Question

我有2个实体，通过@OneToOne注释连接。首先是我的课程，以便更好地理解：

第二实体：

@Table(name = "REASON_FOR_CLIENT_CHEQUE_PAYMENT_REVERSAL")
@Entity
public class ReversalReason implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 3338809410372872259L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer code;

    private boolean tax;
    private boolean currency;
    private boolean amountChange;
    private boolean locationChange;
    private boolean recipient;
    private boolean period;

    public ReversalReason() {

    }
}

基础实体：

@Table(name = "CLIENT_CHEQUE_PAYMENT")
@Entity
public class ClientChequePayment extends BaseDomainObject implements Serializable {
    /** Serial version UID */
    private static final long serialVersionUID = -1988633355L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer code;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "code", nullable = true)
    private ReversalReason reasonForReversal;

    @Column(nullable = true, length = 50)
    private String proposeReversalUser;
    @Column(length = 50, unique = true)
    private String displayCode;
    @Column(length = 50)
    private String originalEntry;

    private PaymentStatus originalPaymentStatus;

我确实省略了一些字段，否则代码会太多。现在让我们来解决问题：

在我的计划中，我希望能够通过调用reasonForReversal设置ClientChequePayment的字段session.update(clientChequePayment);。我在调用update之前检查了字段是否已设置。问题是，hibernate确实为ReversalReason创建了一个条目，但它没有在ReversalReason条目中将ClientChequePayment的PK设置为FK。因此，我可以为1 ReversalReason创建多个ClientChequePayment enries。

我的地图是否正确（我无需通过ClientChequePayment访问ReversalReason，反之亦然）？如果不需要映射是双向的吗？

Answer 1

继续发表评论。

问题是，您需要一个具有REASON_FOR_CLIENT_CHEQUE_PAYMENT_REVERSAL外键的列。

意思是，您的表格CLIENT_CHEQUE_PAYMENT需要REASON_FOR_CLIENT_CHEQUE_PAYMENT_REVERSAL的外键，例如id_reversal_reason，然后您可以这样做：

@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "id_reversal_reason", nullable = true)
private ReversalReason reasonForReversal;

连接列位于源表的拥有表上。

来自name javadocs @JoinColumn的摘录：

(Optional) The name of the foreign key column.
 * The table in which it is found depends upon the
 * context.
 * <ul>
 * <li>If the join is for a OneToOne or ManyToOne
 *  mapping using a foreign key mapping strategy,
 * the foreign key column is in the table of the
 * source entity or embeddable.

Hibernate创建条目但不在@OneToOne中设置FK

1 个答案: