Executing queries

How do you execute a Cypher statement and access the results?

Execute the Cypher statement

Select the correct method to create an executable Cypher statement.

java

final String cypher = """
    MATCH (m:Movie {title: $title})<-[:ACTED_IN]-(p)
    RETURN p.name AS actor
    """;
final String title = "Toy Story";

var result = driver./*select:executableQuery(*/
    cypher
    )
    .withParameters(Map.of("title", title))
    .execute();

❏ cypher(
✓ executableQuery(
❏ execute(
❏ verifyConnectivity(

Hint

The method to execute a Cypher query with the driver is the same one you used in the previous lesson - it starts with executable.

Solution

The correct answer is executableQuery(). This method creates an executable Cypher query which can be executed.

Java

var result = driver.executableQuery(cypher).execute();

Specify database for query

You want to run the query on the "movies" database. Select the correct option to specify the database.

java

final String cypher = """
    MATCH (m:Movie {title: $title})<-[:ACTED_IN]-(p)
    RETURN p.name AS actor
    """;
final String title = "Toy Story";

var result = driver.executableQuery(cypher)
    .withParameters(Map.of("title", title))
    .withConfig(/*select:QueryConfig.builder().withDatabase("movies").build()*/)
    .execute();

✓ QueryConfig.builder().withDatabase("movies").build()
❏ SessionConfig.builder().withDatabase("movies").build()
❏ DatabaseConfig.builder().withDatabase("movies").build()
❏ withDatabase("movies")

Hint

Use the configuration class that works with executableQuery() to specify which database to query.

Solution

The correct answer is QueryConfig.builder().withDatabase("movies").build().

Java

import org.neo4j.driver.QueryConfig;

var result = driver.executableQuery(cypher)
    .withParameters(Map.of("title", title))
    .withConfig(QueryConfig.builder().withDatabase("movies").build())
    .execute();

The QueryConfig class is used to configure query execution options, including the database name. Use QueryConfig.builder().withDatabase() to specify which database to query when executing a Cypher statement with executableQuery().

Print the actor names

Select the correct method to print the name of each actor.

Java

final String cypher = """
    MATCH (m:Movie {title: $title})<-[:ACTED_IN]-(p)
    RETURN p.name AS actor
    """;
final String title = "Toy Story";

var result = driver.executableQuery(
    cypher
    )
    .withParameters(Map.of("title", title))
    .execute();

var records = result.records();
records.forEach(r -> {
        System.out.println(
            /*select:r.get("actor")*/
        );
    });

❏ records.get("p.name")
❏ records.get("actor")
❏ r.get("p.name")
✓ r.get("actor")

Hint

Review the RETURN clause in the Cypher statement.

Java

cypher = """
MATCH (m:Movie {title: $title})<-[:ACTED_IN]-(p)
RETURN p.name AS actor
"""

Solution

The name property of the p node is aliased as actor in the RETURN clause.

The get method of the Record object takes the alias as an argument.

Java

records.forEach(r -> {
    System.out.println(
        r.get("actor")
    );
});

Lesson summary

Nice work! You learned how to execute a Cypher statement and access the results.

In the next lesson, you will review how to transform the results.

Using Neo4j with Java

The Driver

Handling results

Best practices

Executing queries

Execute the Cypher statement

Specify database for query

Print the actor names

Lesson summary

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