@manytoone在具有复合键的自引用实体中-@idclass,java,hibernate

Question

花了3天时间寻找解决方案，最后我来到这里寻求社区智慧。

我有如下的自我引用实体：

@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@Entity
@IdClass(CompositeUserId.class)
@Table(name = "user", schema = "dbo")
public class User implements Serializable {
    @Id
    @Column(name = "id")
    private Integer id;

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

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

    @ManyToOne
    @JoinColumn(name = "parent_id", referencedColumnName = "id", insertable = false, updatable = false)
    @JoinColumn(name = "first_name", referencedColumnName = "first_name", insertable = false, updatable = false)
    @JoinColumn(name = "last_name", referencedColumnName = "last_name", insertable = false, updatable = false)
    private User parent;

    @OneToMany(mappedBy = "parent", fetch = FetchType.EAGER)
    private Set<User> children;

@Getter
@Setter
@EqualsAndHashCode
@AllArgsConstructor
@NoArgsConstructor
public class UserCompositeId implements Serializable {
    private Integer id;
    private String firstName;
    private String lastName;

SELECT * 
FROM dbo.user ur1 LEFT OUTER JOIN dbo.user ur2 ON ur1.first_name=ur2.first_name AND ur1.parent_id=ur2.id AND ur1.last_name=ur2.last_name 
WHERE ur1.first_name='First Name' AND ur1.id=130 AND ur1.last_name='Last Name'

我通过手动运行它来确保请求不会返回数据库中的任何内容，但发现如果我将id更改为parent_id，它将返回数据，因此，@joincolumn块中可能存在错误

Answer 1

您需要使用@notfind(action=notfoundaction.ignore)。如果没有记录，那么它将为其分配null。

    @ManyToOne
    @JoinColumn(name = "parent_id", referencedColumnName = "id", insertable = false, updatable = false)
    @JoinColumn(name = "first_name", referencedColumnName = "first_name", insertable = false, updatable = false)
    @JoinColumn(name = "last_name", referencedColumnName = "last_name", insertable = false, updatable = false)
    @NotFound(action=NotFoundAction.IGNORE)
    private User parent;