The document discusses leveraging graph databases in PHP applications. It provides an overview of graph databases, their data model consisting of nodes, properties and relationships. It then demonstrates connecting to Neo4j from PHP using the Neo4jPHP wrapper, querying the graph database with Cypher, and modeling a news feed content structure as a graph of connected content nodes. Sample code is shown for adding new content nodes to a user's news feed graph through a LASTPOST relationship.

1. Leveraging the Power of
Graph Databases
in PHP
Jeremy Kendall
Nashville PHP
November 2014

2. Obligatory Intro Slide

3. Also - New Father

4. What Kind of
Database?

5. Graphs != Charts
https://www.flickr.com/photos/markgroves/3065192499/

6. Graphs != Charts
http://stephenwildish.tumblr.com/post/101408321763/friday-project-witch-moral-compass

7. Graph Databases

8. Graph Databases
• Data Model!
• Nodes with properties
• Typed relationships

9. Graph Databases
• Data Model!
• Nodes with properties
• Typed relationships
• Strengths!
• Highly connected data
• ACID

10. Graph Databases
• Data Model!
• Nodes with properties
• Typed relationships
• Strengths!
• Highly connected data
• ACID
• Weaknesses!
• Paradigm shift

11. Graph Databases
• Data Model!
• Nodes with properties
• Typed relationships
• Strengths!
• Highly connected data
• ACID
• Weaknesses!
• Paradigm shift
• Examples!
• Neo4j, Titan, OrientDB

12. Why Care?

13. Why Care?
• All the NoSQL Joy
• Schema-less
• Semi-structured data

14. Why Care?
• All the NoSQL Joy
• Schema-less
• Semi-structured data
• Escape from JOIN Hell

15. Why Care?
• All the NoSQL Joy
• Schema-less
• Semi-structured data
• Escape from JOIN Hell
• Speed

16. Why Care?

17. Why Care?
• Relationships have 1st class status

18. Why Care?
• Relationships have 1st class status
• Just as important as the objects connecting them

19. Why Care?
• Relationships have 1st class status
• Just as important as the objects connecting them
• You can have properties & labels

20. Why Care?
• Relationships have 1st class status
• Just as important as the objects connecting them
• You can have properties & labels
• Multiple relationships

21. Why Care?

22. Speed
Depth MySQL Query Time Neo4j Query Time Records Returned
2 0.028 (28 MS) 0.04 ~900
3 0.213 0.06 ~999
4 10.273 0.07 ~999
5 92.613 0.07 ~999
1,000 people with an average 50 friends each

23. Crazy Speed
Depth MySQL Query Time Neo4j Query Time Records Returned
2 0.016 (16 MS) 0.01 ~2500
3 30.27 0.168 ~125,000
4 1543.505 1.359 ~600,000
5 Stopped after 1 hour 2.132 ~800,000
1,000,000 people with an average 50 friends each

24. Neo4j + Cypher

25. Cypher
• Neo4j’s declarative query language
• Easy to pick up
• Some clauses and concepts familiar from SQL

26. Simple Example

27. Goal

28. Create Some Nodes
CREATE (jk:Person { name: "Jeremy Kendall" })!
CREATE (gs:Company { name: "Graph Story" })!
!
CREATE (tn:State { name: "Tennessee" })!
CREATE (memphis:City { name: "Memphis" })!
CREATE (nashville:City { name: "Nashville" })!
!
CREATE (hotchicken:Food { name: "Hot Chicken" })!
CREATE (bbq:Food { name: "Barbecue" })!
CREATE (photography:Hobby { name: "Photography" })!
CREATE (language:Language { name: "PHP" })!
!
// . . . snip . . .!

29. Create Some Relationships
// . . . snip . . .!
!
CREATE (jk)-[:WORKS_AT { title: {"CTO"}]->(gs),!
(jk)-[:LIVES_IN]->(memphis)-[:LIVED_IN]->(nashville),!
(hotchicken)-[:ONLY_IN]->(nashville),!
(bbq)-[:ONLY_IN]->(memphis),!
(jk)-[:LOVES]->(hotchicken),!
!
// . . . snip . . .!

30. Create Some Relationships
// . . . snip . . .!
!
CREATE (jk)-[:WORKS_AT { title: {"CTO"}]->(gs),!
(jk)-[:LIVES_IN]->(memphis)-[:LIVED_IN]->(nashville),!
(hotchicken)-[:ONLY_IN]->(nashville),!
(bbq)-[:ONLY_IN]->(memphis),!
(jk)-[:LOVES]->(hotchicken),!
!
// . . . snip . . .!

31. Create Some Relationships
// . . . snip . . .!
!
CREATE (jk)-[:WORKS_AT { title: {"CTO"}]->(gs),!
(jk)-[:LIVES_IN]->(memphis)-[:LIVED_IN]->(nashville),!
(hotchicken)-[:ONLY_IN]->(nashville),!
(bbq)-[:ONLY_IN]->(memphis),!
(jk)-[:LOVES]->(hotchicken),!
!
// . . . snip . . .!

32. Create Some Relationships
// . . . snip . . .!
!
CREATE (jk)-[:WORKS_AT { title: {"CTO"}]->(gs),!
(jk)-[:LIVES_IN]->(memphis)-[:LIVED_IN]->(nashville),!
(hotchicken)-[:ONLY_IN]->(nashville),!
(bbq)-[:ONLY_IN]->(memphis),!
(jk)-[:LOVES]->(hotchicken),!
!
// . . . snip . . .!

33. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

34. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

35. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

36. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

37. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

38. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

39. Example Cypher Query
MATCH (p:Person { name: "Jeremy Kendall" })-[:LOVES]->(l)!
WITH p, l!
MATCH (p)-[:WORKS_AT]->(j)!
WITH p, l, j!
MATCH (p)-[:LIVES_IN]->(c:City)-[:LIVED_IN*0..]->(o:City)!
RETURN p, l, j, o

40. Query Result

41. Neo4j + PHP

42. Neo4jPHP
• PHP wrapper for the Neo4j REST API
• Installable via Composer
• Used internally at Graph Story
• Used in this presentation
• Well tested
• https://packagist.org/packages/everyman/
neo4jphp

43. Also see: NeoClient
• Written by Neoxygen
• Alternative PHP wrapper for the Neo4j REST API
• Installable via Composer
• Under review for internal use at Graph Story
• Well tested
• https://packagist.org/packages/neoxygen/neoclient

44. Connecting
$neo4jClient = new EverymanNeo4jClient(!
‘yourgraph.example.com’, !
7473!
);!
!
$neo4jClient->getTransport()!
->setAuth('username', 'password')!
->getTransport()->useHttps();

45. Creating a Node and Label
$node = new Node($neo4jClient);!
!
$label = $neo4jClient->makeLabel('Person');!
!
$node->setProperty('name', ‘Jeremy Kendall');!
!
$node->save()->addLabels(array($label));

46. Searching
// Searching for a label by property!
$label = $neo4jClient->makeLabel('Person');!
$nodes = $label->getNodes('name', $name);

47. Querying (Cypher)
$queryString = !
'MATCH (p:Person { name: { name }}) RETURN p';!
!
$query = new EverymanNeo4jCypherQuery(!
$neo4jClient,!
$queryString,!
['name' => ‘Jeremy Kendall']!
);!
!
$result = $query->getResultSet();

48. Named Parameters

49. Named Parameters
$queryString = !
'MATCH (p:Person { name: { name }}) RETURN p';!
!
$query = new EverymanNeo4jCypherQuery(!
$neo4jClient,!
$queryString,!
['name' => ‘Jeremy Kendall']!
);!
!
$result = $query->getResultSet();

50. Named Parameters
$queryString = !
'MATCH (p:Person { name: { name }}) RETURN p';!
!
$query = new EverymanNeo4jCypherQuery(!
$neo4jClient,!
$queryString,!
['name' => ‘Jeremy Kendall']!
);!
!
$result = $query->getResultSet();

51. Content Modeling:
News Feeds

52. News Feed
• Modeled as a list of posts
• Newest post first
• All subsequent posts follow
• Relationships: LASTPOST and NEXTPOST

53. LASTPOST

54. NEXTPOST

55. The Content Model
class Content!
{!
public $node;!
public $nodeId;!
public $contentId;!
public $title;!
public $url;!
public $tagstr;!
public $timestamp;!
public $userNameForPost;!
public $owner = false;!
}

56. Adding Content
public static function add($username, Content $content)!
{!
$queryString =<<<CYPHER!
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner!
CYPHER;!
!
$query = new Query(!
Neo4jClient::client(),!
$queryString,!
array(!
'u' => $username,!
'title' => $content->title,!
'url' => $content->url,!
'tagstr' => $content->tagstr,!
'timestamp' => time(),!
'contentId' => uniqid()!
)!
);!
$result = $query->getResultSet();!
!
return self::returnMappedContent($result);!
}

57. Adding Content
public static function add($username, Content $content)!
{!
$queryString =<<<CYPHER!
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner!
CYPHER;!
!
$query = new Query(!
Neo4jClient::client(),!
$queryString,!
array(!
'u' => $username,!
'title' => $content->title,!
'url' => $content->url,!
'tagstr' => $content->tagstr,!
'timestamp' => time(),!
'contentId' => uniqid()!
)!
);!
$result = $query->getResultSet();!
!
return self::returnMappedContent($result);!
}

58. Adding Content
public static function add($username, Content $content)!
{!
$queryString =<<<CYPHER!
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner!
CYPHER;!
!
$query = new Query(!
Neo4jClient::client(),!
$queryString,!
array(!
'u' => $username,!
'title' => $content->title,!
'url' => $content->url,!
'tagstr' => $content->tagstr,!
'timestamp' => time(),!
'contentId' => uniqid()!
)!
);!
$result = $query->getResultSet();!
!
return self::returnMappedContent($result);!
}

59. Adding Content
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:
{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner

60. Adding Content
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:
{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner

61. Adding Content
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:
{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner

62. Adding Content
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:
{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner

63. Adding Content
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:
{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner

64. Adding Content
MATCH (user { username: {u}})!
OPTIONAL MATCH (user)-[r:LASTPOST]->(lastpost)!
DELETE r!
CREATE (user)-[:LASTPOST]->(p:Content { title:{title}, url:
{url}, tagstr:{tagstr}, timestamp:{timestamp}, contentId:
{contentId} })!
WITH p, collect(lastpost) as lastposts!
FOREACH (x IN lastposts | CREATE p-[:NEXTPOST]->x)!
RETURN p, {u} as username, true as owner

65. Adding Content
$query = new Query(!
$neo4jClient,!
$queryString,!
array(!
'u' => $username,!
'title' => $content->title,!
'url' => $content->url,!
'tagstr' => $content->tagstr,!
'timestamp' => time(),!
'contentId' => uniqid()!
)!
);!
!
$result = $query->getResultSet();

66. Retrieving Content
public static function getContent($username, $skip)!
{!
$queryString = <<<CYPHER!
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4!
CYPHER;!
!
$query = new Query(!
Neo4jClient::client(),!
$queryString,!
array(!
'u' => $username,!
'skip' => $skip,!
)!
);!
!
$result = $query->getResultSet();!
!
return self::returnMappedContent($result);!
}

67. Retrieving Content
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4

68. Retrieving Content
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4

69. Retrieving Content
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4

70. Retrieving Content
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4

71. Retrieving Content
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4

72. Retrieving Content
MATCH (u:User { username: { u }})-[:FOLLOWS*0..1]->f!
WITH DISTINCT f, u!
MATCH f-[:LASTPOST]-lp-[:NEXTPOST*0..]-p!
RETURN p, f.username as username, f = u as owner!
ORDER BY p.timestamp desc SKIP { skip } LIMIT 4

73. Editing Content
public static function edit(Content $content)!
{!
$updatedAt = time();!
!
$node = $content->node;!
$node->setProperty('title', $content->title);!
$node->setProperty('url', $content->url);!
$node->setProperty('tagstr', $content->tagstr);!
$node->setProperty('updated', $updatedAt);!
$node->save();!
!
$content->updated = $updatedAt;!
!
return $content;!
}

74. Editing Content
public static function edit(Content $content)!
{!
$updatedAt = time();!
!
$node = $content->node;!
$node->setProperty('title', $content->title);!
$node->setProperty('url', $content->url);!
$node->setProperty('tagstr', $content->tagstr);!
$node->setProperty('updated', $updatedAt);!
$node->save();!
!
$content->updated = $updatedAt;!
!
return $content;!
}

75. Editing Content
public static function edit(Content $content)!
{!
$updatedAt = time();!
!
$node = $content->node;!
$node->setProperty('title', $content->title);!
$node->setProperty('url', $content->url);!
$node->setProperty('tagstr', $content->tagstr);!
$node->setProperty('updated', $updatedAt);!
$node->save();!
!
$content->updated = $updatedAt;!
!
return $content;!
}

76. Editing Content
public static function edit(Content $content)!
{!
$updatedAt = time();!
!
$node = $content->node;!
$node->setProperty('title', $content->title);!
$node->setProperty('url', $content->url);!
$node->setProperty('tagstr', $content->tagstr);!
$node->setProperty('updated', $updatedAt);!
$node->save();!
!
$content->updated = $updatedAt;!
!
return $content;!
}

77. Editing Content
public static function edit(Content $content)!
{!
$updatedAt = time();!
!
$node = $content->node;!
$node->setProperty('title', $content->title);!
$node->setProperty('url', $content->url);!
$node->setProperty('tagstr', $content->tagstr);!
$node->setProperty('updated', $updatedAt);!
$node->save();!
!
$content->updated = $updatedAt;!
!
return $content;!
}

78. Deleting Content
public static function delete($username, $contentId)!
{!
$queryString = self::getDeleteQueryString(!
$username, !
$contentId!
);!
!
$params = array(!
'username' => $username,!
'contentId' => $contentId,!
);!
!
$query = new Query(!
$neo4jClient,!
$queryString, !
$params!
);!
$query->getResultSet();!
}

79. Deleting Content
public static function delete($username, $contentId)!
{!
$queryString = self::getDeleteQueryString(!
$username, !
$contentId!
);!
!
$params = array(!
'username' => $username,!
'contentId' => $contentId,!
);!
!
$query = new Query(!
$neo4jClient,!
$queryString, !
$params!
);!
$query->getResultSet();!
}

80. Deleting Content
public static function delete($username, $contentId)!
{!
$queryString = self::getDeleteQueryString(!
$username, !
$contentId!
);!
!
$params = array(!
'username' => $username,!
'contentId' => $contentId,!
);!
!
$query = new Query(!
$neo4jClient,!
$queryString, !
$params!
);!
$query->getResultSet();!
}

81. Deleting Content
public static function delete($username, $contentId)!
{!
$queryString = self::getDeleteQueryString(!
$username, !
$contentId!
);!
!
$params = array(!
'username' => $username,!
'contentId' => $contentId,!
);!
!
$query = new Query(!
$neo4jClient,!
$queryString, !
$params!
);!
$query->getResultSet();!
}

82. Deleting Content: Leaf
// If leaf!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(c:Content { contentId: { contentId }})!
WITH c!
MATCH (c)-[r]-()!
DELETE c, r

83. Deleting Content: Leaf
// If leaf!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(c:Content { contentId: { contentId }})!
WITH c!
MATCH (c)-[r]-()!
DELETE c, r

84. Deleting Content: Leaf
// If leaf!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(c:Content { contentId: { contentId }})!
WITH c!
MATCH (c)-[r]-()!
DELETE c, r

85. Deleting Content: Leaf
// If leaf!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(c:Content { contentId: { contentId }})!
WITH c!
MATCH (c)-[r]-()!
DELETE c, r

86. Deleting Content: Leaf
// If leaf!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(c:Content { contentId: { contentId }})!
WITH c!
MATCH (c)-[r]-()!
DELETE c, r

87. Deleting Content: LASTPOST
// If last!
MATCH (u:User { username: { username }})-[lp:LASTPOST]-
>(del:Content { contentId: { contentId }})-[np:NEXTPOST]-
>(nextPost)!
CREATE UNIQUE (u)-[:LASTPOST]->(nextPost)!
DELETE lp, del, np

88. Deleting Content: LASTPOST
// If last!
MATCH (u:User { username: { username }})-[lp:LASTPOST]-
>(del:Content { contentId: { contentId }})-[np:NEXTPOST]-
>(nextPost)!
CREATE UNIQUE (u)-[:LASTPOST]->(nextPost)!
DELETE lp, del, np

89. Deleting Content: LASTPOST
// If last!
MATCH (u:User { username: { username }})-[lp:LASTPOST]-
>(del:Content { contentId: { contentId }})-[np:NEXTPOST]-
>(nextPost)!
CREATE UNIQUE (u)-[:LASTPOST]->(nextPost)!
DELETE lp, del, np

90. Deleting Content: LASTPOST
// If last!
MATCH (u:User { username: { username }})-[lp:LASTPOST]-
>(del:Content { contentId: { contentId }})-[np:NEXTPOST]-
>(nextPost)!
CREATE UNIQUE (u)-[:LASTPOST]->(nextPost)!
DELETE lp, del, np

91. Deleting Content: Other
// All other!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(before),!
(before)-[delBefore]->(del:Content { contentId:
{ contentId }})-[delAfter]->(after)!
CREATE UNIQUE (before)-[:NEXTPOST]->(after)!
DELETE del, delBefore, delAfter

92. Deleting Content: Other
// All other!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(before),!
(before)-[delBefore]->(del:Content { contentId:
{ contentId }})-[delAfter]->(after)!
CREATE UNIQUE (before)-[:NEXTPOST]->(after)!
DELETE del, delBefore, delAfter

93. Deleting Content: Other
// All other!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(before),!
(before)-[delBefore]->(del:Content { contentId:
{ contentId }})-[delAfter]->(after)!
CREATE UNIQUE (before)-[:NEXTPOST]->(after)!
DELETE del, delBefore, delAfter

94. Deleting Content: Other
// All other!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(before),!
(before)-[delBefore]->(del:Content { contentId:
{ contentId }})-[delAfter]->(after)!
CREATE UNIQUE (before)-[:NEXTPOST]->(after)!
DELETE del, delBefore, delAfter

95. Deleting Content: Other
// All other!
MATCH (u:User { username: { username }})-[:LASTPOST|
NEXTPOST*0..]->(before),!
(before)-[delBefore]->(del:Content { contentId:
{ contentId }})-[delAfter]->(after)!
CREATE UNIQUE (before)-[:NEXTPOST]->(after)!
DELETE del, delBefore, delAfter

96. Questions?

97. Thanks!
!
jeremy.kendall@graphstory.com
@JeremyKendall
http://www.graphstory.com