Setting a JPA timestamp column to be generated by the database?

Question

In my SQL Server 2000 database, I have a timestamp (in function not in data type) column of type DATETIME named lastTouched set to getdate()<

Answer 1

I do not think that every database has auto-update timestamps (e.g. Postgres). So I've decided to update this field manually everywhere in my code. This will work with every database:

thingy.setLastTouched(new Date());
HibernateUtil.save(thingy);

There are reasons to use triggers, but for most projects, this is not one of them. Triggers dig you even deeper into a specific database implementation.

MySQL 5.6.28 (Ubuntu 15.10, OpenJDK 64-Bit 1.8.0_66) seems to be very forgiving, not requiring anything beyond

@Column(name="LastTouched")

MySQL 5.7.9 (CentOS 6, OpenJDK 64-Bit 1.8.0_72) only works with

@Column(name="LastTouched", insertable=false, updatable=false)

not:

FAILED: removing @Temporal
FAILED: @Column(name="LastTouched", nullable=true)
FAILED: @Column(name="LastTouched", columnDefinition="TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP")

My other system info (identical in both environments)

• hibernate-entitymanager 5.0.2
• hibernate-validator 5.2.2
• mysql-connector-java 5.1.38