Merge JPA is inserting instead of updating - spring

Question

Hi everyone I have this issue with merge (jpa) , first of all I read all the answers about my problem but non of theme helped me to find out a solution.
well I have a table resultat that I want to merge in my managedbean(jsf) but when I do that , I get a another row inserted
package com.journaldev.jpa.data;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Version;
#Entity
#Table(name="Resultat")
public class Resultat {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int resultatID;
#ManyToOne
#JoinColumn(name="personneID")
private Etudiant etudiant;
#ManyToOne
#JoinColumn(name="testID")
private Test test;
#Column
private boolean passer;
#Column
private int resultat;
#Temporal(TemporalType.DATE)
#Column
private Date date_passage;
public int getResultatID() {
return resultatID;
}
public void setResultatID(int resultatID) {
this.resultatID = resultatID;
}
public Etudiant getEtudiant() {
return etudiant;
}
public void setEtudiant(Etudiant etudiant) {
this.etudiant = etudiant;
}
public Test getTest() {
return test;
}
public void setTest(Test test) {
this.test = test;
}
public boolean isPasser() {
return passer;
}
public void setPasser(boolean passer) {
this.passer = passer;
}
public int getResultat() {
return resultat;
}
public void setResultat(int resultat) {
this.resultat = resultat;
}
public Date getDate_passage() {
return date_passage;
}
public void setDate_passage(Date date_passage) {
this.date_passage = date_passage;
}
}
And my service class is
public Resultat findRes(int id)
{
return this.em.find(Resultat.class,id);
}
#Transactional
public Resultat updateR(Resultat emp) {
// Save Personne
return this.em.merge(emp);
}
and this is how i use it in my managedbean
Resultat res = testService.findRes(1);
System.out.println("hahowa"+res.getResultatID());
res.setResultatID(score);
res.setPasser(true);
res= testService.updateR(res);