org.eclipse.persistence.annotations

Annotation Type VariableOneToOne

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

Variable one to one mappings are used to represent a pointer references between a java object and an implementer of an interface. This mapping is usually represented by a single pointer (stored in an instance variable) between the source and target objects. In the relational database tables, these mappings are normally implemented using a foreign key and a type code. A VariableOneToOne can be specified within an Entity, MappedSuperclass and Embeddable class.

Author:

Guy Pelletier

Since:

Eclipselink 1.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
CascadeType[]	cascade (Optional) The operations that must be cascaded to the target of the association.
DiscriminatorClass[]	discriminatorClasses (Optional) The list of discriminator types that can be used with this VariableOneToOne.
DiscriminatorColumn	discriminatorColumn (Optional) The discriminator column will hold the type indicators.
FetchType	fetch (Optional) Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched.
boolean	optional (Optional) Whether the association is optional.
boolean	orphanRemoval (Optional) Whether to apply the remove operation to entities that have been removed from the relationship and to cascade the remove operation to those entities.
java.lang.Class	targetInterface (Optional) The interface class that is the target of the association.

Element Detail

targetInterface

public abstract java.lang.Class targetInterface

(Optional) The interface class that is the target of the association. If not specified it will be inferred from the type of the object being referenced.

Default:

void.class

cascade

public abstract CascadeType[] cascade

(Optional) The operations that must be cascaded to the target of the association.

Default:

{}

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) Whether the association is optional. If set to false then a non-null relationship must always exist.

Default:

true

orphanRemoval

public abstract boolean orphanRemoval

(Optional) Whether to apply the remove operation to entities that have been removed from the relationship and to cascade the remove operation to those entities.

Default:

false

discriminatorColumn

public abstract DiscriminatorColumn discriminatorColumn

(Optional) The discriminator column will hold the type indicators. If the DiscriminatorColumn is not specified, the name of the discriminator column defaults to "DTYPE" and the discriminator type to STRING.

Default:

@javax.persistence.DiscriminatorColumn

discriminatorClasses

public abstract DiscriminatorClass[] discriminatorClasses

(Optional) The list of discriminator types that can be used with this VariableOneToOne. If none are specified then those entities within the persistence unit that implement the target interface will be added to the list of types. The discriminator type will default as follows: - If DiscriminatorColumn type is STRING: Entity.name() - If DiscriminatorColumn type is CHAR: First letter of the Entity class - If DiscriminatorColumn type is INTEGER: The next integer after the highest integer explicitly added.

Default:

{}