Using @GeneratedValue with Firebird and JPA (EclipseLink)

If you need to manage generated values in a Java application that uses JPA (Java Persistence API) and FirebirdSQL as database you can use @GeneratedValue annotation according to EclipseLink.

All you need to do is follow these steps:

1. Create your FIREBIRD generator

-- create your generator
CREATE GENERATOR GEN_ORDER;
SET GENERATOR GEN_ORDER TO 0;

If you are using FirebirdSQL 2.0 you can use CREATE SEQUENCE http://www.firebirdsql.org/refdocs/langrefupd20-create-seq.html

-- For Firebird 2.x
CREATE SEQUENCE GEN_ORDER;
ALTER SEQUENCE GEN_ORDER RESTART WITH 0;

2.Use @SequenceGenerator and   @GeneratedValue in your Entity class

• Specify a name for your Sequence

     @SequenceGenerator( name = "YOUR_SEQUENCE_NAME", sequenceName = "YOUR_GENERATOR", allocationSize = 1 )

• Use GeneratedValue and assign previous name to generator property

 @GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "YOUR_SEQUENCE_NAME" )   
 
For example to use Firebird generator defined in Step 1 use this lines:

    @SequenceGenerator( name = "ORDER_SEQUENCE", sequenceName = "GEN_ORDER", allocationSize = 1 ) 
    @GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "ORDER_SEQUENCE" )     

Finally your java class looks like this:

I hope this can help you.