javax.persistence

## Annotation Type Version

    @Target(value={METHOD,FIELD})
     @Retention(value=RUNTIME)
    public @interface Version

Specifies the version field or property of an entity class that serves as its optimistic lock value. The version is used to ensure integrity when performing the merge operation and for optimistic concurrency control.

Only a single `Version` property or field should be used per class; applications that use more than one `Version` property or field will not be portable.

The `Version` property should be mapped to the primary table for the entity class; applications that map the `Version` property to a table other than the primary table will not be portable.

The following types are supported for version properties: `int`, `Integer`, `short`, `Short`, `long`, `Long`, `java.sql.Timestamp`.

        Example:

        @Version
        @Column(name="OPTLOCK")
        protected int getVersionNum() { return versionNum; }

Since:
  Java Persistence 1.0