posted 10 years ago
I assume you are wanting to create your tables based on your mappings (for development only)
If you are using hibernate as your persistence provider have a look at the hibernate.hbm2ddl.auto property.
As far as JPA is concerned you can define your metadata in your annotations as well for example:
This will generate a unique constraint on the column when the tables are generated.
Specifies the nullable attribute for the column
Specifies the length on the column
Specifies the precision and scale.
You get the idea. If there is something in particular you were looking for you will have to let us know.