OneToOne JPA 关系与复合主键

Question

我有一个不起作用的双向 OneToOne 示例：

@Embeddable
public class SolicitudGUCDetalleId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", precision = 10, scale = 0, insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCDET")
public class SolicitudGUCDetalle implements Serializable {

  @EmbeddedId
  private SolicitudGUCDetalleId id;

  @OneToOne(fetch = FetchType.LAZY, mappedBy = "solicitudGUCDetalle")
  private SolicitudGUCEnvio solicitudGUCEnvio;

  ...
}

@Embeddable
public class SolicitudGUCEnvioId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCENV")
public class SolicitudGUCEnvio implements Serializable {


  @EmbeddedId
  private SolicitudGUCEnvioId id;

  @OneToOne(fetch = FetchType.LAZY)
  @PrimaryKeyJoinColumns({
      @PrimaryKeyJoinColumn(name = "IDLINEA", referencedColumnName = "IDLINEA"),
      @PrimaryKeyJoinColumn(name = "IDPEDIDO", referencedColumnName = "IDPEDIDO")})
  private SolicitudGUCDetalle solicitudGUCDetalle;

  ...
}

我已经阅读了有关该问题的信息，并且我有两种可能的方法来实现这种有效的关系。

1 - 对复合主键使用相同的类：

@Embeddable
public class SolicitudGUCId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", precision = 10, scale = 0, insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCDET")
public class SolicitudGUCDetalle implements Serializable {

  @EmbeddedId
  private SolicitudGUCId id;

  @OneToOne(fetch = FetchType.LAZY, mappedBy = "solicitudGUCDetalle")
  private SolicitudGUCEnvio solicitudGUCEnvio;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCENV")
public class SolicitudGUCEnvio implements Serializable {

  @EmbeddedId
  private SolicitudGUCId id;

  @OneToOne(fetch = FetchType.LAZY)
  @PrimaryKeyJoinColumns({
      @PrimaryKeyJoinColumn(name = "IDLINEA", referencedColumnName = "IDLINEA"),
      @PrimaryKeyJoinColumn(name = "IDPEDIDO", referencedColumnName = "IDPEDIDO")})
  private SolicitudGUCDetalle solicitudGUCDetalle;

  ...
}

2 - 切换到 @OneToMany 关系并将相关实体存储在一个集合中：

@Embeddable
public class SolicitudGUCDetalleId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", precision = 10, scale = 0, insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCDET")
public class SolicitudGUCDetalle implements Serializable {

  @EmbeddedId
  private SolicitudGUCDetalleId id;

  @OneToMany(fetch = FetchType.LAZY, mappedBy = "solicitudGUCDetalle")
  private Set<SolicitudGUCEnvio> solicitudes;

  ...
}

@Embeddable
public class SolicitudGUCEnvioId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCENV")
public class SolicitudGUCEnvio implements Serializable {

  @EmbeddedId
  private SolicitudGUCEnvioId id;

  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumns({
      @JoinColumn(name = "IDLINEA", referencedColumnName = "IDLINEA",
          nullable = false, insertable = false, updatable = false),
      @JoinColumn(name = "IDPEDIDO", referencedColumnName = "IDPEDIDO",
          nullable = false, insertable = false, updatable = false)})
  private SolicitudGUCDetalle solicitudGUCDetalle;

  ...
}

我想知道我是否可以按照我的第一个示例实现这种关系。 如果答案是否定的，我想知道为什么。

Answer 1

这似乎是一个“派生身份”； 所以你可以尝试对你的选项 1 稍作修改：

@Embeddable
public class SolicitudGUCId implements Serializable {

    @Column(name = "IDPEDIDO", insertable = false, updatable = false)
    @Size(max = 36)
    private String idPedido;

    @Column(name = "IDLINEA", precision = 10, scale = 0, insertable = false, updatable = false)
    private long idLinea;

    ...
}

@Entity
@Table(name = "TRIISOLIDGUCDET")
public class SolicitudGUCDetalle implements Serializable {

    @EmbeddedId
    private SolicitudGUCId id;

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "solicitudGUCDetalle")
    private SolicitudGUCEnvio solicitudGUCEnvio;

    ...
}

@Entity
@Table(name = "TRIISOLIDGUCENV")
public class SolicitudGUCEnvio implements Serializable {

    @EmbeddedId
    private SolicitudGUCId id;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumns({
        @JoinColumn(name = "IDLINEA", referencedColumnName = "IDLINEA"),
        @JoinColumn(name = "IDPEDIDO", referencedColumnName = "IDPEDIDO")})
    @MapsId
    private SolicitudGUCDetalle solicitudGUCDetalle;

    ...
}

需要注意的是SolicitudGUCEnvio.solicitudGUCDetalle与注释@MapsId和@JoinColumns （相对于@PrimaryKeyJoinColumns ）。

派生身份在JPA 2.2 规范的 2.4.1 节中讨论（通过示例）。

Answer 2

这是我一直在寻找的解决方案：

@Embeddable
public class SolicitudGUCDetalleId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", precision = 10, scale = 0, insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCDET")
public class SolicitudGUCDetalle implements Serializable {

  @EmbeddedId
  private SolicitudGUCDetalleId id;

  @OneToOne(fetch = FetchType.LAZY, mappedBy = "solicitudGUCDetalle")
  private SolicitudGUCEnvio solicitudGUCEnvio;

  ...
}

@Embeddable
public class SolicitudGUCEnvioId implements Serializable {

  @Column(name = "IDPEDIDO", insertable = false, updatable = false)
  @Size(max = 36)
  private String idPedido;

  @Column(name = "IDLINEA", insertable = false, updatable = false)
  private long idLinea;

  ...
}

@Entity
@Table(name = "TRIISOLIDGUCENV")
public class SolicitudGUCEnvio implements Serializable {


  @EmbeddedId
  private SolicitudGUCEnvioId id;

  @OneToOne(fetch = FetchType.LAZY)
  @JoinColumns({@JoinColumn(name = "IDLINEA", referencedColumnName = "IDLINEA"),
      @JoinColumn(name = "IDPEDIDO", referencedColumnName = "IDPEDIDO")})
  @MapsId
  private SolicitudGUCDetalle solicitudGUCDetalle;

  ...
}

@Brian Vosburgh，感谢您的帮助