Unit-Testing: Simple way to remove data from all tables?

trouble · **Joined:** Thu Mar 02, 2006 6:29 am **Posts:** 4

Hibernate version: 3.1.1

Hi,
I am currently Unit-Testing our Hibernate Persistence Layer. My setup() Method usually contains method calls to delete data from all tables which are affected by these tests. E.g.

Code:

      Session session = HibernateManager.getTheManager().getSession();
      Transaction transaction = session.beginTransaction();
      session.createQuery("delete from Application").executeUpdate();
      transaction.commit();

In my opinion, a method to clear all tables that are used by Hibernate would be much more convenient. A simple way to achieve something like that would be to allow wildcards in hql (like * for all Types):

Code:

session.createQuery("delete from *")

It is obvious that this does not work, at least currently. What are your ideas? How do you delete the contents of all tables?

Another way to delete everything is to drop and re-create all tables via hbm2ddl (HibernateTools), but this approach simply takes to long for unit-testing :(

Thanks in advance for all comments and help!

Kind Regards,
Matthias

LaLiLuna · **Posted:** Thu Mar 02, 2006 9:21 am

I use
simple delete from table name.
You could recreate your tables as well when your db is not large enough. Problem is that during development you might want some tables to stay (configuration tables) and other to be cleaned. I do not think that you can do this manually.

A delete cascade table definition (not in Hibernate but in the DB) would work as well.
Regards Sebastian

trouble · **Joined:** Thu Mar 02, 2006 6:29 am **Posts:** 4

Thanks for your Response!

LaLiLuna wrote:

I use
simple delete from table name.

That is what I am doing right now. The problem is that I have to maintain this "cleanup"-Method whenever I add a new persistent Class. That is why I had the idea about wildcards. An Operation like Hibernate.cleanAllTables() would be great, too :)

Quote:

You could recreate your tables as well when your db is not large enough. Problem is that during development you might want some tables to stay (configuration tables) and other to be cleaned. I do not think that you can do this manually.

Dropping all Tables and recreating them takes too long for unit-testing, there are too many tables :(

Quote:

A delete cascade table definition (not in Hibernate but in the DB) would work as well.

Unfortunately, this is not possible because the definition gets created from *.hbm.xml mapping-files when creating the SessionFactory (via hbm2ddl) before running all the tests.

Kind regards,
Matthias

LaLiLuna · **Posted:** Thu Mar 02, 2006 12:58 pm

you could read the meta data from your configuration and loop over all classes.

Best REgards Sebastian

trouble · **Joined:** Thu Mar 02, 2006 6:29 am **Posts:** 4

Thank your for that simple but very nice solution!

:)

Kind Regards,
Matthias

trouble · **Joined:** Thu Mar 02, 2006 6:29 am **Posts:** 4

I just found an even easier solution! There might be someone interested in this, so here it is:

Code:

      Session session = HibernateManager.getTheManager().getSession();
      Transaction transaction = session.beginTransaction();
      List all = session.createQuery("from java.lang.Object").list();
      Iterator it = all.iterator();
      while (it.hasNext()) {
         session.delete(it.next());
      }
      
      transaction.commit();