This document summarizes the evolution of Neo4j's developer surface over time, including the introduction of Bolt drivers, user defined procedures, functions, and aggregation functions. It provides examples of how to write and call user defined procedures and functions in Java to extend Neo4j's capabilities for analytics and operations.

1. Utilizing Powerful Extensions
for Analytics and Operations
Mark Needham
Developer Relations Engineer, Neo4j

2. ~ 30 things in 30 minutes

3. Neo4j Developer Surface
Native LanguageDrivers
BOLT User Defined
Procedure
2000-2010 0.x Embedded Java API
2010-2014 1.x REST
2014-2015 2.x Cypher over HTTP
2016 3.0.x Bolt, Official Language Drivers, User Defined Procedures
2016 3.1.x User Defined Functions
2017 3.2.x User Defined Aggregation Functions

4. Neo4j Developer Surface
Native LanguageDrivers
BOLT User Defined
Procedure
2000-2010 0.x Embedded Java API
2010-2014 1.x REST
2014-2015 2.x Cypher over HTTP
2016 3.0.x Bolt, Official Language Drivers, User Defined Procedures
2016 3.1.x User Defined Functions
2017 3.2.x User Defined Aggregation Functions

5. Neo4j Bolt Drivers

6. Official Drivers

7. Community Drivers

8. Neo4j Developer Surface
Native LanguageDrivers
BOLT User Defined
Procedure
2000-2010 0.x Embedded Java API
2010-2014 1.x REST
2014-2015 2.x Cypher over HTTP
2016 3.0.x Bolt, Official Language Drivers, User Defined Procedures
2016 3.1.x User Defined Functions
2017 3.2.x User Defined Aggregation Functions

9. Procedures
Functions
Aggregate Functions

10. Can be written in any JVM language

11. User Defined
Procedures
11

12. Callable Standalone
and in
Cypher Statements

13. public class FullTextIndex {
@Context
public GraphDatabaseService db;
@Procedure( name = "example.search", mode = Procedure.Mode.READ )
public Stream<SearchHit> search( @Name("index") String index,
@Name("query") String query ) {
if( !db.index().existsForNodes( index )) {
return Stream.empty();
}
return db.index().forNodes( index ).query( query ).stream()
.map( SearchHit::new );
}
public static class SearchHit {
public final Node node;
SearchHit(Node node) { this.node = node; }
}
}

14. public class FullTextIndex {
@Context
public GraphDatabaseService db;
@Procedure( name = "example.search", mode = Procedure.Mode.READ )
public Stream<SearchHit> search( @Name("index") String index,
@Name("query") String query ) {
if( !db.index().existsForNodes( index )) {
return Stream.empty();
}
return db.index().forNodes( index ).query( query ).stream()
.map( SearchHit::new );
}
public static class SearchHit {
public final Node node;
SearchHit(Node node) { this.node = node; }
}
}

15. public class FullTextIndex {
@Context
public GraphDatabaseService db;
@Procedure( name = "example.search", mode = Procedure.Mode.READ )
public Stream<SearchHit> search( @Name("index") String index,
@Name("query") String query ) {
if( !db.index().existsForNodes( index )) {
return Stream.empty();
}
return db.index().forNodes( index ).query( query ).stream()
.map( SearchHit::new );
}
public static class SearchHit {
public final Node node;
SearchHit(Node node) { this.node = node; }
}
}

16. try ( Driver driver = GraphDatabase.driver( "bolt://localhost",
Config.build().toConfig() ) ) {
try ( Session session = driver.session() ) {
String call = "CALL example.search('User',$query)";
Map<String,Object> params = singletonMap( "query", "name:Brook*");
StatementResult result = session.run( call, params);
while ( result.hasNext() {
// process results
}
}
}

17. try ( Driver driver = GraphDatabase.driver( "bolt://localhost",
Config.build().toConfig() ) ) {
try ( Session session = driver.session() ) {
String call = "CALL example.search('User',$query)";
Map<String,Object> params = singletonMap( "query", "name:Brook*");
StatementResult result = session.run( call, params);
while ( result.hasNext() {
// process results
}
}
}

18. User Defined
Functions
18

19. Useable in any Cypher
expression or lightweight
computation

20. public class Join {
@UserFunction
@Description("example.join(['s1','s2',...], delimiter)
- join the given strings with the given delimiter.")
public String join(
@Name("strings") List<String> strings,
@Name(value = "delimiter", defaultValue = ",") String delimiter ) {
if ( strings == null || delimiter == null ) {
return null;
}
return String.join( delimiter, strings );
}
}

21. public class Join {
@UserFunction
@Description("example.join(['s1','s2',...], delimiter)
- join the given strings with the given delimiter.")
public String join(
@Name("strings") List<String> strings,
@Name(value = "delimiter", defaultValue = ",") String delimiter ) {
if ( strings == null || delimiter == null ) {
return null;
}
return String.join( delimiter, strings );
}
}

22. public class Join {
@UserFunction
@Description("example.join(['s1','s2',...], delimiter)
- join the given strings with the given delimiter.")
public String join(
@Name("strings") List<String> strings,
@Name(value = "delimiter", defaultValue = ",") String delimiter ) {
if ( strings == null || delimiter == null ) {
return null;
}
return String.join( delimiter, strings );
}
}

23. try ( Driver driver = GraphDatabase.driver( "bolt://localhost",
Config.build().toConfig() ) )
{
try ( Session session = driver.session() )
{
String query = "RETURN example.join(['Hello', 'World']) AS result";
String result = session.run( query )
.single().get( "result" ).asString();
}
}

24. User Defined
Aggregation Functions
24

25. Custom, efficient aggregations
for Data Science and BI

26. public class LongestString {
@UserAggregationFunction
@Description( "aggregates the longest string found" )
public LongStringAggregator longestString() {
return new LongStringAggregator();
}
public static class LongStringAggregator {
private int longest;
private String longestString;
@UserAggregationUpdate
public void findLongest( @Name( "string" ) String string ) {
if ( string != null && string.length() > longest) {
longest = string.length();
longestString = string;
}
}
@UserAggregationResult
public String result() { return longestString; }
}
}

27. public class LongestString {
@UserAggregationFunction
@Description( "aggregates the longest string found" )
public LongStringAggregator longestString() {
return new LongStringAggregator();
}
public static class LongStringAggregator {
private int longest;
private String longestString;
@UserAggregationUpdate
public void findLongest( @Name( "string" ) String string ) {
if ( string != null && string.length() > longest) {
longest = string.length();
longestString = string;
}
}
@UserAggregationResult
public String result() { return longestString; }
}
}

28. public class LongestString {
@UserAggregationFunction
@Description( "aggregates the longest string found" )
public LongStringAggregator longestString() {
return new LongStringAggregator();
}
public static class LongStringAggregator {
private int longest;
private String longestString;
@UserAggregationUpdate
public void findLongest( @Name( "string" ) String string ) {
if ( string != null && string.length() > longest) {
longest = string.length();
longestString = string;
}
}
@UserAggregationResult
public String result() { return longestString; }
}
}

29. public class LongestString {
@UserAggregationFunction
@Description( "aggregates the longest string found" )
public LongStringAggregator longestString() {
return new LongStringAggregator();
}
public static class LongStringAggregator {
private int longest;
private String longestString;
@UserAggregationUpdate
public void findLongest( @Name( "string" ) String string ) {
if ( string != null && string.length() > longest) {
longest = string.length();
longestString = string;
}
}
@UserAggregationResult
public String result() { return longestString; }
}
}

30. try ( Driver driver = GraphDatabase.driver( "bolt://localhost",
Config.build().toConfig() ) ) {
try ( Session session = driver.session() ) {
String query = "UNWIND ['abc', 'abcd', 'ab'] AS string " +
"RETURN example.longestString(string) AS result";
String result = session.run(query).single().get("result").asString();
}
}

33. Awesome Procedures
On Cypher

36. > 300
procedures and functions

39. Data Integration

40. Load from a relational database

41. apoc.load.jdbc
WITH "jdbc:mysql://localhost:3306/northwind?user=root" AS url
CALL apoc.load.jdbc(url,"products")
YIELD row
MERGE (p:Product {id: row.ProductID})
SET p.name = row.ProductName, p.unitPrice = row.UnitPrice

42. WITH "jdbc:mysql://localhost:3306/northwind?user=root" AS url
CALL apoc.load.jdbc(url,"products")
YIELD row
MERGE (p:Product {id: row.ProductID})
SET p.name = row.ProductName, p.unitPrice = row.UnitPrice
Execute procedure

43. Apply Cypher transformation
WITH "jdbc:mysql://localhost:3306/northwind?user=root" AS url
CALL apoc.load.jdbc(url,"products")
YIELD row
MERGE (p:Product {id: row.ProductID})
SET p.name = row.ProductName, p.unitPrice = row.UnitPrice

44. Load XML

45. apoc.load.xml
CALL apoc.load.xml('http://overpass.osm.rambler.ru/cgi/xapi_meta?*[bbox=11.54,48.14,11.543,48.145]')
YIELD value
UNWIND value["_children"] AS child
WITH child WHERE child["_type"] = "node"
WITH child.id AS id,
child.lat AS latitude,
child.lon AS longitude,
child["user"] AS userName
MERGE (point:Point {id: id})
SET point.latitude = latitude,
point.longitude = longitude
MERGE (user:User {name: userName})
MERGE (user)-[:EDITED]->(point)

46. Execute procedure
CALL apoc.load.xml('http://overpass.osm.rambler.ru/cgi/xapi_meta?*[bbox=11.54,48.14,11.543,48.145]')
YIELD value
UNWIND value["_children"] AS child
WITH child WHERE child["_type"] = "node"
WITH child.id AS id,
child.lat AS latitude,
child.lon AS longitude,
child["user"] AS userName
MERGE (point:Point {id: id})
SET point.latitude = latitude,
point.longitude = longitude
MERGE (user:User {name: userName})
MERGE (user)-[:EDITED]->(point)

47. UNWIND the array of elements
CALL apoc.load.xml('http://overpass.osm.rambler.ru/cgi/xapi_meta?*[bbox=11.54,48.14,11.543,48.145]')
YIELD value
UNWIND value["_children"] AS child
WITH child WHERE child["_type"] = "node"
WITH child.id AS id,
child.lat AS latitude,
child.lon AS longitude,
child["user"] AS userName
MERGE (point:Point {id: id})
SET point.latitude = latitude,
point.longitude = longitude
MERGE (user:User {name: userName})
MERGE (user)-[:EDITED]->(point)

48. Filter rows
CALL apoc.load.xml('http://overpass.osm.rambler.ru/cgi/xapi_meta?*[bbox=11.54,48.14,11.543,48.145]')
YIELD value
UNWIND value["_children"] AS child
WITH child WHERE child["_type"] = "node"
WITH child.id AS id,
child.lat AS latitude,
child.lon AS longitude,
child["user"] AS userName
MERGE (point:Point {id: id})
SET point.latitude = latitude,
point.longitude = longitude
MERGE (user:User {name: userName})
MERGE (user)-[:EDITED]->(point)

49. Apply Cypher transformation
CALL apoc.load.xml('http://overpass.osm.rambler.ru/cgi/xapi_meta?*[bbox=11.54,48.14,11.543,48.145]')
YIELD value
UNWIND value["_children"] AS child
WITH child WHERE child["_type"] = "node"
WITH child.id AS id,
child.lat AS latitude,
child.lon AS longitude,
child["user"] AS userName
MERGE (point:Point {id: id})
SET point.latitude = latitude,
point.longitude = longitude
MERGE (user:User {name: userName})
MERGE (user)-[:EDITED]->(point)
MERGE (point:Point {id: id})
SET point.latitude = latitude,
point.longitude = longitude
MERGE (user:User {name: userName})
MERGE (user)-[:EDITED]->(point)

50. Load JSON

51. apoc.load.json
WITH "https://api.stackexchange.com/2.2/questions?pagesize=100&order=desc&sort=creation&tagged=neo4j&site=stackoverflow&filter=!5-i6Zw8Y)4W7vpy91PMYsKM-k9yzEsSC1_Uxlf" AS url
CALL apoc.load.json(url) YIELD value
UNWIND value.items AS q
MERGE (question:Question {id:q.question_id})
ON CREATE SET question.title = q.title,
question.share_link = q.share_link,
question.favorite_count = q.favorite_count
MERGE (owner:User {id:q.owner.user_id})
ON CREATE SET owner.display_name = q.owner.display_name
MERGE (owner)-[:ASKED]->(question)
FOREACH (tagName IN q.tags |
MERGE (tag:Tag {name:tagName}) MERGE (question)-[:TAGGED]->(tag))
FOREACH (a IN q.answers |
MERGE (question)<-[:ANSWERS]-(answer:Answer {id:a.answer_id})
MERGE (answerer:User {id:a.owner.user_id})
ON CREATE SET answerer.display_name = a.owner.display_name
MERGE (answer)<-[:PROVIDED]-(answerer)
)

52. WITH "https://api.stackexchange.com/2.2/questions?pagesize=100&order=desc&sort=creation&tagged=neo4j&site=stackoverflow&filter=!5-i6Zw8Y)4W7vpy91PMYsKM-k9yzEsSC1_Uxlf" AS url
CALL apoc.load.json(url) YIELD value
UNWIND value.items AS q
MERGE (question:Question {id:q.question_id})
ON CREATE SET question.title = q.title,
question.share_link = q.share_link,
question.favorite_count = q.favorite_count
MERGE (owner:User {id:q.owner.user_id})
ON CREATE SET owner.display_name = q.owner.display_name
MERGE (owner)-[:ASKED]->(question)
FOREACH (tagName IN q.tags |
MERGE (tag:Tag {name:tagName}) MERGE (question)-[:TAGGED]->(tag))
FOREACH (a IN q.answers |
MERGE (question)<-[:ANSWERS]-(answer:Answer {id:a.answer_id})
MERGE (answerer:User {id:a.owner.user_id})
ON CREATE SET answerer.display_name = a.owner.display_name
MERGE (answer)<-[:PROVIDED]-(answerer)
)
Use FOREACH for arrays within a row
FOREACH (tagName IN q.tags |
MERGE (tag:Tag {name:tagName}) MERGE (question)-[:TAGGED]->(tag))
FOREACH (a IN q.answers |
MERGE (question)<-[:ANSWERS]-(answer:Answer {id:a.answer_id})
MERGE (answerer:User {id:a.owner.user_id})
ON CREATE SET answerer.display_name = a.owner.display_name
MERGE (answer)<-[:PROVIDED]-(answerer)
)

53. Graph Refactorings

54. apoc.refactor.mergeNodes
MATCH (n:Person)
WITH n.email AS email, collect(n) as people
WHERE size(people) > 1
CALL apoc.refactor.mergeNodes(people)
YIELD node
RETURN node

55. apoc.refactor.mergeNodes
MATCH (n:Person)
WITH n.email AS email, collect(n) as people
WHERE size(people) > 1
CALL apoc.refactor.mergeNodes(people)
YIELD node
RETURN node

56. apoc.create.addLabels
MATCH (n:Movie)
CALL apoc.create.addLabels( id(n), [ n.genre ] ) YIELD node
REMOVE node.genre
RETURN node

57. Cypher Execution

58. Run large scale updates
CALL apoc.periodic.iterate(
'MATCH (n:Person) RETURN n',
'SET n.name = n.firstName + " " + n.lastName',
{batchSize:10000, iterateList:true, parallel:true})

59. Utility Functions

60. Compute soundex encoding of a string
CALL apoc.text.phonetic('Hello, dear User!')
YIELD value
RETURN value
// will return 'H436'

61. How similar do two strings sound?
CALL apoc.text.phoneticDelta(
'Hello Mr Rabbit', 'Hello Mr Ribbit')
// will return '4' (very similar)

62. Extract domain names
WITH 'http://www.example.com/all-the-things' AS url
RETURN apoc.data.domain(url)
// will return 'www.example.com'

63. Date to Timestamp
RETURN apoc.date.parse(
'2015/03/25 03:15:59',
's',
'yyyy/MM/dd HH:mm:ss'
)
// will return 1427253359

64. Timestamp to Date
RETURN apoc.date.format(
1427253359,
's',
'yyyy/MM/dd HH:mm:ss'
)
// will return "2015/03/25 03:15:59"

65. And many more!

66. RDF and Graphs

69. Import RDF triples

70. semantics.importRDF
CALL semantics.importRDF("file:///industry.ntriples","N-Triples", {})

71. Thomson Reuters' OpenPermID Graph

72. Graph Aided Search

76. com.graphaware.runtime.enabled=true
#ES becomes the module ID:
com.graphaware.module.ES.2=com.graphaware.module.es.ElasticSearchModuleBootstrapper
#URI of Elasticsearch
com.graphaware.module.ES.uri=localhost
#Port of Elasticsearch
com.graphaware.module.ES.port=9201
conf/neo4j.conf

77. CALL ga.es.queryNode('{"query":
{"match":{"name":"alessandro"}}}')
YIELD node, score
RETURN node, score
Find nodes

78. CALL ga.es.queryRelationship('{"query":
{"match":{"city":"paris"}}}')
YIELD relationship, score
RETURN relationship, score
Find relationships

79. dzone.com/refcardz/graph-powered-search-neo4j-amp-elasticsearch

80. Versioned Graphs

83. CALL graph.versioner.init('Person',
{ssn: 123456789, name: 'Marco'},
{address: 'Via Roma 11'}
)
Create node

84. CALL graph.versioner.init('Person',
{ssn: 123456789, name: 'Marco'},
{address: 'Via Roma 11'}
)
Immutable properties

85. CALL graph.versioner.init('Person',
{ssn: 123456789, name: 'Marco'},
{address: 'Via Roma 11'}
)
State properties

86. MATCH (p:Person {name: "Marco"})
WITH p
CALL graph.versioner.update(p, {address: 'Via Roma 12'})
YIELD node
RETURN node
Update state

87. MATCH (p:Person {name: "Marco"})
WITH p
CALL graph.versioner.update(p, {address: 'Via Roma 12'})
YIELD node
RETURN node
Pass in the new state

88. Spatial

90. CALL spatial.addWKTLayer('geom', 'wkt')
Create spatial index

91. MATCH (d:District)
WITH collect(d) AS districts
CALL spatial.addNodes('geom', districts) YIELD node
RETURN count(*)
Add nodes to spatial index

92. MATCH (d:District)
WITH collect(d) AS districts
CALL spatial.addNodes('geom', districts) YIELD node
RETURN count(*)
Collect nodes to pass in

93. CALL spatial.withinDistance('geom',
{latitude: 37.563440, longitude: -122.322265}, 1)
YIELD node AS d
WITH d, d.wkt AS wkt, d.state AS state, d.district AS district
LIMIT 1
MATCH (d)<-[:REPRESENTS]-(l:Legislator)
MATCH (l)-[:SERVES_ON]->(c:Committee)
MATCH (c)<-[:REFERRED_TO]-(b:Bill)
MATCH (b)-[:DEALS_WITH]->(s:Subject)
RETURN *
Query nodes by location

94. CALL spatial.withinDistance('geom',
{latitude: 37.563440, longitude: -122.322265}, 1)
YIELD node AS d
WITH d, d.wkt AS wkt, d.state AS state, d.district AS district
LIMIT 1
MATCH (d)<-[:REPRESENTS]-(l:Legislator)
MATCH (l)-[:SERVES_ON]->(c:Committee)
MATCH (c)<-[:REFERRED_TO]-(b:Bill)
MATCH (b)-[:DEALS_WITH]->(s:Subject)
RETURN *
Finds nodes within 1km

95. Graph Based
Machine Learning

99. CREATE (n:News)
SET n.text = "Scores of people were already lying dead or
injured inside a crowded Orlando nightclub,
and the police had spent hours trying to connect with the
gunman and end the situation without further violence.
But when Omar Mateen threatened to set off explosives, the
police decided to act, and pushed their way through a
wall to end the bloody standoff."
Annotating text

100. MATCH (n:News)
CALL ga.nlp.annotate({text: n.text, id: id(n)})
YIELD result
MERGE (n)-[:HAS_ANNOTATED_TEXT]->(result)
RETURN result
Annotating text

101. MATCH (n:News)
CALL ga.nlp.annotate({text: n.text, id: id(n)})
YIELD result
MERGE (n)-[:HAS_ANNOTATED_TEXT]->(result)
RETURN result
Execute procedure

102. MATCH (n:News)
CALL ga.nlp.annotate({text: n.text, id: id(n)})
YIELD result
MERGE (n)-[:HAS_ANNOTATED_TEXT]->(result)
RETURN result
Apply Cypher transformation

103. Graph Algorithms

104. Graph of Thrones

105. Graph of Thrones

106. Insights from Algorithms

107. Graph of Thrones

108. Graph of Thrones

109. Determines the
importance of distinct
nodes in the network
Finds the optimal path or
evaluates route availability
and quality
Evaluates how a
group is
clustered or
partitioned

110. • Single Source Short Path
• All-Nodes SSP
• Parallel BFS / DFS
Pathfinding
Centrality Community
Detection
Pathfinding

111. • Strongly Connected Components
• Union Find / WCC
• Label Propagation
• Louvain
• Triangle-Count / Clustering
Coefficent
Community Detection
Pathfinding
Community
Detection
Centrality

112. • PageRank (baseline)
• Betweeness
• Closeness
• Degree
Centralities
Pathfinding
Centrality
Community
Detection

115. 1.Call as Cypher procedure
2.Pass in specification (Label, Prop, Query) and configuration
3.~.stream variant returns (a lot) of results
CALL algo.<name>.stream('Label','TYPE', {conf})
YIELD nodeId, score
4.non-stream variant writes results to graph
and returns statistics
CALL algo.<name>('Label','TYPE', {conf})
Usage

116. Pass in Cypher statement for node and relationship lists.
CALL algo.<name>(
'MATCH ... RETURN id(n)',
'MATCH (n)-->(m)
RETURN id(n) as source, id(m) as target',
{graph:'cypher'})
Cypher Projection

117. DBpedia

118. CALL algo.pageRank.stream('Page', 'Link', {iterations:5})
YIELD node, score
WITH *
ORDER BY score DESC
LIMIT 5
RETURN node.title, score
Important pages
+--------------------------------------+
| node.title | score |
+--------------------------------------+
| "United States" | 13349.2 |
| "Animal" | 6077.77 |
| "France" | 5025.61 |
| "List of sovereign states" | 4913.92 |
| "Germany" | 4662.32 |
+--------------------------------------+
5 rows 46 seconds

119. CALL algo.labelPropagation()
Largest Clusters

120. CALL algo.labelPropagation()
MATCH (n:Page)
WITH n ORDER BY n.pagerank DESC
LIMIT 1000000
WITH n.partition AS partition,
count(*) AS clusterSize,
collect(n.title) AS pages
RETURN pages[0] AS mainPage,
pages[1..10] AS otherPages
ORDER BY clusterSize DESC
LIMIT 20
Largest Clusters

121. Graph Algorithms Sandbox
neo4j.com/sandbox

122. Graph Visualization
122

126. var viz;
function draw() {
var config = {
container_id: "viz",
server_url: "bolt://localhost:7687",
server_user: "neo4j",
server_password: "sorts-swims-burglaries",
labels: {
"Character": {
"caption": "name",
"size": "pagerank",
"community": "community"
}
},
relationships: {
"INTERACTS": {
"thickness": "weight",
"caption": false
}
},
initial_cypher: "MATCH (n)-[r:INTERACTS]->(m) RETURN *"
};
viz = new NeoVis.default(config);
viz.render();
}

127. var viz;
function draw() {
var config = {
container_id: "viz",
server_url: "bolt://localhost:7687",
server_user: "neo4j",
server_password: "sorts-swims-burglaries",
labels: {
"Character": {
"caption": "name",
"size": "pagerank",
"community": "community"
}
},
relationships: {
"INTERACTS": {
"thickness": "weight",
"caption": false
}
},
initial_cypher: "MATCH (n)-[r:INTERACTS]->(m) RETURN *"
};
viz = new NeoVis.default(config);
viz.render();
}

128. var viz;
function draw() {
var config = {
container_id: "viz",
server_url: "bolt://localhost:7687",
server_user: "neo4j",
server_password: "sorts-swims-burglaries",
labels: {
"Character": {
"caption": "name",
"size": "pagerank",
"community": "community"
}
},
relationships: {
"INTERACTS": {
"thickness": "weight",
"caption": false
}
},
initial_cypher: "MATCH (n)-[r:INTERACTS]->(m) RETURN *"
};
viz = new NeoVis.default(config);
viz.render();
}

129. GraphQL

130. GraphQL is a query language for your API, and a
server-side runtime for executing queries by using a
type system you define for your data.
What is it?

131. GraphQL is a query language for your API, and a
server-side runtime for executing queries by using a
type system you define for your data.
What is it?

132. GraphQL is a query language for your API, and a
server-side runtime for executing queries by using a
type system you define for your data.
What is it?

133. GraphQL is a query language for your API, and a
server-side runtime for executing queries by using a
type system you define for your data.
What is it?
type Planet {
name: String
climate: String
}
type Character {
name: String
friends: [Character]
homeWorld: Planet
species: Species
}
type Species {
name: String
lifespan: Int
origin: Planet
}

134. Manual mapping code

136. Auto translating GraphQL → Cypher
github.com/neo4j-graphql/neo4j-graphql
github.com/neo4j-graphql/neo4j-graphql-js

137. Server Side Extension

139. dbms.unmanaged_extension_classes=org.neo4j.graphql=/graphql
dbms.security.procedures.whitelist=graphql.*
conf/neo4j.conf

140. CALL graphql.idl('
type Movie {
title: String!
released: Int
actors: [Person] @relation(name:"ACTED_IN",direction:IN)
}
type Person {
name: String!
born: Int
movies: [Movie] @relation(name:"ACTED_IN")
}'
)

141. WITH '{ Person(born: 1961) { name, born } }' as query, {} as params
CALL graphql.execute(query,params)
YIELD result
UNWIND result.Person as p
RETURN p.name, p.born

142. import requests
from requests.auth import HTTPBasicAuth
graphql_query = """
query PersonQuery($name:String!) {
Person(name:$name) {
name
born
}
}
"""
response = requests.post("http://localhost:7474/graphql/",
auth=HTTPBasicAuth("neo4j", "neo"),
headers={'content-type': 'application/json'},
json={"query": graphql_query, "variables": {"name": "Kevin Bacon"}}
)
print(response.json())

143. import requests
from requests.auth import HTTPBasicAuth
graphql_query = """
query PersonQuery($name:String!) {
Person(name:$name) {
name
born
}
}
"""
response = requests.post("http://localhost:7474/graphql/",
auth=HTTPBasicAuth("neo4j", "neo"),
headers={'content-type': 'application/json'},
json={"query": graphql_query, "variables": {"name": "Kevin Bacon"}}
)
print(response.json())

144. import requests
from requests.auth import HTTPBasicAuth
graphql_query = """
query PersonQuery($name:String!) {
Person(name:$name) {
name
born
}
}
"""
response = requests.post("http://localhost:7474/graphql/",
auth=HTTPBasicAuth("neo4j", "neo"),
headers={'content-type': 'application/json'},
json={"query": graphql_query, "variables": {"name": "Kevin Bacon"}}
)
print(response.json())

145. JavaScript Library

147. The GRAND stack

148. The GRAND stack
GraphQL
React
Apollo
Neo4j Database

149. import {neo4jgraphql} from 'neo4j-graphql-js';
const resolvers = {
Query: {
Movie(object, params, ctx, resolveInfo) {
return neo4jgraphql(object, params, ctx, resolveInfo);
}
}
};

150. dzone.com/refcardz/an-overview-of-graphql

151. How do I find out
about more cool stuff?

153. neo4j.com/tag/twin4j

154. Thank you for listening!

155. There were 28 things for
those who were counting!
devrel@neo4j.com
155

156. Agenda
Neo4j as extensible open source database
engaged community (slack, SO, partners ...)
Extensible via user defined procs/functions to add capabilities to cypher
either add new capabilities
or implement a crucial / time critical query / operation as procedure
APOC
show off some cool procs - load json (stack-overflow), graph refactoring
SO guide from students workshop
steal some queries from or SO talk / blog
Write your own procedure
Graph Algorithms
intro to graph algos (why)
PR / Clustering
Spatial (mention)
GraphQL (mention)
drop in neo4j-graphql -> show endpoint in GraphiQL
{Tag(name: "cypher") { questions { title, upvotes, owner { name, reputation } answers { text, owner { name }}}}
Mini Application?
https://neo4j.com/blog/charting-neo4j-3-0/

157. Text Slide

158. 158
Text Slide

159. Two-Column Slide
159

160. Titled Columns Slide
160

161. Blank Slide
161

162. Section Slide
162

163. Section Slide
163

164. Section Slide
164