I was following Hibernate: Use a Base Class to Map Common Fields and openjpa inheritance tutorial to put common columns like ID, lastModifiedDate etc in base table.

My annotated mappings are as follow :

BaseTable :

@MappedSuperclass
public abstract class BaseTable {
    @Id
    @GeneratedValue
    @Column(name = "id")
    private int id;

    @Column(name = "lastmodifieddate")
    private Date lastModifiedDate;
...

Person table -

@Entity
@Table(name = "Person ")
public class Person extends BaseTable  implements Serializable{
...

Create statement generated :

create table Person (id integer not null auto_increment,  lastmodifieddate datetime, name varchar(255), primary key (id)) ; 

After I save a Person object to db,

Person p = new Person();
p.setName("Test");
p.setLastModifiedDate(new Date());
..

getSession().save(p);

I am setting the date field but, it is saving the record with generated ID and LastModifiedDate = null, and Name="Test".

Insert Statement :

insert into Person (lastmodifieddate, name) values (?, ?)
binding parameter [1] as [TIMESTAMP] - <null>
binding parameter [2] as [VARCHAR] - Test

Read by ID query : When I do hibernate query (get By ID) as below, It reads person by given ID.

Criteria c = getSession().createCriteria(Person.class);
c.add(Restrictions.eq("id", id));
Person person= c.list().get(0);
//person has generated ID, LastModifiedDate is null

select query select person0_.id as id8_,  person0_.lastmodifieddate as lastmodi8_, person0_.name as person8_ from Person person0_
 - Found [1] as column [id8_]
 - Found [null] as column [lastmodi8_]
 - Found [Test] as column [person8_]

ReadAll query : //read all Query query = getSession().createQuery("from " + Person.class.getName()); List allPersons=query.list();

Corresponding SQL for read all

select query select person0_.id as id8_,  person0_.lastmodifieddate as lastmodi8_, person0_.name as person8_ from Person person0_
- Found [1] as column [id8_]
- Found [null] as column [lastmodi8_]
- Found [Test] as column [person8_]
- Found [2] as column [id8_]
- Found [null] as column [lastmodi8_]
- Found [Test2] as column [person8_]

But when I print out the list in console, its being more weird. it is selecting List of Person object with

• ID fields = all 0 (why all 0 ?)
• LastModifiedDate = null
• Name fields have valid values

I don't know whats wrong here. Could you please look at it?

FYI,

My Hibernate-core version : 4.1.2, MySQL Connector version : 5.1.9 .

In summary, There are two issues here

• Why I am getting All ID Fields =0 when using read all?
• Why the LastModifiedDate is not being inserted?