EntityManager persist() method does not insert record to database

Question

I have problem with using EntityManager.persist(Object) method. Now when i get rid of other problems, by app work without Exception but object is not put in my data

Answer 1

You will need to assign id generation strategy as below:

@Entity
@Table(name ="Chain")
public class Chain implements Serializable{

@Id
@Column(name = "id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
  private Long id;
@Column(name = "date")
  private Date date;
@Column(name = "name")
  private String name;
//setters and getters
}

and in save method

  public int saveChain(Chain chain) {
        chain.setDate(new Date());
      //chain.setId((long)44);  remove this line
        Boolean a;
        em.persist(chain);

        return 222;
    }

if you assign Id, then hibernate/jpa will try to update record, which is not available, instead of inserting new record and I think will not throw exception.