users@glassfish.java.net

Re: Surprising JPA (Toplink) Behaviour (glassfish v1 UR1)

From: <glassfish_at_javadesktop.org>
Date: Sun, 18 Mar 2007 15:24:49 PST

The annotation for row versioning for the dirty read/write problem is... @Version

javax.persistence
Annotation Type Version

--------------------------------------------------------------------------------

@Target(value={METHOD,FIELD})
@Retention(value=RUNTIME)
public @interface VersionThis annotation 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, Timestamp.

    Example:

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

Since:
Java Persistence 1.0
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