javax.persistence.AssociationOverride Maven / Gradle / Ivy
package javax.persistence;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* Used to override a mapping for an entity relationship.
*
*
* May be applied to an entity that extends a mapped superclass to override a relationship mapping defined by the mapped superclass. If not
* specified, the association is mapped the same as in the original mapping. When used to override a mapping defined by a mapped superclass,
* AssociationOverride is applied to the entity class.
*
*
* May be used to override a relationship mapping from an embeddable within an entity to another entity when the embeddable is on the owning
* side of the relationship. When used to override a relationship mapping defined by an embeddable class (including an embeddable class
* embedded within another embeddable class), AssociationOverride is applied to the field or property containing the
* embeddable.
*
*
* When AssociationOverride is used to override a relationship mapping from an embeddable class, the name element
* specifies the referencing relationship field or property within the embeddable class. To override mappings at multiple levels of
* embedding, a dot (".") notation syntax must be used in the name element to indicate an attribute within an embedded
* attribute. The value of each identifier used with the dot notation is the name of the respective embedded field or property.
*
*
* When AssociationOverride is applied to override the mappings of an embeddable class used as a map value, "
* value." must be used to prefix the name of the attribute within the embeddable class that is being overridden in order to
* specify it as part of the map value.
*
*
* If the relationship mapping is a foreign key mapping, the joinColumns element is used. If the relationship mapping uses a
* join table, the joinTable element must be specified to override the mapping of the join table and/or its join columns.
*
*
*
*
* Example 1: Overriding the mapping of a relationship defined by a mapped superclass
*
* @MappedSuperclass
* public class Employee {
* ...
* @ManyToOne
* protected Address address;
* ...
* }
*
* @Entity
* @AssociationOverride(name="address",
* joinColumns=@JoinColumn(name="ADDR_ID"))
* // address field mapping overridden to ADDR_ID foreign key
* public class PartTimeEmployee extends Employee {
* ...
* }
*
*
*
* Example 2: Overriding the mapping for phoneNumbers defined in the ContactInfo class
*
* @Entity
* public class Employee {
* @Id int id;
* @AssociationOverride(
* name="phoneNumbers",
* joinTable=@JoinTable(
* name="EMPPHONES",
* joinColumns=@JoinColumn(name="EMP"),
* inverseJoinColumns=@JoinColumn(name="PHONE")
* )
* )
* @Embedded ContactInfo contactInfo;
* ...
* }
*
* @Embeddable
* public class ContactInfo {
* @ManyToOne Address address; // Unidirectional
* @ManyToMany(targetEntity=PhoneNumber.class) List phoneNumbers;
* }
*
* @Entity
* public class PhoneNumber {
* @Id int number;
* @ManyToMany(mappedBy="contactInfo.phoneNumbers")
* Collection<Employee> employees;
* }
*
*
* @see Embedded
* @see Embeddable
* @see MappedSuperclass
* @see AttributeOverride
*
* @since Java Persistence 1.0
*/
@Target({ TYPE, METHOD, FIELD })
@Retention(RUNTIME)
public @interface AssociationOverride {
/**
* The join column(s) being mapped to the persistent attribute(s). The joinColumns elements must be specified if a foreign
* key mapping is used in the overriding of the mapping of the relationship. The joinColumns element must not be specified
* if a join table is used in the overriding of the mapping of the relationship.
*/
JoinColumn[] joinColumns() default {};
/**
* The join table that maps the relationship. The joinTable element must be specified if a join table is used in the
* overriding of the mapping of the relationship. The joinTable element must not be specified if a foreign key mapping is
* used in the overriding of the relationship.
*
* @since Java Persistence 2.0
*/
JoinTable joinTable() default @JoinTable;
/**
* (Required) The name of the relationship property whose mapping is being overridden if property-based access is being used, or the
* name of the relationship field if field-based access is used.
*/
String name();
}