $total; private $createdAt; // Getters and setters for each property // ...}

22.
$conn = new Connection(...);$order = new OrderGateway();$order->setReference(XX12345678);$order->setAmount(300.00);$order->setVat(58.80);$order->setTotal(358.80);$order->setCreatedAt(new DateTime());$order->insert($conn);

23.
class OrderGateway{ public function insert(Connection $conn) { $query = INSERT INTO orders (reference, amount, vat,total, created_at) VALUES (?, ?, ?, ?, ?); $data = array( $this->reference, $this->amount, $this->vat, $this->total, $this->createdAt->format(Y-m-d H:i:s) ); $conn->executeQuery($query, $data); $this->id = $conn->lastInsertId(); }}

24.
Finders

25.
OrderFinder::setConnection($conn);$order = OrderFinder::findByReference(XX12345678);echo sprintf(%01.2f euros, $order->getTotal());

26.
class OrderFinder{ static public function findByReference($reference) { $query = SELECT * FROM orders WHERE reference = ?; $rs = static::getConnection() ->fetchSingle($query, array($reference)) ; return $rs ? OrderGateway::load($rs) : false; }}

27.
class OrderGateway{ static public function load(array $rs) { $order = new OrderGateway($rs[id]); $order->setReference($rs[reference]); $order->setAmount($rs[amount]); $order->setVat($rs[vat]); $order->setTotal($rs[total]); $order->setCreatedAt(new DateTime($rs[created_at])); return $order; }}

28.
OrderFinder::setConnection($conn);$orders = OrderFinder::findMostExpensiveOrders(10);foreach ($orders as $order) { echo $order->getReference(), "n"; echo sprintf(%01.2f euros, $order->getTotal()), "n"; echo "n-----n";}

29.
class OrderFinder{ static public function findMostExpensiveOrders($limit) { $orders = array(); $query = SELECT * FROM orders ORDER BY total DESC LIMIT ?; $rs = static::getConnection()->fetchAll($query, array($limit)); foreach ($rs as $data) { $orders[] = OrderGateway::load($data); } return $orders; }}

30.
When to use it?

31.
Active Record

32.
« An object that wraps a row in adatabase table or view, encapsulatesthe database access, and addsdomain logic on that data. » Martin Fowler

33.
Active Record =Row Data Gateway + Business Logic

34.
Active Record =Data + Behaviors

35.
Active Record =Properties + Methods

36.
class Order{ private $id; private $reference; private $amount; private $vat; private $vatRate; private $total; private $createdAt; private $status; private $isPaid; // Getters and setters for each property // ...}

37.
class Order{ public function __construct($id = null) { if (null !== $id) { $this->id = $id; } $this->vatRate = 0.00; $this->vat = 0.00; $this->amount = 0.00; $this->total = 0.00; $this->isPaid = false; $this->status = processing; $this->createdAt = new DateTime(); }}

38.
$conn = new Connection(...);$order = new Order();$order->setReference(XX12345678);$order->setAmount(300.00);$order->setVatRate(0.196);$order->applyDiscount(20.00);$order->updateTotal();$order->save($conn);

39.
class Order{ public function applyDiscount($discount) { $this->amount -= $discount; } public function updateTotal() { if ($this->vatRate) { $this->vat = $this->amount * $this->vatRate; } $this->total = $this->amount + $this->vat; }}

40.
class Order{ public function isPaid() { return $this->isPaid; } public function setPaid() { $this->isPaid = true; }}

41.
class Order{ public function isReadyForShipment() { return $this->isPaid() && complete == $this->status; } public function ship($address) { $this->doShipment($address); $this->status = shipped; }}

42.
class OrderController{ public function confirmAction($reference) { $conn = $this->getDatabaseConnection(); $order = ...; $order->setPaid(); $order->save($conn); if ($order->isReadyForShipment()) { $order->ship(); return $this->view->render(ship.php, array(order => $order)); } return $this->view->render(pending.php, array(order => $order)); }}

43.
Refactoring

44.
abstract class ActiveRecord{ protected $fields = array(); abstract public function getTableName(); public function save(Connection $conn) { // insert or update $fields in the database } public function delete(Connection $conn) { // delete the object from the database }}

45.
class Order extends ActiveRecord{ private $amount; abstract public function getTableName() { return tbl_orders; } public function setAmount($amount) { $this->amount = $amount; $this->fields[amount] = $amount; }}

46.
When to use it?

47.
Data Mapper

48.
« A layer of Mappers that moves databetween objects and a databasewhile keeping them independent ofeach other and the mapper itself. » Martin Fowler

49.
« Man in the Middle »

50.
http://martinfowler.com

51.
class OrderMapper{ private $conn; public function __construct(Connection $conn) { $this->conn = $conn; } public function store(Order $order) { // Execute the query to persist the object to the DB } public function remove(Order $order) { // Executes the query to remove the object to the DB }}

52.
$order = new Order();$order->setReference(XX12345678);$order->setAmount(300.00);$order->setVatRate(0.196);$order->updateTotal();$conn = new Connection(mysql:host=localhost ...);$mapper = new OrderMapper($conn);$mapper->store($order);

53.
class OrderMapper{ public function findAll() { $objects = array(); $query = SELECT id, reference, vat ... FROM orders; foreach ($this->conn->fetchAll($query) as $data) { $object = new Order($data[id]); $object->load($data); $objects[] = $object; } return $objects; }}

54.
class OrderMapper{ public function find($pk) { $query = SELECT id, vat ... FROM orders WHERE id = ?; $object = false; if (false !== $data = conn->fetch($query, array($pk))) { $object = new Order($data[id]); $object->load($data); } return $object; }}

55.
$conn = new Connection(mysql:host=localhost ...);$mapper = new OrderMapper($conn);$order = $mapper->find(42);$order->setAmount(399.00);$order->updateTotal();$mapper->store($order);

56.
Unit testing

57.
class OrderTest extends PHPUnit_Framework_TestCase{ public function testUpdateTotal() { $order = new Order(); $order->setAmount(299.00); $order->setVatRate(0.196); $order->updateTotal(); $this->assertEquals(58.60, $order->getVat()); $this->assertEquals(357.60, $order->getTotal()); }}

58.
When to use it?

59.
IdentityMap

60.
« Ensures that each object getsloaded only once by keeping everyloaded object in a map. » Martin Fowler

61.
$conn = new Connection(mysql:host=localhost ...);$mapper = new OrderMapper($conn);$orderA = $mapper->find(42);$orderB = $mapper->find(42);$orderC = $mapper->find(42);// 3 SQL queries for getting the same object

62.
The solution

63.
class IdentityMap implements IdentityMapInterface{ private $entities; public function fetch($class, $pk) { $key = $this->getKey($class, $pk); if (isset($this->entities[$key])) { return $this->entities[$key]; } return false; }}

64.
class IdentityMap implements IdentityMapInterface{ public function store(ValueObjectInterface $entity) { $key = $this->getKey($class, $entity->getId()); $this->entities[$key] = $entity; } private function getKey($class, $pk) { return $class.-.$pk; }}

65.
class Order implements ValueObjectInterface{ private $id; private $reference; private $amount; // ... public function getId() { return $this->id; }}

66.
class OrderMapper extends DatabaseMapper{ private $map; public function __construct(IdentityMap $map, ...) { parent::__construct($conn); $this->map = $map; }}

67.
class OrderMapper extends DatabaseMapper{ public function store(Order $order) { parent::store($order); $this->map->store(Order, $object); }}

68.
class OrderMapper extends DatabaseMapper{ public function find($pk) { if (false !== $object = $this->map->fetch($pk)) { return $object; } if (false !== $object = parent::find($pk)) { $this->map->store(Order, $object); } return $object; }}

69.
$conn = new Connection(mysql:host=localhost ...);$mapper = new OrderMapper(new IdentityMap(), $conn);$orderA = $mapper->find(42); // Query$orderB = $mapper->find(42); // No query$orderB->setAmount(299.00);$orderB->setVatRate(0.196);$orderB->updateTotal();$mapper->store($orderB);$orderC = $mapper->find(42); // No query

70.
Query Object

71.
$query = Query::create() ->select(array(id, reference, amount, status)) ->from(orders) ->where(Criteria::equals(status, paid)) ->where(Criteria::greaterThan(amount, 2000)) ->where(Criteria::like(reference, XX123%)) ->orderBy(amount, desc) ->getSql();// SELECT id, reference, amount, status// WHERE status = ? AND amount > ? AND reference LIKE ?// ORDER BY amount DESC

72.
class Criteria{ private $field; private $operator; private $parameters; public function __construct($field, $operator, $value) { $this->field = $field; $this->operator = $operator; $this->parameters[] = $value; }}

73.
class Criteria{ static public function equal($field, $value, $vars) { return new Criteria($field, =, $vars); } static public function notEqual($field, $value, $vars) { return new Criteria($field, <>, $vars); }}

74.
Custom Queries

75.
class OrderQuery extends Query{ public function filterByPriority($amount) { return $this ->where(Criteria::equal(status, paid)) ->where(Criteria::greaterThan(amount, $amount)) ; } public function filterByReference($like) { return $this->where(Criteria::like(reference, $like)); }}

76.
$query = OrderQuery::create() ->filterByPriority(2000) ->filterByReference(%567%) ->orderByAmount(DESC) ->getSql();

77.
ORM Tools

78.
Zend_DB Propel Doctrine 2.xPomm Doctrine 1.2

79.
QuizzCan you guess the patterns?

80.
$table = new Author();// New empty row$row = $table->createRow();// Insert a new row$row->firstName = Jules;$row->lastName = Verne;$row->save();

81.
$pax1 = new Passenger(Hugo Hamon, 7B);$pax2 = new Passenger(John Smith, 3A);$aircraft = new Plane();$aircraft->setCapacity(120);$aircraft->addPassenger($pax1);$aircraft->addPassenger($pax2);$aircraft->save();$pax2->changeSeat(2C);$pax2->save();$aircraft->isAvailableSeat(3A) ? Yes : No;

82.
$post = new BlogPost();$post->setTitle(My First Blog Post);$post->setBody(Some content...);$author = new Author();$author->setName(Hugo Hamon);$author->addPost($post);$em->persist($user);$em->persist($post);$em->flush();

83.
$data = array( first_name => Jules, last_name => Vernes,);$table = new AuthorTable();$table->insert($data);

84.
Conclusion

85.
By Martin Fowler§ Table Module§ Transaction Script§ Row Data Gateway§ Table Data Gateway§ Active Record§ Data Mapper§ Unit of Work§ Identity Map§ Data Transfer Object§ …

86.
Ques&ons? 92-98, boulevard Victor Hugo 92 115 Clichy Cedex trainings@sensio.com (+33 (0)1 40 99 82 11) sensiolabs.com - symfony.com – trainings.sensiolabs.com