My objects are stored in the database correctly, however, when I restart the application, all tables in my database (mysql) are always cleared.
During runtime I can see that the database if filled correctly.
When I quit the application, the database still contains all objects.
After I restart however, I see that all tables are cleared from the database. At that moment the application has not done anything with hibernate. Somehow, when the sessionFactory is created, it first clears the tables....
I use the following settings for the sessionFactory (Spring):


What am I doing wrong?
What do I have to do such that hibernate will not clear the tables when my application is started?

You use

<prop key="hibernate.hbm2ddl.auto">create</prop>

in hibernate config file, which would drop database tables and create them newly whenever you restart the application.

to avoid this: once all your tables are created then remove that property from config file

Thanks, the "create" value was indeed the cause,

Now when the application is restarted, I get a "lazy initialisation" exception, saying that the session was either not open or closed....
My domain structure looks something like this: A->B->C. A contains a List<B>, "B" contains a List<C>.
I load the toplevel objects with: List<A> allA = getHibernateTemplate().loadAll(class.A);
When, somewhere later in the code B is lazy loaded (because I iterate the list, which causes the delayed loading) the exception happens.
The message of the exception is "no session or session closed". It did load parts of the structure, so there is a session I guess. I don't know why it is saying that there is no session. The parts of the structure that have been ïnstantiated looks ok.

The hibernate learning curve is steeper than I thought. It is often hard to find the reason of a failure....

Rick

Rick,

I am guessing that

you first load all A's inside the session and somehow close the session and then try to iterate A and trying to access B.

I can only guess what has happened as you dont post any of you code here

I suggest you to find the exact line of code where the B is loaded and before that line verify that you are in valid session (not closed one)

yes, hibernate's learning curve is quite steeper...:-)