Database default field not retrieved when using #Transactional - spring

Question

I have the following simple entity FileRegistry :
#Getter
#Setter
#Entity
#ToString
#Table(name = "file_store")
public class FileRegistry {
#Id
private String name;
/**
* Creation timestamp of the registry
* This value is automatically set by database, so setter method
* has been disabled
*/
#Setter(AccessLevel.NONE)
#Column(insertable = false, updatable = false)
private LocalDateTime creationDate;
}
The following FileRepository DAO:
#Repository
public interface FileRepository extends JpaRepository<FileRegistry, String> { }
and the following Spring Boot test :
#SpringBootTest(classes=PersistTestConfig.class, properties = { "spring.config.name=application,db"})
#ActiveProfiles("test")
#Transactional
public class FileRepositoryTest {
#Autowired
FileRepository fileRepository;
#Test
void insertFileTest() {
assertNotNull(fileRepository, "Error initializing File repository");
// Check registry before insertion
List<FileRegistry> allFiles = fileRepository.findAll();
assertNotNull(allFiles, "Error retrieving files from registry");
assertThat(allFiles.size(), is(0));
// Insert file
FileRegistry fileRegistry = new FileRegistry();
fileRegistry.setName("Test");
fileRepository.save(fileRegistry);
// Check that the insertion was successful
allFiles = fileRepository.findAll();
assertNotNull(allFiles, "Error retrieving files from registry");
assertThat(allFiles.size(), is(1));
assertEquals("File registry name mismatch", "Test", allFiles.get(0).getName());
System.out.println(allFiles.get(0));
}
}
Persistence configuration class defined as follows :
#Configuration
#EnableAutoConfiguration
#EnableTransactionManagement
#EnableJpaRepositories
public class PersistTestConfig {
}
The table file_store defined in H2 as :
CREATE TABLE file_store (name VARCHAR NOT NULL, creation_date TIMESTAMP(3) DEFAULT NOW() NOT NULL, CONSTRAINT file_store_pk PRIMARY KEY (name));
Everything works fine except that when I use #Transactional at test level (mainly to benefit from rollbacks i.e. db cleanup on each test) a null value is fetched for the creationDate field :
FileRegistry(name=Test, creationDate=null)
When I remove #Transactional from the test class, the fetched value contains the date as computed by H2 :
FileRegistry(name=Test, creationDate=2019-03-07T17:08:13.392)
I've tried to flush and merge manually the instance to no avail. To be honest, right now I'm a little bit lost on how #Transactional really works, in fact reading the docs and inspecting the code, the underlying JpaRepository implementation (SimpleJpaRepository) is annotated as #Transactional(readOnly = true).
A little help on this subject would be very appreciated.

Answer 1

Ok, figured it out.
Simply issuing a refresh entityManager.refresh(allFiles.get(0)); solves the issue.
I tested also using Hibernate's #Generated(INSERT) specific annotation in the entity creationDate field and it also worked fine.
By the way I've eventually decided to drop this thing in favor of using Spring Data's JpaAuditing features and annotating the field with #CreatedDate annotation to fill the value instead of relying on DB date (by the way, production-wise, you probably shouldn't rely on DB time). To me this is feels more, let's say, "correct" and springy way of doing things.