Creating a new Hibernate table

Question

So I'm still pretty new to Hibernate, and I'm working on a large-ish application that already has a database with several Hibernate tables. I'm working on a new feature, which includes a new @Entity class, and I need these objects to be stored in a new table. The class is declared like this:

@Entity
@Table(name="DATA_REQUEST")
public class DataRequest {

//Some fields, nothing fancy

}

The DATA_REQUEST table does not exist, nor do I have any data to store in it yet. I started the application up, expecting that it would either create the table or crash because it doesn't exist yet. Neither of these actually happened.

So: do I need to create the table manually (easily done)? Or do I need to go somewhere else to tell Hibernate that I need this table? I've seen the hibernate.cfg.xml file, which looks like a good place to start.

Answer 1

You need to specify "create" for the "hibernate.hbm2ddl.auto" property. Read more details here. This is not recommended in production but only for testing purposes.

Answer 2

As for adding a new column to the table

• As long as it is not a not null column you don't need drop the table or restart your hibernate app

• If you do want to use the column then you need to map the column in the code/hbm file, so you will have to restart the hibernate app

• If there is no mapping present as far as hibernate is concerned the column does not exisist, If it is a not null column then underlying data base would reject inserts/updates as hibernate will not include the column in generated sql