如何編寫休眠OneToMany關系的hql查詢？

Question

我的班級安排如下：

class User {
    @Id
    private long id;

    @OneToMany(fetch = FetchType.EAGER,cascade = CascadeType.ALL)
    Set<UserRole> userRoles;
}

class UserRole {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", unique = true, nullable = false)
    private int id;

    @Column(name = "role", nullable = false, length = 45)
    private String role;
   }

我正在嘗試使用以下查詢來查詢具有特定角色的用戶（在這種情況下，所有具有ROLE_ADMIN角色的用戶）：

    org.hibernate.query.Query<User> userQuery=session.createQuery("from User as mc where mc.userRoles in (from UserRole as ur where ur.role in (:uRoles))",User.class);
    Set<String> roles = new HashSet<String>();
    roles.add("ROLE_ADMIN");
    userQuery.setParameterList("uRoles", roles);
    List<User> admins = userQuery.getResultList();

但是，查詢不返回任何結果。

Answer 1

session.createQuery(
  "from User as user join user.userRoles as userRole where userRole.role in :roles")
  .setParameter("roles", Arrays.asList("ROLE_ADMIN"))
  .getResultList();