Hey,

I am trying to migrate an application from GF that uses Toplin as JPA to Jboss with Hibernate,


I'm still having a confusion of how to generate IDs as generic as possible,

Usually my app is deployed with Oracle 9/10 or Mysql DBs and I'd like to have my application be as generic as possible,

I tried just to use '@Id @GeneratedValue' annotations but with Oracle it just didn't work. so my entities ID get method looked like:

@Id @GeneratedValue //JB
 @Column(name="MY_ID")
 public Long getMyId() {
 return myId;
 }

So, with Toplink, I solved it by using GenerateSequences, which worked fine for Mysql too.

It looked like:

@Id
@SequenceGenerator(name="MYTABLE_GEN",sequenceName="MYTABLE_SEQ", allocationSize=1)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator="MYTABLE_GEN")
 @Column(name="MY_ID")
 public Long getMyId() {
 return myId;
 }

When I tried to deploy my application with Jboss, I got the following exception:

Caused by: org.hibernate.MappingException: could not instantiate id generator
 at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:98)
 at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:152)
 at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:192)
 at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1294)
 at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:713)
 ... 99 more
Caused by: org.hibernate.MappingException: Dialect does not support sequences
 at org.hibernate.dialect.Dialect.getSequenceNextValString(Dialect.java:595)
 at org.hibernate.id.SequenceGenerator.configure(SequenceGenerator.java:65)
 at org.hibernate.id.SequenceHiLoGenerator.configure(SequenceHiLoGenerator.java:43)
 at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:94)
 ... 103 more

What am I doing wrong? and most important, what's the best practice of generating regular long IDs in order to support most of the DB vendors? (especially Mysql/Oracle)

Thanks,

Asaf.