@Target(METHOD)
@Retention(RUNTIME)
public @interface AllowUpdatableEntityViews

Specifies that the annotated attribute is allowed to use an updatable entity view type even if it is an owned *ToOne relation. By default, it is disallowed to use an updatable entity view type for owned *ToOne relationships because it is rarely necessary and often results in more problems than it solves. It is vital for a user to understand the implications of allowing updatable entity view types for such relationships. Updatable entity views only allow to model updates of tree-like structures, but not graphs. It is currently a technical limitation because dirty tracking currently only works with a single parent object, but it is also believed that in a domain driven approach, with proper bounded contexts, it is not needed. The technical limitation manifests itself at runtime, when it encounters a graph like updatable object structure. When loading an updatable entity view that contains an owned *ToOne relationship, it is possible for two different root objects to refer to the same sub-object via the *ToOne relationship. If the entity view type used for the *ToOne relationship is updatable, it could end up having multiple parent objects, which currently isn't allowed and results in an exception. There may be reasons to why the entity model was done this way, but at runtime, the objects conform to a tree-like structure. There are a few cases that are safe. If the relationship is reached from the query root via OneToOne relationships, or the owners of the ManyToOne relationships are guaranteed to have distinct objects, allowing updatable entity view types is safe. At some point, the underlying technical limitation will be removed, yet it will probably not be allowed by default to use updatable entity view types for owned *ToOne relationships.

Since:: 1.3.0
Author:: Christian Beikov

Annotation Type AllowUpdatableEntityViews