GraphAcademy has created a Neo4j sandbox instance for you. The graph contains a dataset of movies and people.
In this lesson, you will explore the graph and use Cypher to query it.
Nodes
The graph contains nodes labeled Movie and Person.
Neo4j includes a query language called Cypher that allows you to query the graph.
Run the following Cypher query to return the first 50 Movie nodes in the graph:
MATCH (m:Movie) RETURN m LIMIT 50You will see the Movie nodes returned as a graph.
Click on a node to see it’s properties.
Movie nodes have properties like title, released, and plot.
Try modifying the query to return Person nodes instead of Movie nodes.
Click to reveal the solution
The following query would return all the Person nodes in the graph.
The query uses Person label to filter the nodes.
The variable p represents the Person nodes in the query.
MATCH (p:Person) RETURN p LIMIT 50All nodes
You can return all the nodes by removing the LIMIT clause.
It may take longer to return all the nodes.
MATCH (m:Movie) RETURN mYou can filter the nodes returned by adding a condition to the query.
For example, you can filter Movie nodes by the title property.
MATCH (m:Movie {title: 'Toy Story'}) RETURN mRelationships
The relationships between nodes describe how people are related to movies.
For example, Person nodes have ACTED_IN and DIRECTED relationships with Movie nodes.
Run this Cypher query to return the Movie node 'Hoffa' and Person nodes with an ACTED_IN relationship to the movie:
MATCH (m:Movie {title: 'Hoffa'})<-[r:ACTED_IN]-(p:Person)
RETURN m, r, p
The movie 'Hoffa' is a Movie node with relationships to Person nodes who acted in and directed the movie.
The query doesn’t include the DIRECTED relationship, but it appears in the graph.
Neo4j will also display other relationships between the returned nodes to give a complete view.
Modify the query to return the movie 'Top Gun'.
Click to reveal the solution
The following query would return the movie node 'Top Gun' and the Person nodes with an ACTED_IN relationship to the movie.
The query uses the title property of the Movie node to filter the nodes.
The variable m represents the "Top Gun" Movie node, r is the ACTED_IN relationship, and p is the Person nodes.
MATCH (m:Movie {title: 'Top Gun'})<-[r:ACTED_IN]-(p:Person)
RETURN m, r, pView relationships
You can double-click on nodes in the graph to expand their relationships with other nodes.
Properties
Nodes have properties that describe them.
For example, Person nodes have properties like name and born, Movie nodes have properties like title and released.
Relationships in Neo4j can also have properties, the ACTED_IN relationship has a role property, storing the person’s role in the movie.
Run the following Cypher to return the movie title and person’s name who acted in the movie "Top Gun":
MATCH (m:Movie {title: 'Top Gun'})<-[r:ACTED_IN]-(p:Person)
RETURN m.title, p.nameNote how the query returns the data as a table, rather than a graph, of the movie title and person’s name.
Modify the query to return the role property of the ACTED_IN relationship.
Click to reveal the solution
The query includes r.role in the return.
The r variable represents the ACTED_IN relationship, and r.role returns the role property of the relationship.
MATCH (m:Movie {title: "Top Gun"})<-[r:ACTED_IN]-(p:Person)
RETURN m.title, p.name, r.roleYou can learn more about Cypher in the Neo4j GraphAcademy Cypher Fundamentals course.
Check your understanding
1. Nodes in the Movies graph
What node labels are used in the Movies graph?
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❏ ACTED_IN
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❏ DIRECTED
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✓ Movie
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✓ Person
Hint
The Movie graph has two labels to represent people and movies.
Hint
The Movie graph has Person and Movie node labels.
Actors and directors are represented by ACTED_IN and DIRECTED relationships.
Summary
In this lesson, you explored a Neo4j graph containing movies and people.