Java 使用JPA持久化时覆盖的字段

在测试模型的持久性时，我会覆盖一个属性。我正在运行以下测试：

@Test
public void objectTest() throws Exception {
   tester.testClass(AssetUpdateReserve.class);       
   Assert.assertEquals(tester.getResult().getErrors().size(), 0, "Errors found");   
}

我的AssetUpdateReserve实体：

@Entity
@Table(name = "ASSET_UPD_RESERVE")
public class AssetUpdateReserve implements Serializable {

    private static final long serialVersionUID = 6530799190088978893L;

    @EmbeddedId
    @AttributeOverrides({
            @AttributeOverride(name = "partitionId.assetSliceId", column = @Column(name = "PARTITION_ID")),
            @AttributeOverride(name = "partitionId.associatedKey", column = @Column(name = "PARTITION_ID_AK")),
            @AttributeOverride(name = "containerId.id", column = @Column(name = "CONTAINER_ID")),
            @AttributeOverride(name = "containerId.associatedKey", column = @Column(name = "CONTAINER_ID_AK")) })
    private AssetUpdateReserveIndex id;

    // Default JSON/JAXB constructor
    public AssetUpdateReserve() {
    }
}

根据这一点，我应该有一个具有四个属性的主键。但是，associatedKey中的相同名称会使其中一个属性被覆盖（在本例中，CONTAINER_ID_AK会覆盖PARTITION_AD_AK），从而使我的主键只有三个字段。 我试图对最后一个@AttributeOverride进行注释，这解决了问题，并且该表具有PARTITION\u ID\u AK列。然而，我不能简单地忽略容器ID

我的其他实体：

资产许可证

@Embeddable
public class AssetSliceId implements Serializable {
    private static final long serialVersionUID = 9065665917069565503L;

    public static final int MAX_VALUE = Integer.MAX_VALUE;

    @Column(name = "ASSET_SLICE_ID")
    private Integer assetSliceId;

    @Column(name = "ID_AK")
    private String associatedKey;

    public AssetSliceId() {
        super();
    }
}

AssetUpdateReserveIndex：

@Embeddable
public class AssetUpdateReserveIndex implements Serializable {
    private static final long serialVersionUID = 1349614023445826884L;

    @Embedded
    @AttributeOverrides({ @AttributeOverride(name = "assetSliceId", column = @Column(name = "SLICE_ID")),
            @AttributeOverride(name = "associatedKey", column = @Column(name = "SLICE_ID_AK")) })    
    private AssetSliceId partitionId;

    @Embedded
    private InstanceId containerId;

    // Default JSON/JAXB constructor
    public AssetUpdateReserveIndex(){
        super();
    }
}

实例ID

@Embeddable
public class InstanceId implements Serializable {
    private static final long serialVersionUID = -6620668219143108192L;

    @Column(name = "ID")
    private String id;

    @Column(name = "ID_AK")
    private String associatedKey;

    // Apenas para utilizacao TopLink / POF
    public InstanceId() {
    }
}

我的persistence.xlm文件：

    <?xml version="1.0" encoding="UTF-8"?>
    <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence 

http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
    <persistence-unit name="jpa-test" transaction-type="RESOURCE_LOCAL">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

        <class>package.persistencetester.model.jpa.attroverride.AssetSliceId</class>      <class>package.persistencetester.model.jpa.attroverride.AssetUpdateReserve</class>       <class>package.persistencetester.model.jpa.attroverride.AssetUpdateReserveIndex</class>       <class>package.persistencetester.model.jpa.attroverride.InstanceId</class      <class>package.persistencetester.model.jpa.attroverride.SubscriptionID</class>

            <properties>
            <!-- Default Login using Oracle for EclipseLink's internal connection pool -->

            <!--  HSQL -->
            <property name="javax.persistence.jdbc.driver" value="org.hsqldb.jdbcDriver"/>
            <property name="javax.persistence.jdbc.url" value="jdbc:hsqldb:hsql://localhost/persistencetesterdb"/>
            <property name="javax.persistence.jdbc.user" value="sa"/>
            <property name="javax.persistence.jdbc.password" value=""/>

            <property name="eclipselink.logging.thread" value="false" />
            <property name="eclipselink.logging.session" value="false" />
            <property name="eclipselink.logging.exceptions" value="false" />
            <property name="eclipselink.logging.timestamp" value="false" />
            <property name="eclipselink.logging.level" value="FINE" />
            </properties>
        </persistence-unit>
</persistence>

---

注意：在日志中，您可以看到创建表，primarykey只有3个属性，但在插入时，这四个属性是否都有呢在对象关系映射方面没有太多经验，但是如果您的问题是有两个同名的数据，我想您可以使用

@AssociationOverride

来显示一个链接，这是您想要的，我认为本页的以下部分可以帮助您：

    @Embedded  
@AttributeOverrides(  {  
    @AttributeOverride(name="pesoMaximoEnKg", column = @Column(name="pesoMaximoEnKgConductor")),  
}  
@AssociationOverrides({  
    @AssociationOverride(name="cinturon",joinColumns=@JoinColumn(name="cinturonConductor_id")),  
})  
Asiento asientoConductor;


@Embedded  
@AttributeOverrides(  {  
    @AttributeOverride(name="pesoMaximoEnKg", column = @Column(name="pesoMaximoEnKgCopiloto")),  
}  
@AssociationOverrides({  
    @AssociationOverride(name="cinturon",joinColumns=@JoinColumn(name="cinturonCopiloto_id")),  
})  
Asiento asientoCopiloto;

附言：这个页面是西班牙语的，但我认为谷歌翻译会做得很好。 如果不是您想要的或无法为您提供的，我将通知我删除。

根据“不支持在嵌入式id类中定义的关系映射”

因为

containerId

和

partitionId

都包含一个名为

associatedKey

的字段，并且它们不能映射到

@EmbeddedId

类中的单独实体，所以表不是用主键中的所有四个值创建的（因为它会看到两次

associatedKey

，并丢弃重复项）。

如果查看“展平的”

AssetUpdateReserveIndex

结构，同一属性名有两个映射（

associatedKey

），后者会覆盖前者。我希望EclipseLink会出现某种验证异常，但您在日志中看到的（3个属性用于create table，4个属性用于insert）可能表明它们没有完全覆盖此特定情况。简单的解决方案是更改其中一个冲突字段的名称

    @Embedded  
@AttributeOverrides(  {  
    @AttributeOverride(name="pesoMaximoEnKg", column = @Column(name="pesoMaximoEnKgConductor")),  
}  
@AssociationOverrides({  
    @AssociationOverride(name="cinturon",joinColumns=@JoinColumn(name="cinturonConductor_id")),  
})  
Asiento asientoConductor;


@Embedded  
@AttributeOverrides(  {  
    @AttributeOverride(name="pesoMaximoEnKg", column = @Column(name="pesoMaximoEnKgCopiloto")),  
}  
@AssociationOverrides({  
    @AssociationOverride(name="cinturon",joinColumns=@JoinColumn(name="cinturonCopiloto_id")),  
})  
Asiento asientoCopiloto;