GraphAcademy

Intermediate Cypher Queries

Filtering Queries

Controlling Results Returned

Working with Cypher Data

Graph Traversal

Pipelining Queries

Reducing Memory

Using Parameters

OPTIONAL MATCH

Using OPTIONAL MATCH

Optionally returning rows

Here is the query you previously executed.

cypher
MATCH (m:Movie)-[:IN_GENRE]->(g:Genre)
WHERE g.name = 'Film-Noir'
MATCH (m)<-[:RATED]-(u:User)
RETURN m.title, u.name

Modify and execute this query so that the test for users who rated the movie are optional.

How many rows are returned?

  • ✓ 1152

Hint

You will prefix the MATCH clause with OPTIONAL.

Solution

You can run the following query to find the answer:

cypher
MATCH (m:Movie)-[:IN_GENRE]->(g:Genre)
WHERE g.name = 'Film-Noir'
OPTIONAL MATCH (m)<-[:RATED]-(u:User)
RETURN m.title, u.name

Once you have entered the answer, click the Try Again button below to continue.

Summary

In this challenge, you modified a query and answered a question about what was retrieved which expanded the data returned to specify an OPTIONAL MATCH.

In the next module, you will learn about controlling results returned.