Package jakarta.persistence
Annotation Interface CollectionTable
Specifies the table that is used for the mapping of collections of
basic or embeddable types. Applied to the collection-valued field
or property.
By default, the columns of the collection table that correspond
to the embeddable class or basic type are derived from the
attributes of the embeddable class or from the basic type according
to the default values of the Column annotation. In the case
of a basic type, the column name is derived from the name of the
collection-valued field or property. In the case of an embeddable
class, the column names are derived from the field or property
names of the embeddable class.
- To override the default properties of the column used for a
basic type, the
Columnannotation is used on the collection-valued attribute in addition to theElementCollectionannotation. - To override these defaults for an embeddable class, the
AttributeOverrideand/orAttributeOverridesannotations can be used in addition to theElementCollectionannotation. If the embeddable class contains references to other entities, the default values for the columns corresponding to those references may be overridden by means of theAssociationOverrideand/orAssociationOverridesannotations.
If the CollectionTable annotation is missing, the default
values of the CollectionTable annotation elements apply.
Example:
@Embeddable
public class Address {
protected String street;
protected String city;
protected String state;
...
}
@Entity
public class Person {
@Id
protected String ssn;
protected String name;
protected Address home;
...
@ElementCollection // use default table (PERSON_NICKNAMES)
@Column(name = "name", length = 50)
protected Set<String> nickNames = new HashSet<>();
...
}
@Entity
public class WealthyPerson extends Person {
@ElementCollection
@CollectionTable(name = "HOMES") // use default join column name
@AttributeOverrides({
@AttributeOverride(name = "street",
column = @Column(name = "HOME_STREET")),
@AttributeOverride(name = "city",
column = @Column(name = "HOME_CITY")),
@AttributeOverride(name="state",
column = @Column(name = "HOME_STATE"))})
protected Set<Address> vacationHomes = new HashSet<>();
...
}
- Since:
- 2.0
- See Also:
-
Optional Element Summary
Optional ElementsModifier and TypeOptional ElementDescription(Optional) The catalog of the table.(Optional) Used to specify or control the generation of a foreign key constraint for the columns corresponding to thejoinColumns()element when table generation is in effect.Index[](Optional) Indexes for the table.(Optional) The foreign key columns of the collection table which reference the primary table of the entity.(Optional) The name of the collection table.(Optional) A SQL fragment appended to the generated DDL statement which creates this table.(Optional) The schema of the table.(Optional) Unique constraints that are to be placed on the table.
-
Element Details
-
name
String name(Optional) The name of the collection table. If not specified, it defaults to the concatenation of the name of the containing entity and the name of the collection attribute, separated by an underscore.- Default:
""
-
catalog
String catalog(Optional) The catalog of the table. If not specified, the default catalog is used.- Default:
""
-
schema
String schema(Optional) The schema of the table. If not specified, the default schema for the user is used.- Default:
""
-
joinColumns
JoinColumn[] joinColumns(Optional) The foreign key columns of the collection table which reference the primary table of the entity. The default only applies if a single join column is used. The default is the same as forJoinColumn(i.e., the concatenation of the following: the name of the entity; "_"; the name of the referenced primary key column.) However, if there is more than one join column, aJoinColumnannotation must be specified for each join column using theJoinColumnsannotation. In this case, both thenameandreferencedColumnNameelements must be specified by each suchJoinColumnannotation.- Default:
{}
-
foreignKey
ForeignKey foreignKey(Optional) Used to specify or control the generation of a foreign key constraint for the columns corresponding to thejoinColumns()element when table generation is in effect. If both this element and theforeignKeyelement of any of thejoinColumnselements are specified, the behavior is undefined. If no foreign key annotation element is specified in either location, a default foreign key strategy is selected by the persistence provider.- Since:
- 2.1
- Default:
@jakarta.persistence.ForeignKey(PROVIDER_DEFAULT)
-
uniqueConstraints
UniqueConstraint[] uniqueConstraints(Optional) Unique constraints that are to be placed on the table. These are only used if table generation is in effect.- Default:
{}
-
indexes
Index[] indexes(Optional) Indexes for the table. These are only used if table generation is in effect.- Since:
- 2.1
- Default:
{}
-
options
String options(Optional) A SQL fragment appended to the generated DDL statement which creates this table. This is only used if table generation is in effect.- Since:
- 3.2
- Default:
""
-