This document provides an overview of leveraging graph databases in PHP. It begins with an introduction to graph databases and their data model. It then discusses Neo4j, a popular graph database, and its query language Cypher. The document demonstrates connecting to Neo4j from PHP, creating and querying nodes and relationships, and provides an example of modeling content like a news feed as a graph using the LASTPOST and NEXTPOST relationships to link content in order.

1. Leveraging the Power of
Graph Databases
in PHP
Jeremy Kendall
Atlanta PHP
April 2015

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

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

9. Why Care?
• Relationships have 1st class status
• Just as important as the objects they connect
• You can have properties & labels
• Multiple relationships

10. Why Care?

11. 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

12. 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

14. Neo4j + Cypher

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

16. Simple Example

17. Goal

18. 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 . . .

19. 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 . . .

20. 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 . . .

21. 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 . . .

22. 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 . . .

23. 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

24. 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

25. 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

26. 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

27. 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

28. 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

29. 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

30. Query Result

31. However!

32. Easy to Model,
Challenging to Master

33. Subtle(-ish) Bug

34. Subtle(-ish) Bug

35. Neo4j + PHP

36. 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

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

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

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

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

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

42. Named Parameters

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

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

45. Content Modeling:
News Feeds
Graph Kit for PHP
https://github.com/GraphStory/graph-kit-php

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

47. LASTPOST

48. NEXTPOST

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

50. 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);
}

51. 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);
}

52. 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);
}

53. 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

54. 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

55. 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

56. 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

57. 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

58. 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

59. 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();

60. 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);
}

61. 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

62. 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

63. 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

64. 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

65. 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

66. 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

67. 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;
}

68. 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;
}

69. 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;
}

70. 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;
}

71. 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;
}

72. 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();
}

73. 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();
}

74. 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();
}

75. 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();
}

76. 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

77. 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

78. 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

79. 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

80. 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

81. 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

82. 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

83. 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

84. 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

85. 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

86. 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

87. 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

88. 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

89. 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

90. Questions?

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