The presentation gives a brief information about Graph Databases and its usage in today's scenario. Moving on the presentation talks about the popular Graph DB Neo4j and its Cypher Query Language i.e., used to query the graph.

1. Getting started with
Graph Databases & Neo4j
Suroor Wijdan
@wotthetech

2. Agenda for Today
● Intro to Graph Databases
● Who is using graph databases?
● What is Neo4j?
● MongoDB vs Neo4j?
● Nodes and Relationships
● Cypher Query Language
● CRUD operations in CQL
● Project Use Case
● Questions?
● Exercises

3. What is NoSQL?
● NoSQL stands for “Not Only SQL”
● Some questions which you can ask to database:
○ What is my Average Income?
○ What Items I have in his Shopping Cart?
○ How did I get into this session?
- Ask a RDBMS
- Ask a Key Value Store
- Ask a Graph

4. Intro to Graph Databases
Graph is everywhere
● Graph Databases
present a new
perspective on the
same type of data.
● Graph is the most
generic type of data
structure capable of
storing data in highly
accessible way
● Suitable for any kind of
data that is related
● Graph databases are
optimized for the
relations between
records
● a graph containing Nodes &
Relationships
● with both having Properties
● verily perfect for complex and
highly connected data
Important Quote

5. A Quote....
“A relational database may tell you how much your
customer has spent at your store”
“but”
“a graph database will tell your customers what
should they buy next”

6. Who is using Graph Databases?
● Some big names using Graph Databases:
○ Facebook - Open Graph Database
○ Google - Knowledge Graph
○ Twitter - FlockDB distributed graph Database
○ Adobe
○ Glassdoor
○ JustDial
○ CareerBuilder
○ Indiatimes
○ telenor
○ Hellwet Packard
○ T-Mobile
○ Cisco
ALL
THESE
USE

7. What is Neo4j?
● Neo4j is a robust property graph database
● Fully Transactional (ACID)
● Highly Agile
● Best suited for data which is highly
connected
● Is supremely fast when it comes to querying
connected data
● The most popular graph database in the
world
● Highly scalable, up to several billion
nodes/relationships/properties

8. What is Neo4j?
● Neo4j allows infinite depth
● Uses Cypher Query Language for querying,
also has Java and REST API’s
● Human Readable Queries
● Data Modelling in Neo4j :
○ The whole model relies on the questions we have to
ask our database
○ Very easily done, even when designing domains in
SQL we tend to make graphs on whiteboards
● Neo4j helps us derive patterns from our data

9. MongoDB vs Neo4j
MongoDB is meant for cases where you would
like to have dynamic queries on quite a size of
data.
- Not capable of handling relationships
Neo4j is best suitable in use cases where you
have complex relationships and data which is
highly connected. Neo4j can help you find
routes, social patterns, etc. from your data.
- Not Horizontally Scalable (as of now)

10. Nodes and Relationships
● A minimal graph can consist of a single node
with properties defined on it.
● A Property graph has Nodes
and Relationships with properties
defined on them.
● node ( vertex)
● relationship (edge) :- with direction
● property(attribute) :- on nodes and relationships
Lets see an example: -

11. Nodes and Relationships
Da Vinci Code
Dan Brown Manoj
Roni
The Lost Symbol
Gone with the Wind
Suspense
Thriller

12. Nodes and Relationships
Da Vinci Code
Dan Brown Manoj
Roni
The Lost Symbol
Harry Potter
Suspense
Thriller
Authored By
Read By
Friendswith
Authored By
Recommends
Belongs To
BelongsTo
Belongs
To
Release Date
Recom
m
ends
J.K Rowling Authored By
An Example of Book Store with Recommendations

13. Cypher Query Language
● Is a declarative query language for querying Neo4j
● Expressive and Human readable syntax
● Matches patterns of nodes and relationships to
extract/modify information in the graph
● With cypher, we can create, update, remove
nodes, relationships and properties
● Has an online console at http://www.neo4j.
org/console
● Has a short learning curve due to similarities with
SQL query statements

14. Cypher Query Language
Create a Node:
CREATE (n:User { fname:"Manoj", lname:“Nama” });
● User is the Label
● n is the variable for new node
● {} brackets to add properties to the node

15. Cypher Query Language
Read Properties of a Node:
MATCH (n:User)
WHERE n.fname = “Manoj”
RETURN n
● User is the Label
● n is the variable for node
● WHERE to restrict the result to our
criteria
● RETURN the properties on the node

16. Cypher Query Language
Update property on a Node:
MATCH (user:User)
WHERE user.fname = 'Manoj'
SET user.lname = ‘Mohan’
RETURN user.fname, user.lname;
● User is the Label
● Restricts search to the nodes under USER
label
● SET adds a new property to the node
● RETURN clause indicates what data to
return

17. Cypher Query Language
Delete a Node:
MATCH (user:User)
WHERE user.fname = 'Emily'
DELETE user
● User is the Label
● Restricts search to the nodes under USER
label
● DELETE clause deletes a node from graph
● RETURN clause indicates what data to
return

18. Cypher Query Language
Set a new property on a Node after creation:
MATCH (user:User)
WHERE user.name = 'Roni'
SET user.country = ‘India’
RETURN user.name, user.country;
● User is the Label
● Restricts search to the nodes under USER
label
● SET adds or updates a property on a node
● RETURN clause indicates what data to
return

19. Cypher Query Language
Find a node in CQL
START n=node(*)
WHERE HAS (n.name) AND n.name = "Roni"
RETURN n;
● START clause to begin a query
● n=node(*) to search through all nodes
● WHERE clause to constrain the results
● n.name indicates the name property must
exist
● = "Roni" compares an existing name to the
value Roni
● RETURN clause requests particular results

20. Steps to get a Neo4j server up & running
(Linux)
Run the following commands in Terminal:
● sudo bash
● wget -O - http://debian.neo4j.
org/neotechnology.gpg.key | apt-key add -
● echo 'deb http://debian.neo4j.org/repo
stable/' > /etc/apt/sources.list.d/neo4j.
list
● apt-get install neo4j
● start neo4j server, available at http:
//localhost:7474 of the machine
neo4j start

21. Neo4j Web Admin

22. References
1. Online Manual - http://docs.neo4j.org/chunked/milestone/
2. Online Cypher Console - http://console.neo4j.org
3. Cypher Cheat Sheet - http://docs.neo4j.org/refcard/1.9/
4. Graph image taken from - http://www.neo4j.org

23. THANKS!
Get in touch for any queries :
twitter: @wotthetech
github: suroorwijdan
PS: You are free to share this ppt but give due credit to the creator wherever used.