Contact.java
@NamedQueries(value = @NamedQuery(name = "findContactByMail", query = "SELECT c FROM Contact c WHERE c.mail= :mail AND c.location= :location"))
@Entity
@Table(name = "CONTACT")
public class Contact {
@Id
@Column(name = "ID")
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@Column(name = "MAIL")
private String mail;
@Column(name = "LOCATION")
private String location;
....
}
Client.java
@PersistenceContext
private EntityManager entityManager;
public Contact findContactByMail(String mail, String location){
TypedQuery findContactByMail = entityManager.createNamedQuery("findContactByMail",Contact.class);
findContactByMail.setParameter("mail", mail);
findContactByMail.setParameter("location", location);
try {
return findContactByMail.getSingleResult();
}
catch (NoResultException e) {
return null;
}
}
....
}