In a web application I want to use a sequence in the DB to generate unique, incrementing ids I need for an external interface.

Can I do it without using native SQL (in Hibernate 2.1)?

The closest I found was:
Dialect.getSequenceNextValString ( "my_sequnce_name" )
But I found no way to find out the Dialect of the running session.

Actually I need something like:
Serializable Session.getSequenceNextVal ( "my_sequnce_name" );

Use the sequence generator and you don't need to think about it since it will just work.
[url]http://www.hibernate.org/hib_docs/reference/en/html/mapping.html#mapping-declaration-id-sequences
[/url]

Sorry i missed the 'external interface'. In this case use native SQL interface where you may hide the impl in a support package to get the clean method call. Alternative, you could use a direct JDBC call.


Note: Keep the Configuration object around and it can tell you the dialect being used.

during setup:

Configuration config = new Configuration ().configure ( "/config/hibernate.cfg.xml" );

SessionFactory sf = config.buildSessionFactory ();
DatabaseSession.setSessionFactory ( sf );

Dialect dialect = Dialect.getDialect ( config.getProperties () );
DatabaseSession.setDialect ( dialect );

later usage:

Dialect dialect = DatabaseSession.getDialect ();
String query = dialect.getSequenceNextValString ( "my_sequence" );

PreparedStatement ps = DatabaseSession.getSession ().connection ().prepareStatement ( query );


Seems to work, but I see ample room for simplification by the Hibernate team :-)