I am facing an issue(org.springframework.orm.hibernate3.HibernateSystemException: No Dialect mapping for JDBC type: -9).
I have upgraded my application from ojdbc6.jar to ojdbd7.c for Oracle 12c Container Database.
Hibernate version is 3.5.6

For me issue is fixed by casting a nvarchar datatype to varchar2. But i don't want to go by this approach.

Please help in understating why nvarchar is not working with ojdbc7.jar. What would be the best fix for this issue.

Oracle9iDialect or later ones map NVARCHAR to nvarchar2. What version of Oracle dialect are you using?

Thanks for the reply.

Datatype in database is NVARCHAR2.

I am using Oracle10gDialect.
For Oracle12cDialect i need to upgrade Hibernate on 4.4 as on previous version it is not available.

Can you replicate the issue with Hibernate 5? Maybe it was some issue that got fixed.

For Hibernate 4/5, we need to change our code drastically.
As we are using some classes which is not present in Hibernate 4, like BtmTransactionManagerLookup, Ejb3Configuration.getHibernateConfiguration() etc

Is there any link, for list of classes which were available in Hibernate 3.5.6 and not present in Hibernate 4/5 ?

You can use the Hibernate Migration guides.Unfortunately, neither Hibernate 3.x and 4.x are supported, so only if it affects Hibernate 5.x, the issue is going to be fixed.

Can you please tell me more about that nvarchar issue, I want to know the root cause of this issue.
And what is not fixed in 3.x/4.x and fixed in 5.x?

Unfortunately, I don't know of any such issue, so you need to replicate it with the Hibernate 5 test cases and if there is such an issue, you should open a bug on JIRA.

One more query, which dailect I should use with Oracle 12c pluggable database.
I am able to up the application with 10gdialect.

You can use both 10 and 12 OracleDialects. With 10, you'll have less features.