EJB 3 Edit database record

I have problem with updating a database record using EJB and JPA. Persistence provider: `org.eclipse.persistence.jpa.PersistenceProvider` When I am creating a record I am using this method: ``` public void create(T entity) { getEntityManager().persist(entity); } ``` All is ok. Now I want to edit the the same record. For e.g. I have an entity: ``` @Entity @Table(name = "OPERATION") public class Operation implements Serializable { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "ID") private Long id; @Column(name = "OPERATION_AUTHOR") private String operationAuthor; @Column(name = "OPERATION_TYPE") private String operationType; @Column(name = "OPERATION_STATUS") private String operationStatus; @Column(name = "CREATED") @Temporal(value = TemporalType.DATE) private Date created; @Column(name = "COMPLETED") @Temporal(value = TemporalType.DATE) private Date completed; //Getters and setters } ``` For e.g. I want to update only `operationStatus`. I am creating an entity, setting to it the same record id and new `operationStatus`. For updating I am using this method: ``` public void edit(T entity) { getEntityManager().merge(entity); } ``` The problem is when I update the record the status is updated correctly but all the other columns' values are set to `null` not left as they were before. I want to update only `operationStatus` and left other values untouched. Is this possible to do this using EJB? And what should I change to make this happen?