JPA: Map a Map<Enum, Entity> - jpa

Question

i want to Map a map in JPA, but I get a Exception:
My java-code looks like that:
Issue.java:
#ElementCollection
#CollectionTable(
name="ISSUE_EMPLOYEE",
joinColumns=#JoinColumn(name="ISSUE_ID", referencedColumnName="ID")
)
#MapKeyColumn(name="EMPLOYEEPOSITION_ID")
#MapKeyConvert("myEnumConverter")
#JoinColumn(name="EMPLOYEE_ID")
private Map<EmployeePosition, Employee> namedEmployees = new Hashtable<EmployeePosition, Employee>();
EmployeePosition is a Enum andEmployee is a Entity.
I get this Exception :
Internal Exception: java.sql.SQLException: ORA-00904: "EMPLOYEES": invalid identifier
Error Code: 904
Call: INSERT INTO ISSUE_EMPLOYEE (ISSUE_ID, EMPLOYEES, EMPLOYEEPOSITION_ID) VALUES (?, ?, ?)
bind => [27, [B#18b85d, SERVICE]
It seems to ignore the #JoinColumn annotation and tries to insert the object in the DB.
What´s wrong with my mapping/Is it possible to match Entities like this?

Answer 1

As far as I understand, you need #OneToMany instead of #ElementCollection when value of a Map is an entity. Something like this:
#OneToMany
#JoinTable(name = "ISSUE_EMPLOYEE",
joinColumn = #JoinColumn(name = "ISSUE_ID"),
inverseJoinColumn = #JoinColumn("EMPLOYEE_ID"))
#MapKeyColumn(name="EMPLOYEEPOSITION_ID")
private Map<EmployeePosition, Employee> namedEmployees = new Hashtable<EmployeePosition, Employee>();
EDIT: The mapping above works fine in Hibernate, but doesn't work in EclipseLink. EMPLOYEEPOSITION_ID column in ISSUE_EMPLOYEE is created, but not used in queries. It happens not only with enum keys, but also with other primitive types.
It looks like a bug in EclipseLink. I can't find in in their Bugzilla, so perhaps it would be better to report it.