We're having an issue with generated primary keys in a postgres
database. We use Seam, JbossAS, JPA, Hibernate. In a class named
Address we have a "long id" with the following annotations:
@Id
@SequenceGenerator(name = "ADDRESS_SEQ", sequenceName =
"address_id_seq", allocationSize = 1, initialValue =51)
@GeneratedValue(generator = "ADDRESS_SEQ")
private long id;
This works perfectly well, until we decided to seed the database with
an import script. It seems like Hibernate does not see the imported
addresses. The address class in Postgres has a field 'id' of type
"BigInt". But in order to have autogenerated keys, it should be
'serial'.
Our solution was to change the annotations to
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
Now, I'm happy that we found a solution, but I don't understand why
this works. Also, shouldn't Hibernate always make @GeneratedValue
fields of type 'serial'?
>From what I found googling, this seems to be a problem that only occurs
when you use Postgres.
dagdag
Christine