I am having trouble using Hibernate with MSSQL Server 2012. No matter what I do when I try to insert a value in a certain table using Hibernate I get generated id=0.
Here is the model.
#Entity
#Table(name = "tbl_ClientInfo")
public class ClientInfo {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column (name = "auto_Client_ID", unique=true, nullable=false)
private int auto_Client_ID;
...
Here is the write.
public boolean addNewClient(Client client) {
// there is a class that wraps SessionFactory as singleton
Session session = getSessionFactory().openSession();
Transaction tx = null;
Integer clientFamId; //client family info id
Integer clientId; // actual client id
try {
// create fam info first with some data - need id for ClientInfo
tx = session.beginTransaction();
ClientFam clientFam = new ClientFam();
clientFamId = (Integer) session.save(clientFam);
clientFamId = (Integer) session.getIdentifier(clientFam); // this returns the right id
session.flush();
ClientInfo clientInfo = new ClientInfo();
clientInfo.setABunchOfFields(withStuff); //multiple methods
session.save(clientInfo);
clientInfoId = (Integer) session.getIdentifier(clientInfo); // this is always 0
session.flush();
tx.commit();
} catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
return false;
} finally {
session.close();
}
return true;
}
In the database the PK auto_Client_ID is clustered, set to IDENTITY(1,1). Both ClientInfo and ClientFam records are created in the db, but hibernate returns 0. I also tried catching the value from save, but it's also 0.
I don't want to commit in-between separate insert: the transaction is when all inserts are fine (there are more after this, but I can't get to them because of this id issue yet).
The model for ClientFam is almost the same: the id field is #GeneratedValue(strategy=GenerationType.IDENTITY) as well.
I also tried specifying this for ClientInfo
#GeneratedValue(generator="increment", strategy=GenerationType.IDENTITY)
#GenericGenerator(name = "increment", strategy = "increment")
The first time I ran it it returned the correct value. However, the second time I ran it I got an error:
Cannot insert explicit value for identity column in table 'Report' when IDENTITY_INSERT is set to OFF
And that was the end of trying that. Everywhere I looked the recommendation is to use GenerationType.IDENTITY for auto incremented field in the db. That's supposed to return the right values. What might I be doing wrong?
I also tried getting the id from the ClientInfo object itself (I thought it should get written into it) after the right, but it's was also 0. Makes me think something is wrong with my ClientInfo model and/or annotations in it.
I found the problem with my situation - has nothing to do with Hibernate. There is a instead of insert trigger that wasn't returning id and hence messing up what save() returns.
This is just an educated guess, but you might want to remove the "unique=true" clause from the #Column definition. Hibernate may be handling the column as a unique constraint as opposed to a primary key.
Related
I know that there are some questions about this subject already but I think that this one is different.
Let's say I have this class:
#Entity
public class foo{
#Id
#GeneratedValue
private long id;
#Version
private long version;
private String description;
...
}
They I create some objects and persist them to a DB using JPA add().
Later, I get all from the repository using JPA all();
From that list I select one object and change the description.
Then I want to update that object in the repository using JPA merge() (see code).
The problem here is that it works the first time I try to change the description (Version value is now 2).
The second time, a OptimisticLockException is raised saying that that object was changed meanwhile.
I'm using H2 has DB in embedded mode.
MERGE CODE:
//First: persist is tried, if the object already exists, an exception is raised and then this code is executed
try {
tx = em.getTransaction();
tx.begin();
entity = em.merge(entity);
tx.commit();
} catch (PersistenceException pex) {
//Do stuff
}
What can be wrong where?
Thank you.
EDIT (more code)
//Foo b is obtained by getting all objects from db using JPA all() and then one object is selected from that list
b.changeDescription("Something new!");
//Call update method (Merge code already posted)
I would assume that you are changing elements in the list from different clients or different threads. This is what causes an OptimisticLockException.
One thread, in it's own EntityManager, reads the Foo object and gets a #Version at the time of the read.
// select and update AnyEntity
EntityManager em1 = emf.createEntityManager();
EntityTransaction tx1 = em1.getTransaction();
tx1.begin();
AnyEntity firstEntity = em1.createQuery("select a from AnyEntity a", AnyEntity.class).getSingleResult();
firstEntity.setName("name1");
em1.merge(firstEntity);
Another client reads and updates the Foo object at the same time, before the first client has committed its changes to the database:
// select and update AnyEntity from a different EntityManager from a different thread or client
EntityManager em2 = emf.createEntityManager();
EntityTransaction tx2 = em2.getTransaction();
tx2.begin();
AnyEntity secondEntity = em2.createQuery("select a from AnyEntity a", AnyEntity.class).getSingleResult();
secondEntity.setName("name2");
em2.merge(secondEntity);
Now the first client commits its changes to the database:
// commit first change while second change still pending
tx1.commit();
em1.close();
And the second client gets an OptimisticLockException when it updates its changes:
// OptimisticLockException thrown here means that a change happened while AnyEntity was still "checked out"
try {
tx2.commit();
em2.close();
} catch (RollbackException ex ) {
Throwable cause = ex.getCause();
if (cause != null && cause instanceof OptimisticLockException) {
System.out.println("Someone already changed AnyEntity.");
} else {
throw ex;
}
}
Reference: Java - JPA - #Version annotation
Are you properly initialising the version field?
If not, it is not supposed to work with null, try adding a default value to it:
#Version
private Long version = 0L;
Here are a post which explains perfectly when OptimisticLockException is thrown.
Also, just for future reference, you can make JPA avoid this in-memory validation of entities when you are updating them but want to change in DB side just in the end of this transaction using detach method on EntityManager:
em.detach(employee);
Entity with id autogenerated from oracle trigger sequence.
#Entity
#Table(name = "REPORT", schema = "WEBPORTAL")
public class Report {
private Integer id;
....
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator="report_sequence")
#SequenceGenerator(name="report_sequence", sequenceName = "report_id_seq")
#Column(name="REPORT_ID", unique = true, nullable = false)
public Integer getId() {
return id;
}
....
}
Service
#Service("reportService")
public class ReportServiceImpl implements ReportService {
....
#Transactional(readOnly=false)
public void saveOrUpdate(Report report) {
reportDAO.saveOrUpdate(report);
}
}
DAO
#Repository
public class ReportDAOImpl implements ReportDAO {
....
#Override
public Report save(Report report) {
try {
Session session = sessionFactory.getCurrentSession();
session.save(report);
} catch (Exception e) {
logger.error("error", e);
}
return report;
}
}
And When I call service's saveOrUpdate and then try to reach id of entity I get different value than persisted in database. Values on database with autogeneration all is ok. Any suggestions?
reportService.saveOrUpdate(report);
System.out.println(report.getId());
prints: 4150
but saved id in database is: 84
NOTE: My purpose to get Id comes from that I wanted to save childs with cascade. But foreign key on child was different in database(the values of id that I get with getId()).
And Id generated in database is incremented by 2. EX: 80, 82, 84.
UPDATE:
Oracle trigger for sequence generation
CREATE OR REPLACE TRIGGER REPORT_ID_TRIG
BEFORE INSERT ON WEBPORTAL.REPORT
FOR EACH ROW
BEGIN
SELECT report_id_seq.NEXTVAL
INTO :new.report_id
FROM dual;
END;
ANSWER: Trigger should check if id is null
CREATE OR REPLACE TRIGGER REPORT_ID_TRIG
BEFORE INSERT ON WEBPORTAL.REPORT
FOR EACH ROW
WHEN (new.report_id is null)
BEGIN
SELECT report_id_seq.NEXTVAL
INTO :new.report_id
FROM dual;
END;
DESCRIPTION:
#GeneratedValue is not just a sequence generator. It's bit of HiLo algorithm.When it first requests id from database it multiplies it with 50(it can differ) and next 50 new entities will be given ids consequently, and than next request to database. This is to decrease request to database.
The numbers that I get from java was right numbers that should be saved on report.
Without id null value check Hibernate firstly requested for id from database and sequence.nextval called. When hibernate was persisting it(completing transaction) the database called sequence.next second time and set that value to database. So on ReportDetails there was true id value of report and on the Report id it was id set from database.
The problem is that two separate mechanisms are in place to generate the key:
one at Hibernate level which is to call a sequence and use the value to populate an Id column and send it to the database as the insert key
and another mechanism at the database that Hibernate does not know about: the column is incremented via a trigger.
Hibernate thinks that the insert was made with the value of the sequence, but in the database something else occurred. The simplest solution would probably be to remove the trigger mechanism, and let Hibernate populate the key based on the sequence only.
Another Solution:
check your trigger definition that should be in this format
(WHEN (new.report_id is null) ) is important.
CREATE OR REPLACE TRIGGER TRIGGER_NAME
BEFORE INSERT ON TABLE_NAME
FOR EACH ROW
WHEN (new.id is null)
BEGIN
SELECT SEQUENCE_NAME.NEXTVAL
INTO :new.id
FROM dual;
END
I know there are many similar questions about this trouble but nothing works for me.
I have #ManyToOne relationship between Aim and User.
#ManyToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "user_id", nullable = false, updatable = false)
private User user;
and
#OneToMany(fetch = FetchType.LAZY, mappedBy = "user")
private Collection<Aim> userAims;
respectively.
#Override
#Transactional(propagation = Propagation.REQUIRED)
#PreAuthorize("isAuthenticated() and principal.user.isEnabled() == true")
public Aim findById(String aimId) throws NumberFormatException, EntityNotFoundException {
Aim aim = null;
try {
aim = aimRepository.findOne(Long.parseLong(aimId));
} catch (NumberFormatException e) {
throw new InvalidDataAccessApiUsageException(e.getMessage(), e);
}
if (aim == null) throw new EntityNotFoundException("Aim with id: " + aimId + " not found!");
return aim;
}
#OneToMany associations work fine with lazy fetching. Method isn't nested to another #Transactional method so #Transactional works fine.
So the record exists.
Classes User and Aim aren't final and implement
Serializable
Some sources advice to put annotations on getters. It also doesn't
work.
#Fetch(FetchMode.SELECT) the same situation =\
Query via Hibernate results the same, but HQL query with left join
fetch works fine
My FK is ON UPDATE CASCADE ON INSERT CASCADE
optional = false also tried...
Pay attention that I haven't the LazyInitException
Thanks in advance!
I'm guessing from the code in your findById method, and by the reference to "lazy initialization not working" in the title, that you are wanting to find an Aim object by it's numeric Id, along with the associated User object.
In order to do this with lazy-loading, you need to 'get' the associated object, and (most importantly) you need to 'get' one of the associated entity's fields.
So the code inside the try block should be:
aim = aimRepository.findOne(Long.parseLong(aimId));
if (aim != null && aim.getUser() != null) {
aim.getUser().getUserId(); // doesn't need to be assigned to anything
}
Alternatively, if you have a logger available you can use the userId in a debug or trace log message:
if (aim != null && aim.getUser() != null) {
logger.debug("Lazy-loaded User " + aim.getUser().getUserId());
}
This has the added benefit that you can debug how things are lazy-loaded.
By the way, we found out the hard way that making a find routine throw an Exception when it doesn't find something is a bad idea. This is because you might want to use the find routine to find out if an Entity does NOT exist. If that is happening within a transaction, your exception may trigger an unwanted rollback (unless you specifically ignore it). Better to return null and check for that instead of using a try ... catch.
This syntax does not produce unique values across different Fetch Groups:
#Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private long id;
So I've written the method below to simulate generating a database sequence for my Order model. But what I'm not sure about is what the transactional state needs to be configured as here (isolation level / nontransactional read / nontransactional write / optimistic / etc.):
public long getNextId()
{
PersistenceManager pm = this.getPm();
Transaction tx = pm.currentTransaction();
tx.begin();
long nextId = 0;
Query query = pm.newQuery("select id from orders order by id desc");
query.setRange(0, 1);
try
{
List<Order> results = (List<Order>) query.execute();
if (results.iterator().hasNext())
{
for (Order r : results)
{
nextId = r.getId() + 1;
}
}
else
{
return 0;
}
}
catch (Exception e)
{
return 0;
}
tx.commit();
return nextId;
}
Does the scope of the transaction need to be broader than just this method? In other words, should it also include the insert action for the new Order?
I want to make sure that no two Orders that I insert can have the same id value across the entire application.
IDs generated with IdGeneratorStrategy.SEQUENCE are unique for all entities with the same parent. If your entities are root entities (Eg, no parent), then they will all get unique IDs. What is your use case where you have child entities, but need a unique ID across all of them?
Whats wrong with IdGeneratorStrategy.SEQUENCE ? since GAE/J claims to support it
I want the first to be generated:
#Id
#Column(name = "PRODUCT_ID", unique = true, nullable = false, precision = 12,
scale = 0)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "PROD_GEN")
#BusinessKey
public Long getAId() {
return this.aId;
}
I want the bId to be initially exactly as the aId. One approach is to insert the entity, then get the aId generated by the DB (2nd query) and then update the entity, setting the bId to be equal to aId (3rd query). Is there a way to get the bId to get the same generated value as aId?
Note that afterwards, I want to be able to update bId from my gui.
If the solution is JPA, even better.
Choose your poison:
Option #1
you could annotate bId as org.hibernate.annotations.Generated and use a database trigger on insert (I'm assuming the nextval has already been assigned to AID so we'll assign the curval to BID):
CREATE OR REPLACE TRIGGER "MY_TRIGGER"
before insert on "MYENTITY"
for each row
begin
select "MYENTITY_SEQ".curval into :NEW.BID from dual;
end;
I'm not a big fan of triggers and things that happen behind the scene but this seems to be the easiest option (not the best one for portability though).
Option #2
Create a new entity, persist it, flush the entity manager to get the id assigned, set the aId on bId, merge the entity.
em.getTransaction().begin();
MyEntity e = new MyEntity();
...
em.persist(e);
em.flush();
e.setBId(e.getAId());
em.merge(e);
...
em.getTransaction().commit();
Ugly, but it works.
Option #3
Use callback annotations to set the bId in-memory (until it gets written to the database):
#PostPersist
#PostLoad
public void initialiazeBId() {
if (this.bId == null) {
this.bId = aId;
}
}
This should work if you don't need the id to be written on insert (but in that case, see Option #4).
Option #4
You could actually add some logic in the getter of bId instead of using callbacks:
public Long getBId() {
if (this.bId == null) {
return this.aId;
}
return this.bId;
}
Again, this will work if you don't need the id to be persisted in the database on insert.
If you use JPA, after inserting the new A the id should be set to the generated value, i tought (maybe it depends on which jpa provider you use), so no 2nd query needed. then set bld to ald value in your DAO?