EclipseLink：本机查询 INSERT INTO 上的“不允许更新”

Question

自从从 EL 2.1 升级到 EclipseLink 2.5 后，我们在之前运行的代码上得到了 PersistenceException。 场景非常简单：我们有两个相同的表，唯一的区别是一个是另一个的“历史”版本。基本上，当我们确定某行不再更改时，我们将该行移至历史记录表。这意味着虽然 id 是在第一个表上生成的，但它是在历史表上“继承的”。以下是实体：

@Entity
@Table(name = "DOCUMENT")
public class Document implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private long id;
    // Some other fields
}

@Entity
@Table(name = "DOCUMENT_HISTORY")
public class DocumentHistory implements Serializable {
    @Id
    private long id;
    // Some other fields
}

为了将一行移动到历史表中，我们使用原生查询（因为有些列没有映射为实体类中的字段）：

String query = "INSERT INTO DOCUMENT_HISTORY SELECT * FROM DOCUMENT t WHERE t.id=?1";
Query updateQuery = entityManager.createNativeQuery(query);
updateQuery.setParameter(1, document.getId());
updateQuery.executeUpdate();

执行此查询时，有时会抛出此异常：

javax.persistence.PersistenceException: Exception [EclipseLink-7251] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): 
org.eclipse.persistence.exceptions.ValidationException
Exception Description: The attribute [id] of class [org.myc.entities.jpa.company.DocumentHistory] is mapped to a primary key column in the database. Updates are not allowed.
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:868)
    at org.eclipse.persistence.internal.jpa.QueryImpl.performPreQueryFlush(QueryImpl.java:963)
    at org.eclipse.persistence.internal.jpa.QueryImpl.executeUpdate(QueryImpl.java:296)
    at org.myc.utility.jpa.user.DocumentManager.toDocumentHistory(DocumentManager.java:141)
    at java.lang.Thread.run(Thread.java:662)
Caused by: Exception [EclipseLink-7251] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The attribute [id] of class [org.myc.entities.jpa.company.DocumentHistory] is mapped to a primary key column in the database. Updates are not allowed.
    at org.eclipse.persistence.exceptions.ValidationException.primaryKeyUpdateDisallowed(ValidationException.java:2548)
    at org.eclipse.persistence.mappings.foundation.AbstractDirectMapping.writeFromObjectIntoRowWithChangeRecord(AbstractDirectMapping.java:1257)
    at org.eclipse.persistence.internal.descriptors.ObjectBuilder.buildRowForUpdateWithChangeSet(ObjectBuilder.java:1768)
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.updateObjectForWriteWithChangeSet(DatabaseQueryMechanism.java:1030)
    at org.eclipse.persistence.queries.UpdateObjectQuery.executeCommitWithChangeSet(UpdateObjectQuery.java:84)
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.executeWriteWithChangeSet(DatabaseQueryMechanism.java:301)
    at org.eclipse.persistence.queries.WriteObjectQuery.executeDatabaseQuery(WriteObjectQuery.java:58)
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:899)
    at org.eclipse.persistence.queries.DatabaseQuery.executeInUnitOfWork(DatabaseQuery.java:798)
    at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWorkObjectLevelModifyQuery(ObjectLevelModifyQuery.java:108)
    at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWork(ObjectLevelModifyQuery.java:85)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2896)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1793)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1775)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1726)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitChangedObjectsForClassWithChangeSet(CommitManager.java:267)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsForClassWithChangeSet(CommitManager.java:192)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:138)
    at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:4196)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1441)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithPreBuiltChangeSet(UnitOfWorkImpl.java:1587)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.writeChanges(RepeatableWriteUnitOfWork.java:452)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:863)
    ... 5 more

有人遇到过同样的问题吗？为什么你认为这不会发生在所有行上，而只是其中一些行（没有明显的特定特征）？ 提前致谢， 卢克

P.S.：EL 对原生查询执行映射/查询验证是否正确？

Answer 1

好的，我发现了问题，并且与该查询完全无关，所以我仍然不知道为什么会在那里抛出异常。 问题在于，我们没有使用entityManager.find() 来获取新插入的历史记录行，而是创建了一个未附加到持久性上下文的 DocumentHistory 实例（具有相同的 ID），然后使用该实例执行其他操作。 希望它可以帮助某人。

Answer 2

如 JPA 2.0 规范中所述，executeUpdate() 执行更新或删除语句，因此不支持插入。

您可以使用 EntityManager（在事务中）通过持久化和刷新实体来将实体插入到底层数据库中。在您的特定情况下，一个虚拟示例可能如下所示：

// transaction starts
Document doc = em.find(Document.class, id);
DocumentHistory docHistory = new DocumentHistory(doc);
em.persist(docHistory);
// transaction ends

注意：您可以考虑使用EclipseLink's auditing 功能，而不是专有解决方案（这很好）：

EclipseLink 还支持完整的历史记录，它允许在镜像历史记录表中跟踪对数据库所做的所有更改的完整历史记录。