hibernate - Nested embeddable - 可嵌入的 AttributeOverride

Question

我有类 Money 这是一个@Embeddable

@Embeddable
public class Money implements Serializable, Comparable<Money> {
    @Column(name = "amount", precision = 15, scale = 2)
    private BigDecimal amount;
}

当我在实体内多次使用它时，一切正常。例如

@Entity
public class SomeEntity implements Serializable {

    @Embedded
    @AttributeOverride(name = "amount", column = @Column(name = "entry"))
    private Money entryValue;

    @Embedded
    @AttributeOverride(name = "amount", column = @Column(name = "leave"))
    private Money leaveValue;
}

上面的代码完美运行。

现在，当我有另一个 @Embeddable 我想在其中包含 Money 实例并且 @Embeddable 被实体多次使用时，就会出现问题。例子：

1. 可嵌入

   @Embeddable
   public class ReportCostValues implements Serializable {
   
       @Embedded
       @AttributeOverride(name = "amount", column = @Column(name = "covered_by_grant"))
       private Money coveredByGrant;
   
       @Embedded
       @AttributeOverride(name = "amount", column = @Column(name = "own_resources"))
       private Money foundedFromOwnResources;
   
       @Embedded
       @AttributeOverride(name = "amount", column = @Column(name = "personal_contribution"))
       private Money personalContribution;
   

2. 实体

    @Entity
    public class ReportCostEntity implements Identifiable<Long>, Serializable {
   
       @Id
       private Long id;
   
       @Embedded       
       private ReportCostValues contracted;
   
       @Embedded       
       private ReportCostValues current;
   
       @Embedded        
       private ReportCostValues previousReport;
   

上面的这段代码不起作用。任何想法如何解决这个问题？

Answer 1

嗨，您必须正确使用@AttributeOverrides，您必须在可嵌入类中完成的实体中再次覆盖属性ReportCostValues，希望下面的代码是您正在寻找的。

@Entity 
public class ReportCostEntity implements  Serializable {

    @Id
    private Long id;

    @Embedded   
    @AttributeOverrides( {
        @AttributeOverride(name="coveredByGrant.amount", column = @Column(name="contracted_coveredByGrant") ),
        @AttributeOverride(name="foundedFromOwnResources.amount", column = @Column(name="contracted_foundedFromOwnResources")),
        @AttributeOverride(name="personalContribution.amount", column = @Column(name="contracted_personalContribution"))
    } )
    private ReportCostValues contracted;

    @Embedded
    @AttributeOverrides( {
        @AttributeOverride(name="coveredByGrant.amount", column = @Column(name="current_coveredByGrant") ),
        @AttributeOverride(name="foundedFromOwnResources.amount", column = @Column(name="current_foundedFromOwnResources")),
        @AttributeOverride(name="personalContribution.amount", column = @Column(name="current_personalContribution"))
    } )
    private ReportCostValues current;

    @Embedded 
    @AttributeOverrides( {
        @AttributeOverride(name="coveredByGrant.amount", column = @Column(name="previousReport_coveredByGrant") ),
        @AttributeOverride(name="foundedFromOwnResources.amount", column = @Column(name="previousReport_foundedFromOwnResources")),
        @AttributeOverride(name="personalContribution.amount", column = @Column(name="previousReport_personalContribution"))
    } )
    private ReportCostValues previousReport;




} 

希望这可以帮助 ！！！！！