Hi all,
I am trying to use JPA entity class to insert and update records in to
Java Durby Database and i am using @Version.
I m using NetBeans 6.1,Java Durby as a database
following is my table in database :
create table STUDENT
(
RNO int primary key,
FNAME varchar(20) ,
LNAME varchar(20),
M1 int,
M2 int,
AVEG double,
RES varchar(20),
VERSION int
)
Following is my Entity calass :
I am using Oracle Toplink as Persistance Provider :
Following is my Persistance
Unit's persistence.xml file :
Following is a Client code i am using to Insert a Record :
The above code works completely fine and it inserts a record in to database with VERSION = 1
but wen i try to update the same record by following code i m getting an error :
Update code :
when i run the above program i ger following error in output window :
While updating the version should become 2 but instead i get the above error.
I m getting the same problem while using the same entity class in
EJB also with glassfish server & Durby DB
I have no idea from where this java.lang.NullPointerException is coming from
IF I REMOVE @Version FROM ENTITY CLASS THE CODE WORKS FINE it then updates the record.
please let me know if i have made any mistakes .
Thanks