如何为hibernate OneToMany关系编写hql查询？

Question

我已经制定了，像这样的类：

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; 
    } 

我试图查询具有特定角色的用户（在这种情况下，与角色ROLE_ADMIN所有用户），使用下面的查询：

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，查询没有返回任何结果。

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();