You're modeling it wrong

Transcript

1. You're modeling it wrong

2. Marijn Huizendveld

3. @marijn

4. @huizendveld

5. Your tickets, our concern.

6. Command Query Responsibility Segregation

7. Command Query Responsibility Segregation

8. CQRS? Did you mean cars? cqrs

9. Relevantie: Complexe applicaties

10. •Waardevolle data •Continue onderhevig aan andere vereisten •Schaalbaarheid is belangrijk

    Dat wil zeggen:

11. Applicaties die direct bijdragen aan het concurrentievoordeel van de organisatie

12. Wie van jullie werkt momenteel aan een complexe applicatie?

13. Huidige situatie

14. None

15. RDBMS

16. NoSQL

17. CREATE READ UPDATE DELETE

18. CREATE

19. POST /products

20. INSERT INTO product (name, version) VALUES (“iPhone”, 5)

21. READ

22. GET /products/iphone

23. SELECT * FROM product WHERE name = “iPhone” AND version

    > 4

24. UPDATE

25. PATCH /products/iphone

26. UPDATE product SET available = 0 WHERE version < 4

27. DELETE

28. DELETE /products/iphone

29. DELETE product WHERE version < 4

30. OOP I

31. OOP

32. OOP WE

33. <?php final class Product { private $id; private $name; public

    function __construct($name) { $this->name = $name; } public function getId() { return $this->id; } public function getName() { return $this->id; } }

34. Enter ORM

35. <?php $iPhone = new Product('iPhone'); $entityManager->persist($iPhone); $entityManager->flush();

36. INSERT INTO product VALUES (“iPhone”)

37. Awesome?

38. Voor een blog app?

39. Ja!

40. Voor complexe applicaties?

41. Nee!

42. We're modeling this wrong

43. Problemen •Betekenisarm model •Niet intuïtief voor de gebruiker •Het model

    is beperkt en niet contextueel •Complexe queries zijn moeilijk •Waardevolle data gaat continue verloren

44. En nu?

45. Command Query Responsibility Segregation

46. Je kunt er vandaag nog mee beginnen...

47. Echt waar Mike?

48. Stap 1: Splits je universele model in twee modellen

49. Een read-model

50. <?php class CustomerReadModel { private $id; private $name; private $address;

    private $gender; public function getName() { return $this->name; } public function getAddress() { return $this->address; } public function getGender() { return $this->gender; } }

51. Een write-model

52. <?php class Customer { private $id; private $name; private $address;

    private $gender; public function setName($name) { $this->name = $name; } public function setAddress(Address $address) { $this->address = $address; } public function setGender($gender) { $this->gender = $gender; } }

53. So what?

54. Je kunt ze nu onafhankelijk inrichten

55. Je kunt ze onafhankelijk schalen

56. Stap 2: Geef de methoden van je write- model betekenis

57. <?php class Customer { private $id; private $name; private $address;

    private $gender; public function __construct($name, $gender, $address) { $this->name = $name; $this->gender = $gender; $this->address = $address; } public function moveToNewLivingAddress(Address $newAddress) { $this->address = $newAddress; } }

58. So what?

59. Nu is het duidelijk welke gegevens samen gewijzigd mogen worden

60. Je kunt nu formulieren maken voor alleen die wijzigingen

61. Stap 3: Ontwikkel specifieke read-models

62. <?php /** * Publications are the contextual point for all

    other objects * * @author Marijn Huizendveld <[email protected]> * @version $Revision: 163 $ changed by $Author: buroknapzak $ * * @copyright De Baas Media (2010) */ class kluPublicationPeer extends BasekluPublicationPeer { /** * Select the publications that have recently been updated. * * @param string $arg_connection * * @return array */ static public function retrieveRecentlyUpdatedForDomain ($arg_domainUnifiedResourceName = NULL, $arg_connection = NULL) { $sql = "SELECT * FROM (SELECT `publications`.`id` AS ID " . ", `publications`.`name` AS NAME " . ", `publications`.`unified_resource_name` AS UNIFIED_RESOURCE_NAME " . ", `publications`.`domain_unified_resource_name` AS DOMAIN_UNIFIED_RESOURCE_NAME " . ", `publications`.`introduction` AS INTRODUCTION " . ", `publications`.`created_at` AS CREATED_AT " . ", MAX(`revision_requests`.`applied_at`) AS UPDATED_AT " . ", `publications`.`deleted_at` AS DELETED_AT " . "FROM `revision_requests` " . "LEFT JOIN `updates` " . "ON (`updates`.`id` = `revision_requests`.`update_id`) " . "LEFT JOIN `update_collections` " . "ON `updates`.`collection_unified_resource_name` = `update_collections`.`unified_resource_name` " . "LEFT JOIN `publications` " . "ON (`publications`.`id` = `revision_requests`.`publication_id`) " . "WHERE `updates`.`revision_request_id` IS NULL " . "AND `publications`.`deleted_at` IS NULL " . "AND `publications`.`domain_unified_resource_name` = ? " . "AND `update_collections`.`publish_at` <= NOW() " . "AND `update_collections`.`publish_until` > NOW() " . "GROUP BY `revision_requests`.`publication_id` " . "ORDER BY `updated_at` DESC) " . "`publications` ORDER BY `updated_at` DESC"; $connection = NULL === $arg_connection ? Propel::getConnection(self::DATABASE_NAME) : $arg_connection; $statement = $connection->prepareStatement($sql); return self::populateObjects($statement->executeQuery(array(0 => $arg_domainUnifiedResourceName), ResultSet::FETCHMODE_NUM)); } }

63. <?php /** * Publications are the contextual point for all

    other objects * * @author Marijn Huizendveld <[email protected]> * @version $Revision: 163 $ changed by $Author: buroknapzak $ * * @copyright De Baas Media (2010) */ class kluPublicationPeer extends BasekluPublicationPeer { /** * Select the publications that have recently been updated. * * @param string $arg_connection * * @return array */ static public function retrieveRecentlyUpdatedForDomain ($arg_domainUnifiedResourceName = NULL, $arg_connect { $sql = "SELECT * FROM recently_updated WHERE domain = ? ORDER BY `updated_at` DESC"; $connection = NULL === $arg_connection ? Propel::getConnection(self::DATABASE_NAME) : $arg_connection; $statement = $connection->prepareStatement($sql); return self::populateObjects($statement->executeQuery(array(0 => $arg_domainUnifiedResourceName), ResultSe } }

64. Samenvatting

65. Samenvatting •Splitsen heeft het model betekenis gegeven •De interface is

    nu task-oriented •Het model kent de context van de data •Complexe queries zijn geëlimineerd

66. Vragen?

67. • http://cqrs.files.wordpress.com/2010/11/cqrs_documents.pdf • http://codebetter.com/gregyoung/2010/02/16/cqrs-task-based-uis-event-sourcing-agh/ • http://martinfowler.com/bliki/CQRS.html • http://www.viddler.com/v/dc528842 Meer informatie: