cs623_new_trends_code_demo.txt

Querying a database in Neo4j

We have two 'tables' (called 'Nodes' in Neo4j) of data: Movie, and Person.

Nodes are connected to each other through Relationships.

In this demonstration, we show some Cypher queries which can be used to query a database in Neo4j.


# finding all movies released after 2000
MATCH (m:Movie) WHERE m.released > 2000 RETURN m

# obtaining count of all movies released in or after 2005
Match (m:Movie) where m.released >= 2005 return count(m)


# finding all 'Person' entities related to 'Movie' entities via the relationship 'Directed'
# i.e. finding all people who directed a movie after 2005
MATCH (p:Person)-[d:DIRECTED]-(m:Movie) where m.released > 2005 RETURN p,d,m


# returning all instances of 'Person' and their names and birth dates
MATCH(p:Person) RETURN p.name,p.born 

# creating a new Person instance
Create (p:Person {name: 'John Doe'}) RETURN p

# finding a specific instance of Movie
MATCH (m:Movie) WHERE m.title = "Cloud Atlas" RETURN m

# finding all movies between the years 2000 and 2005 inclusive
MATCH (m:Movie) WHERE m.released >= 2000 AND m.released <=2005 RETURN m

# if 'John Doe' exists, then log current timestamp, otherwise create instance of 'John Doe' and then log current timestamp
MERGE (p:Person {name: 'John Doe'})
ON MATCH SET p.lastLoggedInAt = timestamp()
ON CREATE SET p.createdAt = timestamp()
Return p

# obtaining all Person-ActedIn-Movie relations
MATCH (p:Person)-[r:ACTED_IN]->(m:Movie) RETURN p,r,m

# obtaining all Directors of 'Cloud Atlas'
MATCH (m:Movie {title: 'Cloud Atlas'})<-[d:DIRECTED]-(p:Person) return p.name

# obtaining all Person relations related to the movie title 'Cloud Atlas'
MATCH (p:Person)-[relatedTo]-(m:Movie {title: "Cloud Atlas"}) return p.name, type(relatedTo)

# obtaining all 3rd-degree connections to 'Tom Hanks'
MATCH (p:Person {name: 'Tom Hanks'})-[*1..3]-(hollywood) return DISTINCT p, hollywood