JPQL：错误编译 - 状态字段“e.e2.e3”无法解析为有效类型答案

【问题标题】：JPQL: error compiling - state field 'e.e2.e3' cannot be resolved to a valid typeJPQL：错误编译 - 状态字段“e.e2.e3”无法解析为有效类型
【发布时间】：2014-05-26 17:18:40
【问题描述】：

我有这个我无法解决的错误。

Exception Description: Problem compiling [SELECT e FROM ResourceGroup e WHERE e.aclUserResourceGroups.userGroup=:userGroup AND e.aclUserResourceGroups.canView=:canView]. 
[36, 69] The state field path 'e.aclUserResourceGroups.userGroup' cannot be resolved to a valid type.
[87, 118] The state field path 'e.aclUserResourceGroups.canView' cannot be resolved to a valid type.

命名查询：

 SELECT e 
 FROM ResourceGroup e 
 WHERE e.aclUserResourceGroups.userGroup=:userGroup 
 AND e.aclUserResourceGroups.canView=:canView

ERD：

实体：

@Entity
@Table(name="resource_group")
public class ResourceGroup  implements Serializable{

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

    @Column(unique=true)
    private String name;

    @OneToMany(mappedBy = "resourceGroup", cascade = CascadeType.ALL, fetch=FetchType.LAZY, orphanRemoval=true)
    @JoinColumn(name = "resourcegroup_id")
    private List<UserGroupResourceGroup> aclUserResourceGroups;
}

加入实体：

@Entity
@Table(name="user_group_resource_group")
public class UserGroupResourceGroup implements Serializable{

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

    @ManyToOne(targetEntity = UserGroup.class, cascade = CascadeType.PERSIST, fetch=FetchType.LAZY)
    @JoinColumn(name="usergroup_id")
    private UserGroup userGroup = new UserGroup();

    @ManyToOne(targetEntity = ResourceGroup.class, cascade = CascadeType.PERSIST, fetch=FetchType.LAZY)
    @JoinColumn(name="resourcegroup_id")
    private ResourceGroup resourceGroup = new ResourceGroup()
}

用户组：

@Entity
@Table(name="user_group")
public class UserGroup implements Serializable{


    @OneToMany(mappedBy="userGroup", fetch=FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "usergroup_id") 
    private List<AccessControlList> acl;

    @OneToMany(mappedBy="userGroup", fetch=FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "usergroup_id") 
    private List<UserGroupResourceGroup> aclUserResourceGroups;
}

道：

@Override
public List<ResourceGroup> getAllowedResourceGroups(UserGroup userGrp){

     return this.em.createNamedQuery("ResourceGroup.getAllCanView")
                .setParameter("userGroup", userGrp)
                .setParameter("canView", true)
                .getResultList();

}

【问题讨论】：

标签： java jpql jpa-2.1

【解决方案1】：

e.aclUserResourceGroups 是一个集合，您无法通过这种方式访问它。

未测试，但尝试如下：

SELECT e 
FROM ResourceGroup e 
inner join e.aclUserResourceGroups acl
WHERE acl.userGroup=:userGroup 
AND acl.canView=:canView

希望这会有所帮助！

【讨论】：