Spring Data Neo4J @Indexed(unique = true) not working

问题:

I'm new to Neo4J and I have, probably an easy question.

There're NodeEntitys in my application, a property (name) is annotated with @Indexed(unique = true) to achieve the uniqueness like I do in JPA with @Column(unique = true).

My problem is, that when I persist an entity with a name that already exists in my graph, it works fine anyway. But I expected some kind of exception here...?! Here' s an overview over basic my code:

@NodeEntity public abstract class BaseEntity implements Identifiable {     @GraphId     private Long entityId;     ... }  public class Role extends BaseEntity {     @Indexed(unique = true)     private String name;     ... }  public interface RoleRepository extends GraphRepository<Role> {     Role findByName(String name); }  @Service public class RoleServiceImpl extends BaseEntityServiceImpl<Role> implements  {     private RoleRepository repository;      @Override     @Transactional     public T save(final T entity) {     return getRepository().save(entity);     } } 

And this is my test:

@Test public void testNameUniqueIndex() {     final List<Role> roles = Lists.newLinkedList(service.findAll());     final String existingName = roles.get(0).getName();     Role newRole = new Role.Builder(existingName).build();     newRole = service.save(newRole); } 

That's the point where I expect something to go wrong! How can I ensure the uniqueness of a property, without checking it for myself??

P.S.: I'm using neo4j 1.8.M07, spring-data-neo4j 2.1.0.BUILD-SNAPSHOT and Spring 3.1.2.RELEASE.

回答1:

I walked into the same trap... as long as you create new entities, you will not see the exception - the last save()-action wins the battle.

Unfortunately, the DataIntegrityViolationException will be raised only in case of update an existing entity!

A detailed description of that behaviour can be found here: http://static.springsource.org/spring-data/data-graph/snapshot-site/reference/html/#d5e1035

回答2:

If you are using SDN 3.2.0+ use the failOnDuplicate attribute:

public class Role extends BaseEntity {     @Indexed(unique = true, failOnDuplicate = true)     private String name;     ... } 

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