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).
(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.
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.