Package jakarta.persistence

Annotation Interface ElementCollection

@Target({METHOD,FIELD})
@Retention(RUNTIME)
public @interface ElementCollection

Declares a collection of instances of a basic type or embeddable class. Must be specified if the collection is to be mapped by means of a collection table.

The CollectionTable annotation specifies a mapping to a database table.

Example:

@Entity
public class Person {
    @Id
    protected String ssn;
    protected String name;
    ...
    @ElementCollection
    protected Set<String> nickNames = new HashSet<>();
    ...
}

Since:

2.0

See Also:

• CollectionTable

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
FetchType	fetch	(Optional) Whether the collection should be lazily loaded or must be eagerly fetched.
Class<?>	targetClass	(Optional) The basic or embeddable class that is the element type of the collection.

Element Details

targetClass

Class<?> targetClass

(Optional) The basic or embeddable class that is the element type of the collection. This element is optional only if the collection field or property is defined using Java generics, and must be specified otherwise. It defaults to the parameterized type of the collection when defined using generics.

Default:

void.class

fetch

FetchType fetch

(Optional) Whether the collection should be lazily loaded or must be eagerly fetched.

• The EAGER strategy is a requirement on the persistence provider runtime that the associated entity must be eagerly fetched.
• The LAZY strategy is a hint to the persistence provider runtime.

If not specified, defaults to LAZY.

Default:

LAZY