Implementing, Testing and Running Procedures for Neo4j

A lot of features are already included in the Neo4j graph database system but sometimes we want to extends its capabilities and implement functions and procedures by ourselves that we may reuse. In the following tutorial I will demonstrate how to implement a procedure for Neo4j, how to write and run tests using JUnit and an embedded graph database and last but not least how to setup Neo4j with Docker and our stored procedure installed in no time. ...

February 27, 2018 · 7 min · 1296 words · Micha Kops

Software Architecture Exploration and Validation with jqAssistant, Neo4j and Cypher

I have written about other software system analyzing and validation tools before but today I would like to introduce a new tool named jqAssistant that supports software architects, developers and analysts in a variety of tasks like analyzing given structures, validating architectural or quality constraints and generating reports. Therefore jqAssistant analyzes given projects or artifacts and stores the gathered information – that is enriched by a variety of existing plugin-ins – in a Neo4j graph database. ...

December 31, 2017 · 16 min · 3291 words · Micha Kops

Object Graph Mapping by Example with Neo4j OGM and Java

When integrating a Neo4j database into a Java application a developer often needs to map nodes and edges of the graph to corresponding Java classes of the domain model. Neo4j OGM eases this work and allows us to map our domain objects to the graph database using simple annotations – similar to the Java Persistence API (JPA) for relational database management systems. In the following tutorial I’d like to demonstrate how to use Neo4j OGM to build a simple train timetable planner and a permission system mapping between graph, nodes, edges and POJOs. ...

July 18, 2016 · 9 min · 1828 words · Micha Kops

A short Overview of Neo4j Indexing Strategies

When it comes to indexing in a Neo4j graph database, different options exist for a developer to create and maintain the index. In the following short examples I’d like to demonstrate different possibilities for index management. Figure 1. Simple Domain Model Dependencies Only one dependency is needed to run the following examples and start an embedded neo4j server – I’m using Gradle here to manage my dependencies but Maven, Ivy, SBT should work without a problem, too. ...

January 25, 2015 · 6 min · 1227 words · Micha Kops

Neo4j Snippets

Aggregate existing Labels MATCH (n) RETURN DISTINCT labels(n) Or unwinding label pairs MATCH (n) WITH DISTINCT labels(n) AS labels UNWIND labels AS label RETURN DISTINCT label ORDER BY label

March 1, 2010 · 1 min · 29 words · Micha Kops