http://disa.fi.muni.cz/vlastislav-dohnal/teaching/nosql-databases-fall-2019/
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source: Sadalage & Fowler: NoSQL Distilled, 2012
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http://db-engines.com/en/system/Neo4j
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Type Description
boolean true/false
byte 8-bit integer
short 16-bit integer
int 32-bit integer
long 64-bit integer
float 32-bit IEEE 754 floating-point number
double 64-bit IEEE 754 floating-point number
char 16-bit unsigned integers representing
Unicode characters
String sequence of Unicode characters
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$ ssh root@... -L 7474:localhost:7474
-L 7687:localhost:7687
# neo4j-community-3.1.4/bin/neo4j start
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○ /var/tmp
○ tar xvzf neo4j-community-*.tar.gz
■ module add jdk
○ ./bin/neo4j start
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○ ./bin/neo4j-shell
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○ ./bin/cypher-shell
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curl -i -X POST http://localhost:7474/db/data/node -H
"Content-Type: application/json; charset=UTF-8" --user
"neo4j" -d '{ "name": "Jan" }'
http://neo4j.com/docs/stable/rest-api.html
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http://neo4j.com/docs/stable/cypher-query-lang.html
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Created 1 node, returned 0 rows
Created 1 node, set 1 property, returned
1 row
Created 1 relationship, returned 1 row
Created 1 node, set 1 property, returned 1 row
P [Node[4]{name:"Andres"},:WORKS_AT[2]
{},Node[5]{},:WORKS_AT[3] {},Node[6]{name:"Michael"}]
1 row
Nodes created: 3
Relationships created: 2
Properties set: 2
To create just a relation ship, use
MATCH and WHERE
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Node[0]{name:"Andres",surname:"Taylor"}
1 row
Properties set: 1
Cannot delete node<3>, because it still has relationships.
Nodes deleted: 1
Relationships deleted: 1
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neo4j-community-3.1.4/bin/cypher-shell -u neo4j -p test
<movies-insert.cypher
Added 171 nodes, Created 253 relationships, Set 564
properties, Added 171 labels
stratus
localhost
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○ org.neo4j:neo4j:3.0.0
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$ unzip neo4j-excercise.zip
$ module add idea-2019.2
$ idea.sh
localhost
String PATH="some_directory";
GraphDatabaseService graphDb;
// starting a database
graphDb = new GraphDatabaseFactory().newEmbeddedDatabase(new
File(PATH));
Node firstNode, secondNode;
Relationship relationship;
// create a small graph:
firstNode = graphDb.createNode();
firstNode.setProperty( "message", "Hello, " );
secondNode = graphDb.createNode();
secondNode.setProperty( "message", "World!" );
relationship = firstNode.createRelationshipTo
(secondNode,
RelationshipType.withName("KNOWS"));
relationship.setProperty
("message", "brave Neo4j ");
// all writes (creating, deleting and updating any data)
// have to be performed in a transaction:
try (Transaction tx = graphDb.beginTx()) {
(…)
// print the result:
System.out.print(firstNode.getProperty("message"));
System.out.print(relationship.getProperty("message"));
System.out.println(secondNode.getProperty("message"));
// transaction operations
tx.success();
}
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● org.neo4j...TraversalDescription
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■ breadthFirst() depthFirst()
● .relationships()
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■ Direction.BOTH
■ Direction.INCOMING
■ Direction.OUTGOING
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■ INCLUDE_AND_CONTINUE
■ INCLUDE_AND_PRUNE
■ EXCLUDE_AND_CONTINUE
■ EXCLUDE_AND_PRUNE
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■ Evaluators.toDepth(int depth)
Evaluators.fromDepth(int depth),
■ Evaluators.excludeStartPosition()
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● Traverser
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Node admins = getNodeByName( "Admins" );
TraversalDescription desc = graphDb.traversalDescription()
.breadthFirst()
.evaluator( Evaluators.excludeStartPosition() )
.relationships(RoleRels.PART_OF, Direction.INCOMING)
.relationships(RoleRels.MEMBER_OF, Direction.INCOMING);
Traverser traverser = desc.traverse(admins);
StringBuilder output = new StringBuilder();
for ( Node node : traverser.nodes() ) {
output.append("Found: ")
.append(node.getProperty(NAME))
.append(" at depth: ")
.append(path.length()).append("\n");
}
Node jale = getNodeByName( "Jale" );
desc = graphDb.traversalDescription()
.depthFirst()
.evaluator( Evaluators.excludeStartPosition() )
.relationships(RoleRels.MEMBER_OF, Direction.OUTGOING)
.relationships(RoleRels.PART_OF, Direction.OUTGOING);
traverser = traversalDescription.traverse( jale );
Node referenceNode = getNodeByName( "Reference_Node" ) ;
desc = graphDb.traversalDescription()
.breadthFirst()
.evaluator( Evaluators.excludeStartPosition() )
.relationships(RoleRels.ROOT, Direction.INCOMING )
.relationships(RoleRels.PART_OF, Direction.INCOMING);
traverser = desc.traverse( referenceNode );
Node referenceNode = getNodeByName( "Reference_Node" ) ;
desc = graphDb.traversalDescription()
.breadthFirst()
.evaluator(Evaluators.includeWhereLastRelationshipTypeIs
(RoleRels.MEMBER_OF ));
traverser =
desc.traverse( referenceNode );
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Node ali =
graphDb.findNode(Label.label("Person"), "name", "Ali");
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■ MoviesBuild.java
■ movies-insert.cypher
localhost
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● RNDr. Irena Holubova, Ph.D. MMF UK course NDBI040:
Big Data Management and NoSQL Databases
● Neo4j http://www.neo4j.org/
● Neo4j Manual http://neo4j.org/docs/stable/
● Neo4j Download http://www.neo4j.org/download
● Cypher Query Language
http://neo4j.com/docs/stable/cypher-query-lang.html