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
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 <marijn@debaasmedia.nl> * @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 <marijn@debaasmedia.nl> * @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: