Java 使用@Inheritation JPA属性时插入顺序无效

Java 使用@Inheritation JPA属性时插入顺序无效,java,inheritance,jpa,jpa-2.0,eclipselink,Java,Inheritance,Jpa,Jpa 2.0,Eclipselink,我已经在DB2DB上调试了Eclipselink持久性提供程序。其中有3个表,简化定义如下: CREATE TABLE root ( id CHAR(32) NOT NULL PRIMARY KEY, rec_type VARCHAR(20) ); CREATE TABLE derived ( id CHAR(32) NOT NULL PRIMARY KEY, ... ); ALTER TABLE derived ADD CONSTRAINT fk_

我已经在DB2DB上调试了Eclipselink持久性提供程序。其中有3个表,简化定义如下:

CREATE TABLE root
(
    id       CHAR(32) NOT NULL PRIMARY KEY,
    rec_type VARCHAR(20)
);

CREATE TABLE derived
(
    id CHAR(32) NOT NULL PRIMARY KEY,
    ...
);
ALTER TABLE derived ADD CONSTRAINT fk_derived_to_root FOREIGN KEY (id) REFERENCES root(id);

CREATE TABLE secondary
(
    derived_id NOT NULL PRIMARY KEY,
    ...
);
ALTER TABLE secondary ADD CONSTRAINT fk_secondary_to_derived FOREIGN KEY (derived_id) REFERENCES derived(id);
下面列出了这些实体的Java实体类, 根实体:

@javax.persistence.Table(name = "ROOT")
@Entity
@DiscriminatorColumn(name = "REC_TYPE")
@Inheritance(strategy = InheritanceType.JOINED)
public class RootEntity {
    private String id;

    @javax.persistence.Column(name = "ID")
    @Id
    @GeneratedValue(generator = "system-uuid")
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    private String principalType;
    @Column(name = "PRINCIPAL_TYPE")
    public String getPrincipalType() {
        return principalType;
    }

    public void setPrincipalType(String principalType) {
        this.principalType = principalType;
    }
   ...
}
衍生实体:

@javax.persistence.Table(name = "DERIVED")
@Entity
@DescriminatorValue("DERIVED")
public class DerivedEntity extends RootEntity {
    private SecondaryEntity secondaryEntity;

    @OneToOne(mappedBy = "derived_id")
    public SecondaryEntity getSecondaryEntity() {
        return secondaryEntity;
    }

    public void setSecondaryEntity(SecondaryEntity secondaryEntity) {
        this.secondaryEntity = secondaryEntity;
    }
 ...
}
我在测试日志中没有看到派生表插入:

--INSERT INTO ROOT (ID, REC_TYPE) VALUES (?, ?)
    bind => [241153d01c204ed79109ce658c066f4c, Derived]
--INSERT INTO SECONDARY (DERIVED_ID, ...) VALUES (?, ...)
    bind => [241153d01c204ed79109ce658c066f4c, ...]
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.ibm.db2.jcc.am.fo: DB2 SQL Error: SQLCODE=-530, SQLSTATE=23503, SQLERRMC=SCHEM.SECONDARY.FK_SECONDARY_TO_DERIVED, DRIVER=3.57.82
所以问题是:为什么Eclipselink在插入到
次要
表之前不将新记录插入到
派生的
表中


另外,当没有辅助表(
ROOT
DERIVED
表)或没有使用继承(
DERIVED
表生成id)时,一切都正常工作。

对于继承,JPA假设相关表中的外键约束引用根表

您可以更改约束以引用根表,或者

使用描述符设置

descriptor.setHasMultipleTableConstraintDependecy(true);
或者

自定义OneToOneMapping,使其外键引用辅助表(JPA注释始终使其引用根表)

不过,请记录一个bug,因为JPA联接列应该允许您定义辅助表的外键


EclipseLink延迟插入到辅助表的原因是允许插入按表分组,以允许批量写入并避免数据库死锁。

如果指定辅助关系的CascadeType,是否会有所不同?@Deniz,CascadeType在此处无法按预期工作/谢谢。第一种方法对我有效。第二种方法导致“此描述符中不存在表[派生的]。”