Handle DateTime in JPA2

Question

I'm using JPA2 with EclipseLink implementation. I'm simply trying to save the current Date into a DateTime column into a MySQL Database.

The date object which should be persisted is simply created:

import java.util.Date
Date currentDate = new Date();

Now the currentDate contains the exact date and time. This object is persisted in a table which has the following column:

@Column(name="DATE_CREATED")
@Temporal(TemporalType.DATE)
Date dateCreated;

The TemporalType has three constants:

• DATE - this saves in the DB the date without any time: (2012-02-23 00:00:00)
• TIME - this throws an incompatibility error
• TIMESTAMP - this saves in the DB the date without any time: (2012-02-23 00:00:00)

The database column is created this way:

date_opening DATETIME NULL DEFAULT NULL,

For all this options I'm failing in saving the both the time and the date.

Answer 1

This should work perfectly with TemporalType.TIMESTAMP and database column type DATETIME. Maybe you are checking type for wrong column: in mappings you have "DATE_CREATED" and in column definition "date_opening".

You asked also why there is no TemporalType.DATETIME. Reason is that values of TemporalType have one-to-one mapping to JDBC temporal types in java.sql.[DATE/TIME/TIMESTAMP], in the end JPA have to play together with JDBC.

I tested with following code (env: EclipseLink 2.3.0, Connector/J 5.1.6, MySQL 5.1):

Entity/mappings:

@Entity
public class SomeEntity {
    @Id
    private int id;

    @Column(name="DATE_CREATED")
    @Temporal(TemporalType.TIMESTAMP)
    private java.util.Date dateCreated;

    public SomeEntity(int id, Date dateCreated) {
        this.id = id;
        this.dateCreated = dateCreated;
    }
    public SomeEntity() {
    }
}

Table definition:

CREATE TABLE  `test`.`SOMEENTITY` (
  `ID` int(11) NOT NULL,
  `DATE_CREATED` datetime DEFAULT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=innoDB DEFAULT CHARSET=utf8

Test:

java.util.Date now = new Date();
SomeEntity se = new SomeEntity(1, now);
em.persist(se);

It works as expected, also time part of DATE_CREATED is having correct value. If mismatch between columns was not the problem, maybe you can test this as well, and report results and MySQL and library versions.

Answer 2

With the mapping :

@Temporal(TemporalType.TIMESTAMP)
    private java.util.Date dateCreated;

when you retrieve the data from MySQL - it gives something like :

1519621200000