用懒惰的行为在PK之间冬眠一个

Question

MyEntityImpl entity = em.find(MyEntityImpl.class, 1L);

我正在使用@OneToOne映射关系。我尝试了FetchType、Optional和@LazyToOne的几种组合，但到目前为止没有成功。

下面是MyEntity和MyEntityInfo类的代码（删除了额外的getter和setter）：

MyEntity（ID生成器是自定义序列生成器）：

@Entity
@Table(name = MyEntityImpl.TABLE_NAME)
public class MyEntityImpl {

    public static final String TABLE_NAME = "TMP_MY_ENTITY";

    @Id
    @GeneratedValue(strategy = GenerationType.TABLE, generator = "GEN_" +
            TABLE_NAME)
    @GenericGenerator(name = "GEN_" +
            TABLE_NAME, strategy = CoreIdGenerator.ID_GENERATOR, parameters = {
                    @Parameter(name = "tableName", value = TABLE_NAME) })
    @Column(name = "sid", nullable = false, unique = true)
    private Long               sid;

    @OneToOne(mappedBy = "myEntity", cascade = CascadeType.ALL, fetch = FetchType.LAZY, optional = true)
    @LazyToOne(LazyToOneOption.NO_PROXY)
    private MyEntityInfoImpl   info;

    @Column
    private String             field;

@Entity
@Table(name = MyEntityInfoImpl.TABLE_NAME)
public class MyEntityInfoImpl {
    public static final String TABLE_NAME = "TMP_MY_ENTITY_INFO";

    @Id
    @Column(name = "SID", nullable = false, unique = true)
    private Long               sid;

    @OneToOne(fetch = FetchType.EAGER, optional = false)
    @JoinColumn(name = "SID", referencedColumnName = "SID", insertable = false, updatable = false, nullable = false)
    private MyEntityImpl       myEntity;

    @Column(name = "INFO_FIELD")
    private String             infoField;

我已经设法使用@OneTomany和手动管理数据来做一些类似的事情，但这不是我想做的。但是，也欢迎使用@OneToOne或正确的设计模式来实现这一点的其他替代方案和信息。

PS：为SQL Server创建数据库表，如果您想尝试：

create table TMP_MY_ENTITY (SID NUMERIC(19,0) NOT NULL, FIELD VARCHAR(100));
go
ALTER TABLE TMP_MY_ENTITY ADD CONSTRAINT PK_TMP_MY_ENTITY PRIMARY KEY CLUSTERED (SID);
go

create table TMP_MY_ENTITY_INFO (SID NUMERIC(19,0) NOT NULL, INFO_FIELD VARCHAR(100));
go
ALTER TABLE TMP_MY_ENTITY_INFO ADD CONSTRAINT PK_TMP_MY_ENTITY_INFO PRIMARY KEY CLUSTERED (SID);
go

CREATE SEQUENCE SEQ_TMP_MY_ENTITY START WITH 1 INCREMENT BY 1 MINVALUE 1 CACHE 20;

alter table TMP_MY_ENTITY_INFO add constraint FK_TMP_MY_ENT_INFO_MY_ENT FOREIGN KEY (SID) references TMP_MY_ENTITY(SID);
go

insert into TMP_MY_ENTITY(SID, FIELD) VALUES (NEXT VALUE FOR SEQ_TMP_MY_ENTITY, 'Field 1');
insert into TMP_MY_ENTITY_INFO(SID, INFO_FIELD) VALUES ((SELECT MAX(SID) FROM TMP_MY_ENTITY), 'Info 1');

insert into TMP_MY_ENTITY(SID, FIELD) VALUES (NEXT VALUE FOR SEQ_TMP_MY_ENTITY, 'Field 2');
insert into TMP_MY_ENTITY_INFO(SID, INFO_FIELD) VALUES ((SELECT MAX(SID) FROM TMP_MY_ENTITY), 'Info 2');

insert into TMP_MY_ENTITY(SID, FIELD) VALUES (NEXT VALUE FOR SEQ_TMP_MY_ENTITY, 'Field 3 no info');

-- DELETE ALL

drop table TMP_MY_ENTITY_INFO;
drop table TMP_MY_ENTITY;
drop sequence SEQ_TMP_MY_ENTITY;

Answer 1

在遵循@sternk链接，并升级到Wildfly 19和Hibernate 5.4.14之后，通过使用@mapsid，它终于起作用了。

要使用的正确映射是：

我的实体：

public class MyEntityImpl {

    @OneToOne(mappedBy = "myEntity", cascade = CascadeType.REMOVE, fetch = FetchType.LAZY, optional = true)
    @JoinColumn(name = "SID")
    private MyEntityInfoImpl   info;

public class MyEntityInfoImpl {

    @OneToOne(fetch = FetchType.EAGER, optional = false)
    @MapsId
    @JoinColumn(name = "SID", referencedColumnName = "SID", insertable = false, updatable = false, nullable = false)
    private MyEntityImpl       myEntity;