Code committed in revision r750517 supports general/qualified identification variables appear in selections:
select KEY(e) from PhoneNumber p, in (p.emps) e
select ENTRY(e) from PhoneNumber p, in (p.emps) e
select VALUE(e) from PhoneNumber p, in (p.emps) e
in which emps is a relation field of java type Map<K,V> .
JPA2 JPQL syntax allows qualified identification variables to appear in single_valued_path_expression, which implies that
KEY(e) and VALUE(e) can be used to as a path and also can be further navigated to its fields or relations. Those support will be added in iteration 5.
More testcases will be added to cover additional annotations using @MapKeyClass and @MapKeyJoinColumns.