JPA merge doesn't update table - oracle

Question

I'm facing this problem since a week, I hope someone will have a solution for me.
When I make a merge the line in database is not updated.
In the logs, I see the update which is send to Oracle
[EL Finest]: transaction: 2016-02-22 11:14:19.069--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--Merge clone with references com.leray.test.User#610b894a
[EL Finer]: transaction: 2016-02-22 11:14:19.069--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--begin unit of work flush
[EL Finest]: query: 2016-02-22 11:14:19.07--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--Execute query UpdateObjectQuery(com.leray.test.User#610b894a)
[EL Finest]: connection: 2016-02-22 11:14:19.071--ServerSession(1907961337)--Connection(307503319)--Thread(Thread[qtp1457417579-16,5,main])--Connection acquired from connection pool [default].
[EL Finer]: transaction: 2016-02-22 11:14:19.071--ClientSession(925275938)--Connection(307503319)--Thread(Thread[qtp1457417579-16,5,main])--begin transaction
[EL Fine]: sql: 2016-02-22 11:14:19.071--ClientSession(925275938)--Connection(307503319)--Thread(Thread[qtp1457417579-16,5,main])--UPDATE USER SET LIB = ? WHERE (CODE = ?)
bind => [ModifiedLib, COD1]
[EL Finer]: transaction: 2016-02-22 11:14:19.099--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--end unit of work flush
[EL Finer]: transaction: 2016-02-22 11:14:19.099--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--resume unit of work
[EL Finer]: transaction: 2016-02-22 11:14:19.099--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--begin unit of work commit
[EL Finer]: transaction: 2016-02-22 11:14:19.1--ClientSession(925275938)--Connection(307503319)--Thread(Thread[qtp1457417579-16,5,main])--commit transaction
[EL Finest]: connection: 2016-02-22 11:14:19.142--ServerSession(1907961337)--Connection(307503319)--Thread(Thread[qtp1457417579-16,5,main])--Connection released to connection pool [default].
[EL Finer]: transaction: 2016-02-22 11:14:19.143--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--end unit of work commit
[EL Finer]: transaction: 2016-02-22 11:14:19.143--UnitOfWork(2109200496)--Thread(Thread[qtp1457417579-16,5,main])--resume unit of work
The same statement in SQL Developper is working fine with the same user.
I have this issue only for one table. I didn't saw something special for this table, a trigger exist but I don't think it could explain my problem.
My code is compile whith Java 1.8 and I'm using theses version JPA and Oracle.
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>eclipselink</artifactId>
<version>2.6.2</version>
</dependency>
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>javax.persistence</artifactId>
<version>2.1.1</version>
</dependency>
<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc7</artifactId>
<version>12.1.0.2</version>
</dependency>
The object generated with Eclipse is quite simple.
package com.leray.test;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
/**
* The persistent class for the User database table.
*
*/
#Entity
#NamedQuery(name="User.findAll", query="SELECT e FROM User e")
public class User implements Serializable {
private static final long serialVersionUID = 1L;
#Id
private String code;
private String ecran;
private String lib;
private String mdp;
public User() {
}
public String getCode() {
return this.code;
}
public void setCode(String code) {
this.code = code;
}
public String getEcran() {
return this.ecran;
}
public void setEcran(String ecran) {
this.ecran = ecran;
}
public String getLib() {
return this.lib;
}
public void setLib(String lib) {
this.lib = lib;
}
public String getMdp() {
return this.mdp;
}
public void setMdp(String mdp) {
this.mdp = mdp;
}
}
My Persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="test">
<class>com.leray.test.User</class>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:oracle:thin:#server:1521:siddb"/>
<property name="javax.persistence.jdbc.user" value="****"/>
<property name="javax.persistence.jdbc.password" value="****"/>
<property name="javax.persistence.jdbc.driver" value="oracle.jdbc.OracleDriver"/>
<property name="eclipselink.logging.level" value="ALL"/>
<property name="eclipselink.logging.exceptions" value="true"/>
<property name="eclipselink.logging.session" value="true"/>
<property name="eclipselink.logging.thread" value="true"/>
<property name="eclipselink.logging.timestamp" value="true"/>
<property name="eclipselink.logging.connection" value="true"/>
<property name="eclipselink.weaving" value="false"/>
</properties>
</persistence-unit>
</persistence>
My code to call the merge
public final void miseAJour(Evuti evuti) {
em.getTransaction().begin();
em.merge(evuti);
em.flush();
em.getTransaction().commit();
}
Update 2016-02-23 : I've check with the DBA, I saw the update statement on Oracle side but he can't confirm parameters send by eclipselink. I still have no idea to solve the problem.

Answer 1

I've found the root cause and the solution.
The problem come from usage of CHAR instead of VARCHAR.
A quick sample if you want to try.
CREATE TABLE SHORT_TEST
( "CODE" CHAR(10 BYTE),
"LIB" CHAR(30 BYTE)
)
TABLESPACE "DATADBS" ;
INSERT INTO SHORT_TEST VALUES ('LIB1','COD1');
-- 1 line inserted
UPDATE SHORT_TEST SET LIB = 'LIB2' WHERE (CODE = 'COD1');
-- You get 1 line updated
-- Now, try this update which is used by eclipselink
UPDATE SHORT_TEST SET LIB = :1 WHERE (CODE = :2);
-- 0 line updated
When you use a query parameter on a char column, you have to respect the column size. In this sample, if you fill COD1 with six spaces, the query will work.
Unfortunately, I have to work with an old Oracle database and I've no right to change the structure.
By default eclipselink perform a trim on fields.
That's why for Oracle 'COD1' doesn't match with 'COD1 '.
Eclipselink offer a possibility to disabled the automatic trim.
https://wiki.eclipse.org/EclipseLink/FAQ/JPA#How_to_avoid_trimming_the_trailing_spaces_on_a_CHAR_field.3F
So, in my project, I've created a new class with this code.
package com.leray.test;
import org.eclipse.persistence.dynamic.DynamicHelper.SessionCustomizer;
import org.eclipse.persistence.sessions.Session;
public class JpaSessionCustomizer extends SessionCustomizer {
public void customize(Session session) {
session.getLogin().setShouldTrimStrings(false);
}
}
And I've added this property to persistence.xml
<property name="eclipselink.session.customizer" value="com.leray.test.JpaSessionCustomizer"/>
Now Eclipselink return datas with the end spaces and the update in Oracle is working.