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== Alternative approaches

An alternative way to maintain a timestamp is to use JDO's `@Version` annotation.
With this approach, it is the JDO/DataNucleus that maintains the version, rather than the framework's `TimestampService`.

For example:

[source,java]
----
@javax.jdo.annotations.Version(
        strategy=VersionStrategy.DATE_TIME,
        column="version")
public class Customer {
    ...
    public java.sql.Timestamp getVersionSequence() {
        return (java.sql.Timestamp) JDOHelper.getVersion(this);
    }
}
----

== See also

* xref:refguide:applib:index/services/clock/ClockService.adoc[ClockService]
+
used to obtain the current time.

* xref:refguide:applib:index/mixins/updates/OnUpdatedBy.adoc[OnUpdatedBy]

* xref:refguide:applib:index/mixins/updates/OnUpdatedByAndAt.adoc[OnUpdatedByAndAt]

