Hibernate @Generated annotation doesn't work well

Question

I want to use @org.hibernate.annotations.Generated to update 'lastModified' field automatically, Here is my code:

Bill:

@Entity
public class Bill {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    protected Long id;

    @Temporal(TemporalType.TIMESTAMP)
    @Column(insertable = false, updatable = false)
    @org.hibernate.annotations.Generated(GenerationTime.ALWAYS)
    protected Date lastModified;

    @Column
    protected String description;

    public void setDescription(String description) {
        this.description = description;
    }

    public Date getLastModified() {
        return lastModified;
    }

    public void setLastModified(Date lastModified) {
        this.lastModified = lastModified;
    }

    public String getDescription() {
        return description;
    }
}

Main:

public static void main(String[] args) {
        Session session = factory.openSession();
        Transaction tx = session.beginTransaction();
        Bill bill1 = new Bill();
        session.persist(bill1);
        Bill bill2 = new Bill();
        session.persist(bill2);
        bill1.setDescription("Bill1 modified");
        tx.commit();
        factory.close();
    }

When I checked bills by sql manually, it showed:

id | description | lastModified |

--- | -------------- | ---------------- |

1 | Bill1 modified | null
2 | null | null

My hibernate version is 5.2.9.Final, and mysql version is 5.7.16. I tried to remove 'insertable = false, updatable = false' but it didn't work either.

Possible duplicate of [How to annotate MYSQL autoincrement field with JPA annotations](https://stackoverflow.com/questions/4102449/how-to-annotate-mysql-autoincrement-field-with-jpa-annotations) — K.Nicholas, Jun 16 '17 at 15:52

Abass A · Accepted Answer · 2017-06-16T18:44:19.097

You can use @CreationTimestamp and @UpdateTimestamp instead:

@CreationTimestamp
private Date created;
@UpdateTimestamp
private Date lastModified;

Timestamp generated with theses annotations are in-memory generation based on VM time.

If you need timestamp generated by your database you must use a custom annotation, marked with @ValueGenerationType.

See the following link for details : http://docs.jboss.org/hibernate/orm/4.3/topical/html/generated/GeneratedValues.html#_in_database_generation

Hibernate @Generated annotation doesn't work well

1 Answers1