I have a MySQL table:
mysql> show create table items\G
*************************** 1. row ***************************
Table: items
Create Table: CREATE TABLE `items` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(128) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
1 row in set (0.02 sec)
I create new rows from a Java program via an Entity class:
@Entity
@Table(name = "items", schema = "office_db")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Items.findAll", query = "SELECT i FROM Items i"),
@NamedQuery(name = "Items.findById", query = "SELECT i FROM Items i WHERE i.id = :id"),
@NamedQuery(name = "Items.findByName", query = "SELECT i FROM Items i WHERE i.name = :name"),
@NamedQuery(name = "Items.findByCreated", query = "SELECT i FROM Items i WHERE i.created = :created")
})
public class Items implements Serializable {
@Column(name = "name",length = 128)
private String name;
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "id")
private Integer id;
@Basic(optional = false)
@Column(name = "created")
@Temporal(TemporalType.TIMESTAMP)
private Date created;
@OneToMany(mappedBy = "itemId")
private Collection<Documents> documentsCollection;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "items")
private Collection<ItemAttributes> itemAttributesCollection;
(more stuff ...)
I only set the NAME column, and as expected, the ID and CREATED are set by default:
mysql> select * from items;
+----+--------+---------------------+
| id | name | created |
+----+--------+---------------------+
| 2 | Case 2 | 2017-10-31 13:47:52 |
| 3 | Case 3 | 2017-10-31 13:48:02 |
+----+--------+---------------------+
2 rows in set (0.00 sec)
However, when I reload the table into Java later in the same session:
public List<Items>findItems(){
TypedQuery<Items> query=
em.createNamedQuery("Items.findAll",Items.class);
return query.getResultList();
}
the ID column is loaded correctly, but the CREATED column comes up as blank. CREATED shows up correctly if I relaunch the application (this runs on a glassfish server). My guess is that the reason for this difference is the @GeneratedValue annotation on ID, but I can't apply it on the CREATED field, it seems, or at least not naively. What is the correct way to make the generated timestamp load?
