嵌套嵌入 - AttributeOverride來爲嵌入內嵌入

Question

我有課的錢這是一個@Embeddable

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

當我useit內部實體，一切工作正常多的時間。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; 
} 

上面的代碼完美地工作。

現在問題出現時，我有另一個@Embeddable，我想在其中有Money實例，並且@Embeddable多次被實體使用。例如：

1. 嵌入式

   @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. 實體

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

此代碼上面將不起作用。任何想法如何解決這個問題？

Answer 1

嗨，你必須使用@AttributeOverrides司法上，你必須再次覆蓋屬性，你已經在可嵌入ReportCostValues類中做了實體，希望下面的代碼是你正在尋找的。

@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; 




} 

希望這會有所幫助!!!!!