Unnecessary Update - Entity not changed, but update statement exectuted

[Norbert Rieger <nr...@lplusr.de>]

Hello,

when looking at my openEjb log file, I can see some updates I've never done
:-)

It looks like the entity is updated with the same values as stored already
in the database, the entity object was not modified.

This is what I do:

	Bti ent ;

	tx.begin () ;                
		ent = em.find (Bti.class, 200L) ;
	tx.commit () ;

and here's the result from the log:


11437  PersistencePU  TRACE  [main] openjpa.jdbc.SQL - <t 15431769, conn
13330996> executing prepstmnt 31536808 SELECT t0.genDate, t0.modDate,
t0.bt_pkey, t0.descr, t0.fifo_order, t0.fifo_window, t0.ident, t0.type FROM
Bti t0 WHERE t0.pkey = ? [params=(long) 200]
...

Why is this update done ?
------------------==>
32719  PersistencePU  TRACE  [main] openjpa.jdbc.SQL - <t 15431769, conn
816382> executing prepstmnt 2665317 UPDATE Bti SET genDate = ?, modDate = ?,
bt_pkey = ?, descr = ?, fifo_order = ?, fifo_window = ?, ident = ?, type = ?
WHERE pkey = ? [params=(Timestamp) 2009-02-13 09:47:18.828, (Timestamp)
2009-02-13 09:59:06.375, (null) null, (null) null, (String) DESC, (int)
4711, (String) BTI-1, (String) TIMESTAMP, (long) 200]
------------------<==


Can someone point me to what I'm doing wrong ?

Thanks a lot for your help

Norbert




Here's the entity definition:


@NamedQueries
({
    @NamedQuery(name="Bti.findAll",       query="SELECT o FROM Bti o WHERE
o.btPkey = :btPkey"),
    @NamedQuery(name="Bti.findByIdent",   query="SELECT o FROM Bti o WHERE
o.btPkey = :btPkey and o.ident = :ident")
})
@Entity
@Table(uniqueConstraints=@UniqueConstraint(columnNames={"bt_pkey",
"ident"}))
public class Bti extends EntityBaseTimestamps implements Serializable 
{
    @Id
    @TableGenerator (name="PK_GEN_BTI",
                     table="PK_GEN",
                     pkColumnName="PK_IDENT",
                     pkColumnValue="BTI.PKEY",
                     valueColumnName="PK_VALUE")
    @GeneratedValue (strategy=GenerationType.TABLE,
                     generator="PK_GEN_BTI")
    private Long pkey;
    
    private String ident ;
    
    @Column(name="bt_pkey")
    private Long btPkey ;
    
    private Long descr ;
    
    @Enumerated(EnumType.STRING)
    @Column(name="type",length=32)
    BtiType_e type ;
    
    @Enumerated(EnumType.STRING)
    @Column(name="fifo_order",length=32)
    BtiFiFoOrder_e fifoOrder ;
    
    @Column(name="fifo_window")
    Integer fifoWindow ;
    
    public Bti() 
    {
    }
}

EntityBaseTimestamps is a @MappedSuperclass holding modDate and genDate
fields.