[HIBERNATE] property: hibernate.hbm2ddl.auto

hibernate.hbm2ddl.auto Automatically validates or exports schema DDL to the database when the SessionFactory is created. With create-drop, the database schema will be dropped when the SessionFactory is closed explicitly.

e.g. validate | update | create | create-drop

So the list of possible options are,

• validate: validate the schema, makes no changes to the database.
• update: update the schema.
• create: creates the schema, destroying previous data.
• create-drop: drop the schema at the end of the session.

These options seem intended to be developers tools and not to facilitate any production level databases, you may want to have a look at the following question; Hibernate: hbm2ddl.auto=update in production?

Source: http://stackoverflow.com/questions/438146/hibernate-hbm2ddl-auto-possible-values-and-what-they-do