Does JPA support mapping to sql views?

While using the @Id annotation with fields of directly supported types is not the only way to specify an entity's identity (see @IdClass with multiple @Id annotations or @EmbeddedId with @Embedded), the JPA specification requires a primary key for each entity.

That said, you don't need entities to use JPA with database views. As mapping to a view is no different from mapping to a table from an SQL perspective, you could still use native queries (createNativeQuery on EntityManager) to retrieve scalar values instead.