The document discusses the integration of Spring Data Cassandra, highlighting its benefits such as reduced ramp-up time, annotation-based mappings, and compatibility with Spring Boot. It covers the support for basic CRUD operations, primary key definitions, and custom query capabilities using annotations and a QueryBuilder interface. Overall, it emphasizes the ease of mapping Java objects to Cassandra tables and the flexibility of query creation.

1. CASSANDRA
INTEGRATION
Spring Data

2. CASSANDRA INTRO

3. SPRING DATA
CASSANDRA

4. Rationale
• Reduces ramp up time and code required to work with
Cassandra
• Clear, annotation based mappings for java objects to
Cassandra tables
• Good fit if already using spring data / spring boot
• Minimal property based configuration

5. Features
• Uses common spring data repository pattern
• Synchronous and Asynchronous requests via the
DataStax Java Driver
• XML based CQL schema creation
• JavaConfig / XML support via properties
• QueryBuilder interface for complex query creation.

6. Annotated POJOs
• Allows easy mapping of annotated POJOs to Cassandra
tables.
@Table("users")
public class User {
@PrimaryKey("user_id")
private String userId;
@Column("first_name")
private String firstName;
@Column("last_name")
private String lastName;
private String password;

7. Spring Repository Support
• Basic Support of Spring Data Repository pattern.
• Provides CRUD operations without code, findOne, findAll,
save (upsert), delete.
• Easily extensible with custom queries.
public interface UserRepository extends CassandraRepository<User> {
@Query("select * from users where user_id = ?0")
User findByUserId(String userId);
}

8. Primary Keys
• Easily define simple, compound or composite primary
keys. Allows for narrow or wide rows.
• Simple Key example:
@PrimaryKey("user_id")
private String userId;
• Compound Key with Cluster Column Example:
@PrimaryKeyColumn(name = "eid", ordinal = 0, type = PrimaryKeyType.PARTITIONED)
private Integer eid;
@PrimaryKeyColumn(name = "day", ordinal = 1, type = PrimaryKeyType.PARTITIONED)
private Integer day;
@PrimaryKeyColumn(name = "event_id", ordinal = 2, type = PrimaryKeyType.CLUSTERED)
private UUID eventId;

9. Query Support
• No support for spring data “findBy” style queries at
present, e.g. findByNameLikeOrderBy
• Use @Query annotation for custom queries
@Query("select * from events_by_tag where eid = ?0 and tag = ?1")
List<Event> findByEidAndTag(Integer eid, String tag);

10. Query Support
• Use static BasicMapId.id() to construct primary key based
queries.
MapId id = id()
.with("eid", 1)
.with("day", 12345)
.with("eventId”, “XXXX-XXXX-XXXX”);
return eventsByDayRepository.findOne(id);

11. Or use Java Driver QueryBuilder
• Use QueryBuilder to create queries including batch and
transaction based queries.
Select select = QueryBuilder
.select()
.all()
.from(“events_by_day”)
.where(eq("eid", 1))
.and(eq("day", 12345))
.and(eq("eventId", “XXXX-XXXX-XXXX”));
return cassandraOperations
.select (select, Event.class);

12. DEMO