@Target(value={TYPE,METHOD,FIELD})
@Retention(value=RUNTIME)
public @interface AssociationOverride
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; }
Embedded
,
Embeddable
,
MappedSuperclass
,
AttributeOverride
Modifier and Type | Required Element and Description |
---|---|
java.lang.String |
name
(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.
|
Modifier and Type | Optional Element and Description |
---|---|
ForeignKey |
foreignKey
(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.
|
JoinColumn[] |
joinColumns
The join column(s) being mapped to the persistent attribute(s).
|
JoinTable |
joinTable
The join table that maps the relationship.
|
public abstract java.lang.String name
public abstract JoinColumn[] joinColumns
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.public abstract JoinTable joinTable
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.public abstract ForeignKey foreignKey