Java™ How To Program (Early Objects), Tenth Edition

29.5.5 Other JPA Operations

Updating an Existing Entity

Though we don’t do so in this example, you can update an existing entity by modifying its entity object in the context of a transaction. Once the transaction is committed, the changes to the entity are saved to the database.

Deleting an Existing Entity

Though we don’t do so in this example, you can also delete an existing entity. Once you have the entity object representing the entity to remove from the database, in the context of a transaction call EntityManager method remove with the entity object to delete as an argument. When you commit the transaction the entity will no longer exist in the database.