在一个应用程序中，我使用 EclipseLink 2.4.1 和 Java Persistence 2.0.4。
我在嵌入式类中有一个 OneToOne 映射。一切正常，除了删除。当我尝试删除包含嵌入类的对象时，会发生以下异常。我检查了一下，我没有在代码中的某个地方自己调用嵌入对象上的 remove 。有谁知道如何避免这个错误或如何解决它？
Exception [EclipseLink-6002] (Eclipse Persistence Services - 2.4.1.v20121003-ad44345): org.eclipse.persistence.exceptions.QueryException
Exception Description: Aggregated objects cannot be written/deleted/queried independently from their owners.
Descriptor: [RelationalDescriptor(org.openlca.web.model.ProcessModelInfo --> [])]
Query: DeleteObjectQuery(org.openlca.web.model.ProcessModelInfo@77cc2975)
at org.eclipse.persistence.exceptions.QueryException.aggregateObjectCannotBeDeletedOrWritten(QueryException.java:240)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.prepare(ObjectLevelModifyQuery.java:205)
at org.eclipse.persistence.queries.DeleteObjectQuery.prepare(DeleteObjectQuery.java:327)
at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:614)
at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:575)
at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:820)
at org.eclipse.persistence.queries.DatabaseQuery.executeInUnitOfWork(DatabaseQuery.java:751)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWorkObjectLevelModifyQuery(ObjectLevelModifyQuery.java:108)
at org.eclipse.persistence.queries.DeleteObjectQuery.executeInUnitOfWorkObjectLevelModifyQuery(DeleteObjectQuery.java:119)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWork(ObjectLevelModifyQuery.java:85)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2875)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1602)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1584)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1535)
at org.eclipse.persistence.queries.DeleteObjectQuery.executeDatabaseQuery(DeleteObjectQuery.java:194)
at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:852)
at org.eclipse.persistence.queries.DatabaseQuery.executeInUnitOfWork(DatabaseQuery.java:751)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWorkObjectLevelModifyQuery(ObjectLevelModifyQuery.java:108)
at org.eclipse.persistence.queries.DeleteObjectQuery.executeInUnitOfWorkObjectLevelModifyQuery(DeleteObjectQuery.java:119)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWork(ObjectLevelModifyQuery.java:85)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2875)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1602)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1584)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1535)
at org.eclipse.persistence.internal.sessions.CommitManager.deleteAllObjects(CommitManager.java:334)
at org.eclipse.persistence.internal.sessions.CommitManager.deleteAllObjects(CommitManager.java:288)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1422)
at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.commitToDatabase(RepeatableWriteUnitOfWork.java:634)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithChangeSet(UnitOfWorkImpl.java:1509)
at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.commitRootUnitOfWork(RepeatableWriteUnitOfWork.java:266)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitAndResume(UnitOfWorkImpl.java:1147)
at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commitInternal(EntityTransactionImpl.java:84)
at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:63)
at org.project.ProcessDao.delete(ProcessDao.java:41)
相关的类片段如下所示（在 persistence.xml 中添加了 Process 和 LongText） - 尝试删除进程时发生错误：
实体类过程
@Entity
public class Process {
@Id
@GeneratedValue(strategy = GenerationType.TABLE, generator = "process_seq")
@Column(name = "id")
private long id;
....
@Embedded
private ProcessModelInfo modelInfo = new ProcessModelInfo();
....
}
嵌入式类 ProcessModelInfo
@Embeddable
public class ProcessModelInfo {
...
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name= "f_modelling_constants")
private LongText modellingConstants = new LongText();
...
}
实体类 LongText
@Entity
@Table(name = "tbl_long_texts")
public class LongText {
@Id
@GeneratedValue(strategy = GenerationType.TABLE, generator = "long_text_seq")
@Column(name = "id")
private long id;
@Lob
@Column(name = "text")
private String text;
....
}
ProcessDao.delete 方法如下所示：
@Override
public void delete(Process entity) throws Exception {
if (entity == null)
return;
EntityManager em = createManager();
try {
em.getTransaction().begin();
em.remove(em.merge(entity));
em.getTransaction().commit();
} finally {
em.close();
}
}