问如何在没有JPA实体类的情况下使用JPQL从映射表检索数据

EN

@Entity
@Table(name="users")
public class User extends  Persistent{

@NotEmpty
@Size(min=4,max=16)
@Column(name="USER_NAME",nullable = false,unique = true)
private String username;

@NotEmpty
@Email
@Column(name="EMAIL",nullable = false,unique = true)
private String email;

@NotEmpty
@Size(min=3,max=99)
@Column(name="PASSWORD",nullable = false)
private String password;


@Column(name="ACTIVE")
private boolean active = true;

@NotEmpty
@Column(name="FIRST_NAME",nullable = false)
private String firstName;

@NotEmpty
@Column(name="LAST_NAME",nullable = false)
private String lastName;

@NotEmpty
@Column(name="DOB",nullable = false)
private String DOB;

@Column(name="PROFILE_PICTURE")
private String profilePicture;

//user activities

@OneToMany(mappedBy = "user",fetch = FetchType.LAZY,cascade = CascadeType.REMOVE)
private List<Post> posts;

@OneToMany(mappedBy = "user",fetch = FetchType.LAZY,cascade = CascadeType.REMOVE)
private List<Comment> comments;

@OneToMany(mappedBy = "user",fetch = FetchType.LAZY,cascade = CascadeType.REMOVE)
private List<Like> likes;

@ManyToMany(cascade={CascadeType.ALL},fetch=FetchType.EAGER)
@JoinTable(name="friends",
        joinColumns={@JoinColumn(name="userId")},
        inverseJoinColumns={@JoinColumn(name="friendId")})
private List<User> friends;

@ManyToMany(mappedBy="friends",fetch=FetchType.EAGER)
private List<User> friendsWith;
..... 
}