Enumerates flush modes recognized by the EntityManager.

When queries are executed within a transaction, if AUTO is set on the Query or TypedQuery object, or if the flush mode setting for the persistence context is AUTO (the default) and a flush mode setting has not been specified for the Query or TypedQuery object, the persistence provider is responsible for ensuring that all updates to the state of all entities in the persistence context which could potentially affect the result of the query are visible to the processing of the query. The persistence provider implementation may achieve this by flushing updates to those entities to the database or by some other means.

On the other hand, if COMMIT is set, the effect of updates made to entities in the persistence context on queries is unspecified.

If there is no transaction active or the persistence context is not joined to the current transaction, the persistence provider must not flush to the database.