neoplus

A test project to build user defined procedures to be run against a Neo4j database from Cypher.

Except for learning purposes, this repo does not contain any useful stuff.

Project built from: https://github.com/neo4j-examples/neo4j-procedure-template/

Content

Functions to compute a discount price from a full price and a discount factor. They come in different flavours:

• neoplus.discountPrice(price, discount) is a simple function that takes two (double) numbers as input, and returns the discounted price
• neoplus.discountPriceForNode(node) is called for a given node with properties "price" and "discount" and returns the discounted price
• neoplus.setDiscountPrice(node) : update the node to set the discounted price based on "price" and "discount" properties
• neoplus.discountPriceForLabel(label, priceProperty, discountProperty, defaultDiscountValue) is a slightly more complex procedure streaming the discounted price for all nodes with a given label, using configured price and discount property names, with the ability to have a default value for discount if the node property is not set.

Another type of functions are related to shortest path algorithms:

• neoplus.shortestPathLength(node1, node2): returns the length of the shortest path between node1 and node2.

Usage

0. Copy built jar to plugins directory

1. Add neoplus.* to dbms.security.procedures.unrestricted in graph settings

2. Restart graph

3. Check the procedures are there:

   CALL dbms.procedures() YIELD name, signature, description
   WITH name, signature, description WHERE name CONTAINS 'neoplus'
   RETURN name, signature, description
   

4. Call the new procedure:

   CALL neoplus.discountPriceForLabel("MyLabel", "price", "discount", 1.0) 
   YIELD newValue, nodeId 
   RETURN nodeId, newValue
   

NB ensure myProperty contains floats:

MATCH (n:MyLabel) SET n.myProperty = toFloat(n.myProperty)

Developers

Build

mvn clean package

Test

mvn test