org.eclipse.persistence.annotations

Annotation Type Transformation

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

Transformation is an optional annotation for org.eclipse.persistence.mappings.TransformationMapping. TransformationMapping allows to map an attribute to one or more database columns. Transformation annotation is an optional part of TransformationMapping definition. Unless the TransformationMapping is write-only, it should have a ReadTransformer, it defines transformation of database column(s) value(s)into attribute value. Also unless it's a read-only mapping, either WriteTransformer annotation or WriteTransformers annotation should be specified. Each WriteTransformer defines transformation of the attribute value to a single database column value (column is specified in the WriteTransformer).

See Also:

ReadTransformer, WriteTransformer, Transformation can be specified within an Entity, MappedSuperclass and Embeddable class.

Author:

Andrei Ilitchev

Since:

EclipseLink 1.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
FetchType	fetch (Optional) Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched.
boolean	optional (Optional) The optional element is a hint as to whether the value of the field or property may be null.

Element Detail

fetch

public abstract FetchType fetch

(Optional) Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched. The EAGER strategy is a requirement on the persistence provider runtime that the value must be eagerly fetched. The LAZY strategy is a hint to the persistence provider runtime. If not specified, defaults to EAGER.

Default:

javax.persistence.FetchType.EAGER

optional

public abstract boolean optional

(Optional) The optional element is a hint as to whether the value of the field or property may be null. It is disregarded for primitive types, which are considered non-optional.

Default:

true