[JPA] Saving big numbers to the database

Question

Hi,
I have a JPA problem that I cannot solve. I try to save a large number to the database and JPA performs some strange rounding. For example, saving the number 9999999999999999.00 produces the following number in the database: 10000000000000000.00.
Actually, I'm not sure if it's JPA or the Oracle JDBC driver, but somebody rounds the number. That's bad!
Here's how to reproduce the issue:
1. Database:
create table big_num
(id  number(18),
  num number(19,2));
alter table big_num
  add constraint big_num_pk primary key (id);
create sequence big_num_seq
  start with 1
  nocache;2. Entity:
@Entity
@Table(name="BIG_NUM")
@SequenceGenerator(name="bigNumSeq", sequenceName="BIG_NUM_SEQ", allocationSize=1)
public class BigNum {
     @Id
     @Column(name="ID", nullable=false)
     @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="bigNumSeq")
     private Long id;
     @Column(name="NUM")
     private BigDecimal num;
     public Long getId() {
          return id;
     public void setId(Long id) {
          this.id = id;
     public BigDecimal getNum() {
          return num;
     public void setNum(BigDecimal num) {
          this.num = num;
}3. Code that causes the problem:
     BigNum bn = new BigNum();
     bn.setNum(new BigDecimal("9999999999999999.00"));
     em.getTransaction().begin();
     em.persist(bn);
     em.getTransaction().commit();So, the INSERT statement that iss generated to the database is:
INSERT INTO BIG_NUM (ID, NUM) VALUES (?, ?)
bind => [1, 9999999999999999.00]However, the database contains the following:
SQL> select * from big_num;
                 ID                   NUM
                  1  10000000000000000,00Can somebody tell me if it's possible to save big numbers accurately into the database? If yes, then how?
Best regards,
Bisser

Answer 1

Disabling the bind variables produces the following:
INSERT INTO BIG_NUM (ID, NUM) VALUES (2, 9999999999999999.00)The database still joyfully contains a rounded number:
SQL> select * from big_num;
                 ID                   NUM
                  2  10000000000000000,00So, no, it's not an issue with the bind variables. I need to examine the JDBC driver but could you tell me how I can find out what Oracle JDBC driver is used by JPA? Or... is it some other JDBC driver (not Oracle, that is)?
Best regards,
Bisser
P.S. We use the following version of TopLink Essentials:
TopLink, version: Oracle TopLink Essentials - 2.1 (Build b60-fcs (11/17/2008))
Edited by: bisser on Jan 28, 2009 9:25 AM