An introduction to Graph Databases in PHP, using Neo4j

Traditional relational databases — ironically — are not that good at the complex relationships some modern applications need.

Multiple joins and complex sub-queries can gradually take a toll on performance.

Graph Databases, on the other hand, are all about relationships. In this talk we will look at using the popular Neo4j graph database with PHP to build efficient relational data for OmNomHub: not your average recipe site.

Transcript

1. ( @michellesanver )-[:LOVES]->(Neo4j) Neo4J is AWESOME
2. ( @michellesanver )-[:LOVES]->(Neo4j) WIIIIIIIE \o/ “Learn the most by sharing your knowledge with others” - @coderabbi
3. This talk is entry-level ( @michellesanver )-[:LOVES]->(Neo4j) It’s Open Source
5. ( @michellesanver )-[:LOVES]->(Neo4j) Accent(s)!?
6. ( @michellesanver )-[:LOVES]->(Neo4j)
7. ( @michellesanver )-[:LOVES]->(Neo4j) I’m a data nerd Symfony is one of my main tools
8. ( @michellesanver )-[:LOVES]->(Neo4j) YOU New to Graph DBs?
9. ( @michellesanver )-[:LOVES]->(Neo4j) neo4j.com An open source graph database from Sweden
10. ( @michellesanver )-[:LOVES]->(Neo4j) Community Edition
11. ( @michellesanver )-[:LOVES]->(Neo4j) Enterprise Edition
12. ( @michellesanver )-[:LOVES]->(Neo4j) Meetups everywhere neo4j.meetup.com
13. ( @michellesanver )-[:LOVES]->(Neo4j) Graph theory has been studied since Leonard Euler’s Bridges 1736
14. ( @michellesanver )-[:LOVES]->(Neo4j) Body Text
15. ( @michellesanver )-[:LOVES]->(Neo4j)
16. ( @michellesanver )-[:LOVES]->(Neo4j) Graphs is data, that is connected… They are everywhere
17. ( @michellesanver )-[:LOVES]->(Neo4j) EVERYWHERE
18. ( @michellesanver )-[:LOVES]->(Neo4j)
19. ( @michellesanver )-[:LOVES]->(Neo4j) It’s modern.
20. ( @michellesanver )-[:LOVES]->(Neo4j) Facebook Open Graph
21. ( @michellesanver )-[:LOVES]->(Neo4j) Graphs \o/
22. ( @michellesanver )-[:LOVES]->(Neo4j) A graph is an easy way to visualise connected data. Michelle Graphs likes
23. ( @michellesanver )-[:LOVES]->(Neo4j) ( Nodes )
24. ( @michellesanver )-[:LOVES]->(Neo4j) (Node) { Properties } As many as you want Name: Michelle Nick: geekie Name: Cees-Jan Nick: WyriHaximus
25. ( @michellesanver )-[:LOVES]->(Neo4j) Nick: geekie Nick: WyriHaximus knows (Node) [ Relationships ] As many as you want
26. ( @michellesanver )-[:LOVES]->(Neo4j) Labels: As many as you want Nick: geekie Label: Person
27. ( @michellesanver )-[:LOVES]->(Neo4j) Indexes for easy lookup
28. ( @michellesanver )-[:LOVES]->(Neo4j) Constraints
29. ( @michellesanver )-[:LOVES]->(Neo4j) Constraints + Indexes = Optional schema
30. ( @michellesanver )-[:LOVES]->(Neo4j) Local McLaughlin graph
31. ( @michellesanver )-[:LOVES]->(Neo4j) Diamond Butterfly Bull Franklin Tutte Wagner
32. ( @michellesanver )-[:LOVES]->(Neo4j) You can make art out of your DB. (Don’t, or do?)
33. ( @michellesanver )-[:LOVES]->(Neo4j) Graphs vs. Relational
34. ( @michellesanver )-[:LOVES]->(Neo4j) Relational question: Get me all recipes for this user Graph question: What recipe should we recommend the user to cook next?
35. ( @michellesanver )-[:LOVES]->(Neo4j) Relational databases have tables Recipes
36. ( @michellesanver )-[:LOVES]->(Neo4j) Tables have relationships Recipes Groups
37. ( @michellesanver )-[:LOVES]->(Neo4j) Which causes a join table… Recipes Groups RecipeToGroup
38. ( @michellesanver )-[:LOVES]->(Neo4j) You query via the table Recipes Groups RecipeToGroup
39. ( @michellesanver )-[:LOVES]->(Neo4j) Imagine *actual* relationships Pasta (group) Spaghetti
 Bolognese
 (recipe) Italian (group) is_in is_in
40. ( @michellesanver )-[:LOVES]->(Neo4j) Relational vs. Graph (1) Spaghetti Bolognese (2) Pasta (1) Italian Recipes Groups RecipeToGroup recipeId:1 | groupId: 1 recipeId:1 | groupId: 2 Pasta (group) Spaghetti
 Bolognese
 (recipe) Italian (group) is_in is_in
41. ( @michellesanver )-[:LOVES]->(Neo4j) (1) Name: Pasta … Ingredients (1) Spaghetti Bolognese (2) Pasta (1) Italian Recipes Groups RecipeToGroup recipeId:1 | groupId: 1 recipeId:1 | groupId: 2 IngredientId: 1 RecipeId: 1 Unit: g Amount: 500 IngredientToRecipe (2) Name: Meat … IngredientId: 2 RecipeId: 1 Unit: g Amount: 800
42. ( @michellesanver )-[:LOVES]->(Neo4j) Pasta (group) Italian (group) is_in is_in Italian (group) Meat (Ingredient) Pasta (Ingredient) contains amount: 500 unit: g contains
 amount: 800 unit: g Spaghetti
 Bolognese
 (recipe)
43. ( @michellesanver )-[:LOVES]->(Neo4j) Joins in relational Performance degrades exponentially Corresponding in Neo4j Linear performance
44. ( @michellesanver )-[:LOVES]->(Neo4j) Up to four million hops per second and core
45. ( @michellesanver )-[:LOVES]->(Neo4j) Whiteboard Friendly
46. ( @michellesanver )-[:LOVES]->(Neo4j) Relational databases have a structure
47. ( @michellesanver )-[:LOVES]->(Neo4j) Neo4j has an optional structure
48. ( @michellesanver )-[:LOVES]->(Neo4j) A big query. The EAV model.
49. ( @michellesanver )-[:LOVES]->(Neo4j) SET @entityid = '3'; SELECT ea.attribute_id, ea.attribute_code, eav.value AS 'value', 'varchar' AS 'type' FROM catalog_category_entity e JOIN catalog_category_entity_varchar eav ON e.entity_id = eav.entity_id JOIN eav_attribute ea ON eav.attribute_id = ea.attribute_id WHERE e.entity_id = @entityid UNION SELECT ea.attribute_id, ea.attribute_code, eav.value AS 'value', 'int' AS 'type' FROM catalog_category_entity e JOIN catalog_category_entity_int eav ON e.entity_id = eav.entity_id JOIN eav_attribute ea ON eav.attribute_id = ea.attribute_id WHERE e.entity_id = @entityid UNION
50. ( @michellesanver )-[:LOVES]->(Neo4j) SELECT ea.attribute_id, ea.attribute_code, eav.value AS 'value', 'decimal' AS 'type' FROM catalog_category_entity e JOIN catalog_category_entity_decimal eav ON e.entity_id = eav.entity_id JOIN eav_attribute ea ON eav.attribute_id = ea.attribute_id WHERE e.entity_id = @entityid UNION selecting ea.attribute_id, ea.attribute_code, eav.value AS 'value', 'datetime' AS 'type' FROM catalog_category_entity e JOIN catalog_category_entity_datetime eav ON e.entity_id = eav.entity_id JOIN eav_attribute ea ON eav.attribute_id = ea.attribute_id WHERE e.entity_id = @entityid UNION SELECT ea.attribute_id, ea.attribute_code, eav.value AS 'value', 'text' AS 'type' FROM catalog_category_entity e JOIN catalog_category_entity_text eav ON e.entity_id = eav.entity_id JOIN eav_attribute ea ON eav.attribute_id = ea.attribute_id WHERE e.entity_id = @entityid
51. ( @michellesanver )-[:LOVES]->(Neo4j) Flexibility in a structured database is expensive.
52. Choose the right tool for the right job.
53. ( @michellesanver )-[:LOVES]->(Neo4j) OmNomHub My pet project that is never done.
54. ( @michellesanver )-[:LOVES]->(Neo4j) Fork A Recipe
55. ( @michellesanver )-[:LOVES]->(Neo4j) Send change requests
56. ( @michellesanver )-[:LOVES]->(Neo4j) Join groups and share recipe collections among them
57. ( @michellesanver )-[:LOVES]->(Neo4j) Have your own private recipe collections
58. ( @michellesanver )-[:LOVES]->(Neo4j) Search similar recipes (This is a part where the graph structure shines)
59. ( @michellesanver )-[:LOVES]->(Neo4j) Neo4j architecture
60. ( @michellesanver )-[:LOVES]->(Neo4j) Disks File System Cache Record Files Object Cache Cypher Core API Traversal API Transaction Management Transaction Log
61. ( @michellesanver )-[:LOVES]->(Neo4j) Disks File System Cache Record Files Object Cache Cypher Core API Traversal API Transaction Management Transaction Log
62. ( @michellesanver )-[:LOVES]->(Neo4j) Disks File System Cache Record Files Object Cache Cypher Core API Traversal API Transaction Management Transaction Log
63. ( @michellesanver )-[:LOVES]->(Neo4j) Disks File System Cache Record Files Object Cache Cypher Core API Traversal API Transaction Management Transaction Log
64. ( @michellesanver )-[:LOVES]->(Neo4j) Disks File System Cache Record Files Object Cache Cypher Core API Traversal API Transaction Management Transaction Log
65. ( @michellesanver )-[:LOVES]->(Neo4j) Cypher Like SQL for graph databases.
66. ( @michellesanver )-[:LOVES]->(Neo4j) ) Parentheses means nodes (Or hugs) (
67. ( @michellesanver )-[:LOVES]->(Neo4j) } Curly braces means properties {
68. ( @michellesanver )-[:LOVES]->(Neo4j) ] Square brackets means relationships [
69. ( @michellesanver )-[:LOVES]->(Neo4j) Makes it easy to visualise and query the data. Browser
70. DEMO: Cypher and Browser ( @michellesanver )-[:LOVES]->(Neo4j)
71. ( @michellesanver )-[:LOVES]->(Neo4j) Neo4j architecture Neostore File Storage
72. ( @michellesanver )-[:LOVES]->(Neo4j) Neostore has several different store files
73. ( @michellesanver )-[:LOVES]->(Neo4j) Each store has specific data
74. ( @michellesanver )-[:LOVES]->(Neo4j) Nodes neostore.nodestore.db 9 bytes
75. ( @michellesanver )-[:LOVES]->(Neo4j) Neostore Fixed size === FAST
76. ( @michellesanver )-[:LOVES]->(Neo4j) Relationships neostore.relationshipstore.db 33 bytes
77. ( @michellesanver )-[:LOVES]->(Neo4j) Properties neostore.propertystore.db neostore.propertystore.db.index neostore.propertystore.db.strings neostore.propertystore.db.arrays
78. ( @michellesanver )-[:LOVES]->(Neo4j) Hardware matters!
79. ( @michellesanver )-[:LOVES]->(Neo4j) Caching in memory, or filesystem
80. ( @michellesanver )-[:LOVES]->(Neo4j) OmNomHub The future* * Maybe when my son moved away from home… In a land, far far away
81. ( @michellesanver )-[:LOVES]->(Neo4j) Connecting users “You both like”
82. ( @michellesanver )-[:LOVES]->(Neo4j) Connecting recipes “These have similar ingredients and user base”
83. ( @michellesanver )-[:LOVES]->(Neo4j) Being smart “You might like”
84. ( @michellesanver )-[:LOVES]->(Neo4j) Being smart Smart recipe collections!
85. ( @michellesanver )-[:LOVES]->(Neo4j) Being creepy “Don’t like meat huh?”
86. ( @michellesanver )-[:LOVES]->(Neo4j) Neo4j in PHP
87. ( @michellesanver )-[:LOVES]->(Neo4j) As we saw There’s a REST interface!
88. ( @michellesanver )-[:LOVES]->(Neo4j) GraphAware PHP Client https://github.com/graphaware/neo4j-php-client
89. ( @michellesanver )-[:LOVES]->(Neo4j) $client = ClientBuilder::create()
 ->addConnection('bolt', 'bolt://neo4j:password@localhost:7687')
 ->build(); 
 $query = "MATCH (n:User) RETURN n.name”;
 $result = $client->run($query);
 
 foreach ($result->getRecords() as $record) {
 echo(count($record->value('name'));
 }

90. ( @michellesanver )-[:LOVES]->(Neo4j) $client = ClientBuilder::create()
 ->addConnection('bolt', 'bolt://neo4j:password@localhost:7687')
 ->build(); 
 $query = "MATCH (n:User) RETURN n.name”;
 $result = $client->run($query);
 
 foreach ($result->getRecords() as $record) {
 echo(count($record->value('name'));
 }

91. ( @michellesanver )-[:LOVES]->(Neo4j) $client = ClientBuilder::create()
 ->addConnection('bolt', 'bolt://neo4j:password@localhost:7687')
 ->build(); 
 $query = "MATCH (n:User) RETURN n.name”;
 $result = $client->run($query);
 
 foreach ($result->getRecords() as $record) {
 echo(count($record->value('name'));
 }

92. ( @michellesanver )-[:LOVES]->(Neo4j) $client = ClientBuilder::create()
 ->addConnection('bolt', 'bolt://neo4j:password@localhost:7687')
 ->build(); 
 $query = "MATCH (n:User) RETURN n.name”;
 $result = $client->run($query);
 
 foreach ($result->getRecords() as $record) {
 echo(count($record->get('name'));
 }

93. ( @michellesanver )-[:LOVES]->(Neo4j) GraphAware also released an OGM
94. ( @michellesanver )-[:LOVES]->(Neo4j) /**
 * @OGM\GraphId()
 * @var int
 */
 protected $id;
 
 /**
 * @OGM\Property(type="string")
 * @var string
 */
 protected $recipeName;
 
 /**
 * @OGM\Relationship(type="FORKED", direction="OUTGOING", targetEntity="User", collection=true)
 * @var ArrayCollection|User[]
 */
 protected $users;
95. ( @michellesanver )-[:LOVES]->(Neo4j) /**
 * @OGM\GraphId()
 * @var int
 */
 protected $id;
 
 /**
 * @OGM\Property(type="string")
 * @var string
 */
 protected $recipeName;
 
 /**
 * @OGM\Relationship(type="FORKED", direction="OUTGOING", targetEntity="User", collection=true)
 * @var ArrayCollection|User[]
 */
 protected $users;
96. ( @michellesanver )-[:LOVES]->(Neo4j) /**
 * @OGM\GraphId()
 * @var int
 */
 protected $id;
 
 /**
 * @OGM\Property(type="string")
 * @var string
 */
 protected $recipeName;
 
 /**
 * @OGM\Relationship(type="FORKED", direction="OUTGOING", targetEntity="User", collection=true)
 * @var ArrayCollection|User[]
 */
 protected $users;
97. ( @michellesanver )-[:LOVES]->(Neo4j) /**
 * @OGM\GraphId()
 * @var int
 */
 protected $id;
 
 /**
 * @OGM\Property(type="string")
 * @var string
 */
 protected $recipeName;
 
 /**
 * @OGM\Relationship(type="FORKED", direction="OUTGOING", targetEntity="User", collection=true)
 * @var ArrayCollection|User[]
 */
 protected $users;
98. ( @michellesanver )-[:LOVES]->(Neo4j) $user = $em->getRepository(User::class) ->findOneBy(‘name’, 'Michelle');
99. ( @michellesanver )-[:LOVES]->(Neo4j) Neo4j + PHP is well documented https://neo4j.com/developer/php/ https://github.com/graphaware/neo4j-php-client https://github.com/graphaware/neo4j-php-ogm
100. ( @michellesanver )-[:LOVES]->(Neo4j) Wrapup
101. ( @michellesanver )-[:LOVES]->(Neo4j) Graphs are everywhere
102. ( @michellesanver )-[:LOVES]->(Neo4j) Graphs make it easier to visualise complex data
103. ( @michellesanver )-[:LOVES]->(Neo4j) Graphs make it easier to… Be creepily smart <3
104. ( @michellesanver )-[:LOVES]->(Neo4j) Resources neo4j.org/learn neo4j.com/developer/php github.com/neo4j-contrib/neo4j-symfony
105. ( @michellesanver )-[:LOVES]->(Neo4j) Thank you Questions?
106. ( @michellesanver )-[:LOVES]->(Neo4j) YOU are AWESOME Thank you
107. ( @michellesanver )-[:LOVES]->(Neo4j) Graph databases How would you use them?