adam-cowley

== Northwind Graph

=== Introduction

Recently, I was asked to pitch a method for providing recommendations.  Luckily, armed with the knowledge obtained from talks from Max De Marzi and [Mark Needham](https://skillsmatter.com/skillscasts/7298-modelling-a-recommendation-engine-a-worked-example) at a recent  Neo4j London Meetups, I knew this could be easily achieved with Neo4j.

The key issue with recommendation engines comes from the data.  Luckily, Neo4j comes bundled with the Northwind Graph Example.  The Northwind database is an infamous dataset containing purchase history that has been used to teach relational databases for years and was a great place to start.  You can import the Northwind database into a graph by following the ["Import Data into Neo4j"](http://neo4j.com/developer/guide-importing-data-and-etl/) post on Neo4j or type the following into Neo4j's browser at `http://localhost:7474/`

    :play northwind graph

adam-cowley

function queue(all) {
  return new Promise((resolve, reject) => {
    const output = [];

    next(all.splice(0, 1))
  
    function next(go) {
      go();
      .then(res => {
        output.push(res);

adam-cowley

CALL apoc.load.json('https://app.ticketmaster.com/discovery/v2/classifications?locale=en-us&apikey={key}') YIELD value AS json
UNWIND json._embedded.classifications as classification
MERGE (seg:Segment {ticketmaster_id: classification.segment.id, name: classification.segment.name})
WITH seg, classification
UNWIND classification.segment._embedded.genres as genre
MERGE (gen:Genre {ticketmaster_id: genre.id, name: genre.name})
MERGE (seg)-[:HAS_GENRE]->(gen)
WITH seg, gen, genre
UNWIND genre._embedded.subgenres as subgenre
MERGE (sub:SubGenre {ticketmaster_id: subgenre.id, name: subgenre.name})

adam-cowley

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>ANSIBlackColor</key>
	<data>
	YnBsaXN0MDDUAQIDBAUGFRZYJHZlcnNpb25YJG9iamVjdHNZJGFyY2hpdmVyVCR0b3AS
	AAGGoKMHCA9VJG51bGzTCQoLDA0OVU5TUkdCXE5TQ29sb3JTcGFjZVYkY2xhc3NPECUw
	LjQ4OTQ2NTYxNjMgMC41NDM3OTkwNSAwLjU2MjMyMzI0NjYAEAKAAtIQERITWiRjbGFz
	c25hbWVYJGNsYXNzZXNXTlNDb2xvcqISFFhOU09iamVjdF8QD05TS2V5ZWRBcmNoaXZl

adam-cowley

// Create an express app
const express = require('express');
const app = express();

// Tell it to use Neo4j middleware
app.use(require('./neo4j'));

// Example Route
app.get('/', (req, res) => {
    // Create Driver session

adam-cowley

const neo4j = require('neo4j-driver').v1
const driver = neo4j.driver('bolt://localhost:7687', neo4j.auth.basic('neo4j', 'neo'))

const session = driver.session()

session.run(
    'CREATE (e:Event { id: $id, title: $title, startsAt: datetime($startsAt) }) RETURN e', 
    {
        id: 2,
        title: 'Another Test Event', 

adam-cowley

node {
  diameter: 50px;
  color: #A5ABB6;
  border-color: #9AA1AC;
  border-width: 2px;
  text-color-internal: #FFFFFF;
  font-size: 10px;
}
relationship {
  color: #A5ABB6;

adam-cowley

{ status: 'success', message: 'Book updated' }
{
  ISBN: 1,
  publication: '2020-03-13',
  createdAt: '2020-03-13T17:30:20.191000000Z'
}

adam-cowley

:begin
CREATE INDEX ON :Fixture(kickoff);
CREATE CONSTRAINT ON (node:Country) ASSERT (node.id) IS UNIQUE;
CREATE CONSTRAINT ON (node:Fixture) ASSERT (node.id) IS UNIQUE;
CREATE CONSTRAINT ON (node:Group) ASSERT (node.id) IS UNIQUE;
CREATE CONSTRAINT ON (node:Player) ASSERT (node.id) IS UNIQUE;
CREATE CONSTRAINT ON (node:Stadium) ASSERT (node.name) IS UNIQUE;
CREATE CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.`UNIQUE IMPORT ID`) IS UNIQUE;
:commit
CALL db.awaitIndexes(300);

adam-cowley

// Create a graph of episodes and guests
CALL apoc.load.json('https://www.learnwithjason.dev/api/episodes')
YIELD value

// 
MERGE (e:Episode {
    id: value._id
})
ON CREATE SET 
  e.createdAt = datetime(),