Annotation Type Any

  • @Target({METHOD,FIELD})
    public @interface Any
    Maps a to-one cardinality association taking values over several entity types which are not related by the usual entity inheritance, using a discriminator value stored on the referring side of the relationship.

    This is quite different to discriminated inheritance where the discriminator is stored along with the referenced entity hierarchy.

    For example, consider an Order entity containing Payment information, where a Payment might be a CashPayment or a CreditCardPayment. An @Any mapping would store the discriminator value identifying the concrete type of Payment along with the state of the associated Order, instead of storing it with the Payment entity itself.

    In this example, Payment would not be declared as an entity type, and would not be annotated @Entity. It might even be an interface, or at most just a mapped superclass, of CashPayment and CreditCardPayment. So in terms of the object/relational mappings, CashPayment and CreditCardPayment would not be considered to participate in the same entity inheritance hierarchy.

    It's reasonable to think of the "foreign key" in an Any mapping is really a composite value made up of the foreign key and discriminator taken together. Note, however, that this composite foreign key is only conceptual and cannot be declared as a physical constraint on the relational database table.

    Of course, Any mappings are disfavored, except in extremely special cases, since it's much more difficult to enforce referential integrity at the database level.
    See Also:
    • Optional Element Summary

      Optional Elements 
      Modifier and Type Optional Element Description
      jakarta.persistence.FetchType fetch
      Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched.
      boolean optional
      Whether the association is optional.
    • Element Detail

      • fetch

        jakarta.persistence.FetchType fetch
        Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched. The EAGER strategy is a requirement on the persistence provider runtime that the value must be eagerly fetched. The LAZY strategy is applied when bytecode enhancement is used. If not specified, defaults to EAGER.
      • optional

        boolean optional
        Whether the association is optional. If set to false then a non-null relationship must always exist.