Generated value exception java jpa

Question

I'm using spring jpa with Mysql.

I am trying to implement the folowing solution for bypassing the generated id field: Bypass GeneratedValue in Hibernate (merge data not in db?)

The problem is that when the id is null and should be generated I get : "field 'id' doesn't have a default value"

My entity:

    @Entity
public class RegistrationDetails{

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY, generator = "IdOrGenerated")
    @GenericGenerator(name = "IdOrGenerated", strategy = "com.xxx.common.UseIdOrGenerate")
    @Column(name = "ID", nullable = false)
    private Long id;

    @Column(nullable = false)
    private String firstName;
}

my generator:

    public class UseIdOrGenerate extends IdentityGenerator {

        @Override
        public Serializable generate(SessionImplementor session, Object obj) throws HibernateException {

        if (obj == null)
            throw new HibernateException(
                         new NullPointerException());

        if ((((RegistrationDetails) obj).getId()) == null) {
            Serializable id = super.generate(
                             session,
                             obj);
            return id;
        }
        else {
     return ((RegistrationDetails) obj).getId();

        }
        }

}

From some conversations I think it something about the Auto increment filed but I cant add it in MySql.

EDIT: My tables are generated automatically when the tomcat server starts. the problem is that it doesn't set the id field as auto increment. Is there a hibernate annotation for this?

The table is generated when the tomcat server starts, is there a jpa annotation? GenerationType.auto doesnt work — lior, Apr 16 '14 at 08:57
when i try Manually in the mysql workbanch and it gives an error — lior, Apr 16 '14 at 08:58
the error: Cannot change column 'ID': used in a foreign key constraint. and I'm using jpa repository for save — lior, Apr 16 '14 at 09:39
How did you generated the table? is the id column set as "auto generate"? — lior, Apr 16 '14 at 09:51

score 0 · Answer 1 · edited May 23 '17 at 11:49

0

Refer the link Hibernate Auto Increment ID

You can use GenerationType.AUTO to create . For details refer link above

edited May 23 '17 at 11:49

Community

1
1

answered Apr 16 '14 at 10:04

muthukumar

2,233
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maybe I cant get it to work because I;m using hibernate as a JPA provider and not pure hibernate? – lior Apr 16 '14 at 11:39

Generated value exception java jpa

1 Answers1