Neo4j Graph Data Modeling

Mahesh Lal

• Publisher: Packt Publishing
• Year: 2015
• eBook ISBN: 9781784397302
• Edition: 1
• Topic: Computer Science
• Subtopic: Open Source Programming
• Index: Computer Science

About This Book

• Model your data as a graph using Neo4j to design databases with minimum hassle
• Discover new patterns using graphs and solve problems that are difficult to solve using any other database
• Step-by-step guide to designing a graph model with pitfalls and design choices

Who This Book Is For

If you are a developer who wants to understand the fundamentals of modeling data in Neo4j and how it can be used to model full-fledged applications, then this book is for you. Some understanding of domain modeling may be advantageous but is not essential.

What You Will Learn

• Translate a problem domain from a whiteboard to your database
• Make design decisions based on the nature of data and how it is going to be used
• Use Cypher to create and query data
• Evolve your database in stages
• Optimize the performance of your application with data design
• Design paradigms to ensure flexibility, ease of querying, and performance
• Move from an existing model to a new model without losing consistency

In Detail

Neo4j is a graph database that allows you to model your data as a graph and find solutions to complex real-world problems that are difficult to solve using any other type of database.

This book is designed to help you understand the intricacies of modeling a graph for any domain.

The book starts with an example of a graph problem and then introduces you to modeling non-graph problems using Neo4j. Concepts such as the evolution of your database, chains, access control, and recommendations are addressed, along with examples and are modeled in a graph. Throughout the book, you will discover design choices and trade-offs, and understand how and when to use them. By the end of the book, you will be able to effectively use Neo4j to model your database for efficiency and flexibility.

Neo4j Graph Data Modeling

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Table of Contents

Neo4j Graph Data Modeling

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

eBooks, discount offers, and more

Questions

1. Graphs Are Everywhere

Graphs in mathematics

The property graph model

Storage – native graph storage versus non-native graph storage

Reasons to use graph databases

What to use a graph database for

Choosing Neo4j for exploring graph databases

The structure of the book

Summary

2. Modeling Flights and Cities

Graphs are more than social

Designing a system to get a travel itinerary

Introduction to modeling flights and cities

Identifying the entities

Introduction to modeling nodes and relationships

Using Cypher to operate on Neo4j

Creating cities in Neo4j

Indices

Adding flights to Neo4j

Traversing relationships

Summary

3. Formulating an Itinerary

Creating an itinerary from flights and cities

Information and paths

Using Cypher to find a path

Business logic should lie in code

Summary

4. Modeling Bookings and Users

Building a data model for booking flights

A simple model of the bookings ecosystem

Modeling bookings in an RDBMS

Creating bookings and users in Neo4j

Creating users

Creating bookings in Neo4j

Queries to find journeys and bookings

Finding all journeys of a user

Queries to find the booking history of a user

Upcoming journeys of a user

Summary

5. Refactoring the Data Model

Capturing information about hotels at airports

Modeling airports and hotels

Extracting airport information from flights

Breaking airports out as a node

Connecting flights to airports

Delinking flights and cities

Querying the refactored data model

Reasons for not migrating using a single query

Adding hotels to airports

Fetching hotels

Summary

6. Modeling Communication Chains

Capturing traveler reviews for hotels

A model for reviews and comments

Adding reviews to Neo4j

Listing reviews for a hotel

Using reviews to find the average rating of a hotel

Adding comments to Neo4j

Considerations for modeling temporal data as chains

Summary

7. Modeling Access Control

Controlling access for content change

Modeling hierarchies

Modeling geographical regions

Adding countries and regions to Neo4j

Modeling hotel chains

Adding hotel chains to Neo4j

Modeling access control groups and employees

Adding access groups to Neo4j

Adding employees to Neo4j

Querying the data model to find what is accessible to an employee

Summary

8. Recommendations and Analysis of Historical Data

Recommending cities to travelers

Modeling categories

Creating categories in Neo4j

Cities and categories

Recommending cities based on previous travels

Recommending cities on the basis of other travelers

Recommending hotels to travelers

Recommending hotels from the same chains

Recommending hotels visited by similar travelers

Recommending hotels that match a price range

Improving recommendations

Analysis of the historical data

Querying to discover patterns

Summary

9. Wrapping Up

There is no correct model

Further reading and exploration

What to watch out for while using Neo4j

Index

Neo4j Graph Data Modeling

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: July 2015

Production reference: 1230715

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78439-344-1

www.packtpub.com

Credits

Author

Mahesh Lal

Reviewers

Patrick Baumgartner

Sonal Raj

Daniel Vaughan

Acquisition Editor

Shaon Basu

Content Development Editor

Kirti Patil

Technical Editor

Mrunmayee Patil

Copy Editor

Pranjali Chury

Project Coordinator

Nidhi Joshi

Proofreader

Safis Editing

Indexer

Mariammal Chettiyar

Production Coordinator

Conidon Miranda

Cover Work

Conidon Miranda

About the Author

Mahesh Lal is a developer who has experience with various technologies. In 2011, while working on a social network for a client, he discovered the power of graphs, specifically Neo4j. Since then, he has been working with multiple clients across various domains for modeling their data as a graph. Currently working for ThoughtWorks, India, he is trying to help his clients look at their search problems in the form of a graph.

I would like to thank my reviewers, Daniel Vaughan, Sonal Raj, and Patrick Baumgartner, for giving me valuable feedback. I am grateful to Jim Webber and Pramod Sadalge for guiding me through this journey. I am indebted to my colleagues at ThoughtWorks for believing in me. Finally, I'd like to thank my family, who always inspire me to improve.

About the Reviewers

Patrick Baumgartner works as a passionate software craftsman at 42talents and builds software with Java/JEE, Spring Framework, OSGi, NoSQL databases, and other open source technologies. Since he began working with Neo4j in 2010, he sees the whole world as one big connected graph.

He is the host of the Neo4j Zurich and the Software Craftsmanship Zurich Meetup group and is actively involved in the agile community in Switzerland.

As a Spring trainer and Neo4j master instructor, he ...

Table of contents

• Neo4j Graph Data Modeling