Re: [eclipselink-users] How to use QuerySequence of eclipselink

["Andrei Ilitchev" <andrei.ilitchev@xxxxxxxxxx>]

QuerySequence is a base class for TableSequence and NativeSequence - classes 
used to support JPA TableGenarator and SequenceGenerator/Identity.

To define customized database sequence I would first look at overriding 
NativeSequence (not QuerySequence).

To assign custom sequence to entity I would use SequenceGenerator.

@Entity
public class Address {
   ...
   @GeneratedValue(generator="ADDRESS_SEQ")

   @SequenceGenerator(name="ADDRESS_SEQ", allocationSize=25)

   @Column(name="ADDRESS_ID")

   public int getId() {

       return id;

   }
...
}


Then in SessionCustomizer substitute the original sequence for the customary 
one:

public class MyCustomizer implements SessionCustomizer {

public void customize(Session session) {

   Sequence originalSequence = 
session.getPlatform().getSequence("ADDRESS_SEQ");

   session.getPlatform().addSequence(MySequence("ADDRESS_SEQ", 
originalSequence.getPreallocationSize()));

}


MyCustomizer class should be packed with the rest of the persistence unit 
(into the same jar with entity classes)
and should be listed in the properties in persistence.xml (or properies 
passed to createEntityManagerFactory):
       <properties>
           ...
           <property name="eclipselink.session.customizer" 
value="MyCustomizer"/>
       </properties>





----- Original Message ----- 
From: "Manupriya" <manupriya.sinha@xxxxxxxxx>
To: <eclipselink-users@xxxxxxxxxxx>
Sent: Wednesday, August 12, 2009 5:50 AM
Subject: [eclipselink-users] How to use QuerySequence of eclipselink


> Hi,
>
> I am trying to use QuerySequence class to create customized generator 
> using
> database sequence.
> We I am trying to add it in persistence.xml I am getting
> ClassNotFoundExcetion.
> Can anyone tell me how to use QuerySequence?
>
> Regards,
> --
> View this message in context: 
> http://www.nabble.com/How-to-use-QuerySequence-of-eclipselink-tp24931901p24931901.html
> Sent from the EclipseLink - Users mailing list archive at Nabble.com.
>
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