10.2. Dedicated version number

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The version number mechanism for optimistic locking is provided through a `@Version` annotation.

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<div class="title">Example 276. @Version annotation</div>
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<pre class="prettyprint highlight">`@Version
private long version;`</pre>
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Here, the version property is mapped to the `version` column, and the entity manager uses it to detect conflicting updates,
and prevent the loss of updates that would otherwise be overwritten by a last-commit-wins strategy.

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The version column can be any kind of type, as long as you define and implement the appropriate `UserVersionType`.

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Your application is forbidden from altering the version number set by Hibernate.
To artificially increase the version number, see the documentation for properties `LockModeType.OPTIMISTIC_FORCE_INCREMENT` or
`LockModeType.PESSIMISTIC_FORCE_INCREMENT` check in the Hibernate Entity Manager reference documentation.

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If the version number is generated by the database, such as a trigger, use the annotation `@org.hibernate.annotations.Generated(GenerationTime.ALWAYS)` on the version attribute.

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