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.nameModify 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.nameOnce 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.