Hi!
hibernate.hbm2ddl.auto have 4 possibilities :
eg. validate | update | create | create-drop

With create-drop, the database schema will be dropped when the SessionFactory is closed explicitly.

With create only drops and creates the schema when the SessionFactory is created.

With update setting is for automatic updates of schema for schema evolution. (what does it means?)

What the validate do?

from Hibernate in Action: "The DDL generated by hbm2ddl will always drop all tables and regenerate them; this is especially useful in development."
and if i dont want them to be droped?

thks!

It means that Hibernate tries to keep DB schema up-to-date, i.e. creating and updating necessary objects in the DB.


Use 'update'


Better yet: manage database schema yourself (with appropriate DB centric tools and scripts), especially for production.

First of all, thank you for your reply!
actually the database is already ready with all the tables and objects there... there is a system working on this databese (production), and now i am "translating" it to open source tecnology. So, ill not create anything new in this databese, only use it. So, as i have understood, i even dont need to use any of these 4 option, am i right?

but, just to know, do you know what the validate do?

thks!

Yes, you simply do not need to use the hbm2ddl.auto option at all.
It will also significantly speed up the startup time for your application