/*
* Copyright (c) 2008, 2009, 2011 Oracle, Inc. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution. The Eclipse Public License is available
* at http://www.eclipse.org/legal/epl-v10.html and the Eclipse Distribution License
* is available at http://www.eclipse.org/org/documents/edl-v10.php.
*/
package javax.persistence;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
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 Also: Since: Java Persistence 1.0
/**
* Used to override a mapping for an entity relationship.
* <p>
* <p> 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, <code>AssociationOverride</code> is applied to
* the entity class.
* <p>
* <p> 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),
* <code>AssociationOverride</code> is applied to the field or
* property containing the embeddable.
* <p>
* <p> When <code>AssociationOverride</code> is used to override a
* relationship mapping from an embeddable class, the
* <code>name</code> 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 <code>name</code> 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.
* <p>
* <p> When <code>AssociationOverride</code> is applied to override
* the mappings of an embeddable class used as a map value,
* "<code>value.</code>" 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.
* <p>
* <p> If the relationship mapping is a foreign key mapping, the
* <code>joinColumns</code> element is used. If the relationship
* mapping uses a join table, the <code>joinTable</code> element must
* be specified to override the mapping of the join table and/or its
* join columns.
* <p>
* <p>
* <pre>
* 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 {
* ...
* }
* </pre>
* <p>
* <pre>
* 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;
* }
* </pre>
*
* @see Embedded
* @see Embeddable
* @see MappedSuperclass
* @see AttributeOverride
* @since Java Persistence 1.0
*/
@Target({TYPE, METHOD, FIELD})
@Retention(RUNTIME)
public @interface AssociationOverride {
(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.
/**
* (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();
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.
/**
* The join column(s) being mapped to the persistent attribute(s).
* The <code>joinColumns</code> elements must be specified if a
* foreign key mapping is used in the overriding of the mapping of
* the relationship. The <code>joinColumns</code> 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
/**
* The join table that maps the relationship.
* The <code>joinTable</code> element must be specified if a join table
* is used in the overriding of the mapping of the
* relationship. The <code>joinTable</code> 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;
(Optional) Used to specify or control the generation of a foreign key constraint for the columns
corresponding to the joinColumns element when table generation is in effect.
Since: Java Persistence 2.1
/**
* (Optional) Used to specify or control the generation of a foreign key constraint for the columns
* corresponding to the joinColumns element when table generation is in effect.
*
* @since Java Persistence 2.1
*/
ForeignKey foreignKey() default @ForeignKey(ConstraintMode.PROVIDER_DEFAULT);
}