如何使用构造函数在选择子句中为多个表的选定列编写HQL JOIN查询

我正在使用Constructor()在Select子句中为多个表的选定列编写HQL JOIN查询

我有以下实体：

实体1：NotificationObject.java

@Entity
@Table(name="notification_object")
public class NotificationObject implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue( strategy=GenerationType.IDENTITY )
    @Column( columnDefinition="INT(10) UNSIGNED" )
    private Integer id;

    @Column( name="entity_type_id",columnDefinition="TINYINT UNSIGNED",nullable=false )
    private Short entityTypeId;

    @Column( name="entity_id",columnDefinition="INT(10) UNSIGNED",nullable=false )
    private Integer entityId;

    @DateTimeFormat( pattern="yyyy-MM-dd" )
    @Temporal( TemporalType.TIMESTAMP )
    @CreationTimestamp
    @Column( name="created_on"/*,nullable=false*/ )
    private Date createdOn;

    @OneToMany( mappedBy = "notificationObject" )
    private Set<Notification> notifications = new LinkedHashSet<>();

    public NotificationObject() {}
    public NotificationObject(Short entityTypeId,Integer entityId) {
        this.entityTypeId = entityTypeId;
        this.entityId = entityId;
    }

    // Getters and Setters
}

实体2：NotificationChange.java

@Entity
@Table(name="notification_change")
public class NotificationChange implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(columnDefinition="INT(10) UNSIGNED")
    private Integer id;

    @ManyToOne( fetch=FetchType.LAZY )
    @JoinColumn(
            name="notification_object_id",nullable=false,foreignKey=@ForeignKey(name="fk_notification_change_notification_object_noti_object_id")
    )
    private NotificationObject notificationObject;

    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn( 
            name="actor_id",foreignKey=@ForeignKey(name="fk_notification_change_user_user_id")
    )
    private User actor;

    public NotificationChange() {}
    public NotificationChange( User actor ) {
        this.actor = actor;
    }

    // Getters and Setters
}

实体3：Notification.java

@Entity
@Table(name="notification")
public class Notification implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue( strategy=GenerationType.IDENTITY )
    @Column( columnDefinition="INT(10) UNSIGNED" )
    private Integer id;

    @ManyToOne( fetch=FetchType.LAZY )
    @JoinColumn(
            name="notification_object_id",foreignKey=@ForeignKey(name="fk_notification_notification_object_notification_object_id")
    )
    private NotificationObject notificationObject;

    @ManyToOne( fetch=FetchType.LAZY )
    @JoinColumn(
            name="notifier_id",foreignKey=@ForeignKey(name="fk_notification_user_user_id")
    )
    private User notifier;

    @Column( name="is_seen",nullable=false )
    private boolean isSeen;

    @Column( name="is_viewed",nullable=false )
    private boolean isViewed;

    public Notification() {}
    public Notification( User notifier,boolean isSeen,boolean isViewed ) {
        this.notifier = notifier;
        this.isSeen = isSeen;
        this.isViewed = isViewed;
    }

    // Getters and Setters
}

实体4：User.java

@Entity
@Table(name="user")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="user_id")
    private String user_id;

    // Extra fields

    @OneToOne(cascade=CascadeType.MERGE)
    @JoinColumn(name="emp_id",columnDefinition="INT(10) UNSIGNED")
    private Employee employee;

    @OneToMany( mappedBy="notifier" )
    private Set<Notification> notifications = new LinkedHashSet<>();

    public User() {}
    public User(String user_id) {
        this.user_id = user_id;
    }

    // Getters and Setters
}

实体5：Employee.java

@Entity
@Table(name="employee")
public class Employee implements Serializable {

    private static final long serialVersionUID = 1L;

    public Employee() { }
    public Employee( String emp_id ) {
        this.emp_id = emp_id;
    }

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="emp_id")
    private String emp_id;

    @Column(name="first_name")
    private String first_name;

    @Column(name="last_name")
    private String last_name;

    // Extra fields

    @OneToOne(mappedBy="employee")
    @JsonBackReference
    private User user;

    // Getters and Setters
}

DTO 1：Notify.java

public class Notify {
    private Integer notificationObjectId,notificationId,notifierId,actorId,entityId;
    private Short entityTypeId;
    private String notifierName,actorName,message,notificationLink;
    private Date createdOn;
    private boolean isSeen,isViewed;

    public Notify() {}
    public Notify ( Integer notificationObjectId,Integer notificationId,Integer notifierId,Integer actorId,Integer entityId,Short entityTypeId,String notifierName,String actorName,String message,String notificationLink,Date createdOn,boolean isViewed ) {
        // Set Values Here
    }
    public Notify (Integer notificationObjectId,boolean isViewed ) {
        // Or Here
    }

    // Getters and Setters          
}

我在JOINs很弱.
我想为实体的选定字段编写HQL JOIN查询以形成Constructor()在Notify.java DTO的Select子句中.
我试过的：

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