JPQL：EclipseLink 和 Hibernate 的区别

Question

I already asked about my situation and didn't find a proper solution. After some additional search I think I know the source problem although don't know how to resolve it. As mentioned I have:

@Table(name = "role__parent")
@IdClass(RoleAssociationKey.class)
@Data
public class RoleAssociation implements Serializable {

    @Id
    @JoinColumn(name = "has_parent_role_id")
    private Role node;

    @Id
    @JoinColumn(name = "is_parent_for_role_id")
    private Role parent;
    ...
}
@Data
class RoleAssociationKey implements Serializable {
    private static final long serialVersionUID = 1L;
    private int node;
    private int parent;
}

and I have

@Table(name = "role")
@Data
public class Role implements IRole {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @OneToMany(mappedBy = "node", orphanRemoval = true, cascade = { CascadeType.ALL })
    private List<RoleAssociation> parentRoles;
    ...

Up to this point I think nothing special. I have the query:

@NamedQuery(name = "Role.findParents", query = 
   "SELECT r FROM Role r JOIN RoleAssociation ra ON r.id = ra.parent.id WHERE ra.node.id = :id")

with the purpose to all set parents. When I compile it Hibernate complains left and right hand sides of a binary logic operator were incompatible [integer : component[node,parent]]

Since the statement works in EclipseLink I have no clue how to change it into a working Hibernate one. Help would be highly appreciated.

Answer 1

After some struggels I finally figured the root cause of this problem. I'm aware that the SQL might be improved nevertheless I fail at other similar spots.

Hibernate requires to have a matching pair for @OneToMany relation.

In my query I refer to the parent of my role. The solution is

@Data
public class RoleAssociation implements Serializable {

    @Id
    @JoinColumn(name = "has_parent_role_id")
    @ManyToOne // <<<<==== rerequired for Hibernate
    private Role node;

    @Id
    @JoinColumn(name = "is_parent_for_role_id")
    @ManyToOne // <<<<==== rerequired for Hibernate
    private Role parent;

I have no clue why Hibernate complains while EclipseLink can fetch the required information. Nevertheless with this additional annoation the code works!