Alter database design with JPA

Question

I am working on database with JPA and i am curios about altering the database design. Lets say i have a table and i want to add/remove a column in that table.

I have tried with re-deploying technique but it did not work for me. I am using JPA 2.0

So, just want to know is there any standard way to alter database tables or manually add/remove table's design? Also is it possible to change the primary key of table ?

Any help will be highly appreciated.

Thanks :)

Answer 1

For non-production DBs you can use the persistence.xml properties to either create, drop-create or just update the existing db schema (example for Hibernate):

<persistence ...>
  <persistence-unit ...>
    <property name="hibernate.hbm2ddl.auto" value="create-drop" />

for EclipseLink, the property name is different and so are the available options:

<property name="eclipselink.ddl-generation" value="create-tables"/>
<property name="eclipselink.ddl-generation.output-mode" value="database"/>

For production DBs however I would stick to manual changes as you have to be very careful about the details and the timing.