“不存在具有给定标识符的行”尽管它确实存在 [英] "No row with the given identifier exists" although it DOES exist

问题描述

我使用Hibernate并获取

线程main中的异常org.hibernate.ObjectNotFoundException：不存在具有给定标识符的行：[＃271]

这个错误的奇怪之处在于，具有给定标识的对象存在于数据库中。我在应用程序的另一个运行中插入了有问题的记录。如果我在同一次运行（即同一个hibernate会话）中访问它，那么检索数据似乎没有问题。

仅仅因为它可能是映射的错误：

  public class ProblemClass implements Persistent {
 @ManyToOne（optional = false）
 private MyDbObject myDbObject; 
} 
 public class MyDbObject implements Persistent {
 @OneToMany（mappedBy =myDbObject）
 private List< ProblemClass> problemClasses; 
 @ManyToOne（可选= false）
私有ThirdClass thirdClass; 
} 
  

即使在哪里看，我也绝对不知道。任何提示高度赞赏！

只是澄清：
数据被插入到应用程序的另一个RUN中。这绝对是在数据库中，因为我可以在应用程序终止后通过SQL查询来查看它。 THAT之后，即再次启动应用程序时，我在数据库的FIRST查询中遇到了错误 - 不删除，不涉及回滚。

添加：
因为有人问，这里是获取数据的代码：

  public List< ProblemClass> getProblemClasses（）{
 Query query = session.createQuery（from ProblemClass）; 
返回query.list（）; 
 
 
 $ 
 
 
 
为了使它完整，下面是插入它的通用代码（在获取应用程序的另一个RUN之前）： 
 
 
  public void save（持久持久性）{
 session.saveOrUpdate持续性）; 
 
  
 
 
解决方案
尤里卡，我找到了！ 
 
 
 
问题如下： 
 
 
表中的数据 ThirdClass  code>没有正确保存。由于此数据是通过 
 
 
 可选= false 
   
 
 
 Hibernate创建了一个内部联接，从而为联接返回一个空的结果。因为数据在一个会话中执行（在缓存中我猜），所以没有任何问题。
 
 
 
 MySQL不强制执行外键完整性，因此不会抱怨插入损坏的数据。
 
 
解决方案：可选= true或正确插入数据。
 
I am using Hibernate and getting 

  
Exception in thread "main" org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [#271]
What is pretty weird about this error is, that the object with the given id exists in the database. I inserted the problematic record in another run of the application. If I access it in the same run (i.e. same hibernate session) there seem to be no problems retrieving the data.

Just because it could be a fault of the mapping:
public class ProblemClass implements Persistent {
  @ManyToOne(optional = false)
  private MyDbObject myDbObject;
}
public class MyDbObject implements Persistent {
  @OneToMany(mappedBy = "myDbObject")
  private List<ProblemClass> problemClasses;
  @ManyToOne(optional = false)
  private ThirdClass thirdClass;
}
I have absolutely no clue even where to look at. Any hints highly appreciated!

Just to clarify:
The data was inserted in another RUN of the application. It is definitely in the database, as I can see it via an SQL-Query after the application terminated. And after THAT, i.e. when starting the application again, I get the error in the FIRST query of the database -- no deletion, no rollback involved.

Addition:
Because it was asked, here is the code to fetch the data:
public List<ProblemClass> getProblemClasses() {
    Query query = session.createQuery("from ProblemClass");
    return query.list();
}
And just to make it complete, here is the generic code to insert it (before fetching in another RUN of the application):
public void save(Persistent persistent) {
    session.saveOrUpdate(persistent);
}

解决方案
Eureka, I found it!

The problem was the following:

The data in the table ThirdClass was not persisted correctly. Since this data was referenced from MyDbObject via
optional = false
Hibernate made an inner join, thus returning an empty result for the join. Because the data was there if executed in one session (in the cache I guess), that made no problems.

MySQL does not enforce foreign key integrity, thus not complaining upon insertion of corrupt data.

Solution: optional = true or correct insertion of the data.

                        
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