blocks|key|189712|text|这很可能是因为B对象引用的不是同一个Java+C对象实例。它们引用数据库中的同一行(即相同的主键)，但它们是它的不同副本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|189713|因此，正在发生的事情是，管理实体的Hibernate会话将跟踪哪个Java对象对应于具有相同主键的行。|189714|一种选择是确保引用同一行的对象B的实体实际上引用了C的相同对象实例。或者，关闭该成员变量的级联。这样，当B被持久化时，C就不是了。不过，您必须手动单独保存C。如果C是一个类型/类别表，那么这样做可能是有意义的。|189715|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

Most probably its because the B objects are not referring to the same Java C object instance. They are referring to the same row in the database (i.e. the same primary key) but they're different copies of it. 

So what is happening is that the Hibernate session, which is managing the entities would be keeping track of which Java object corresponds to the row with the same primary key.

One option would be to make sure that the Entities of objects B that refer to the same row are actually referring to the same object instance of C. Alternatively turn off cascading for that member variable. This way when B is persisted C is not. You will have to save C manually separately though. If C is a type/category table, then it probably makes sense to be that way.

blocks|key|189717|text|在调用update+query之前，可能没有设置对象的标识符。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|189718|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

you might not be setting the identifier of the object before calling update query.

blocks|key|189732|text|我偶然发现了这条消息，不过是用c#代码写的。不确定它是否相关(但完全相同的错误消息)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|189733|我使用断点调试代码，并在调试器处于断点时通过私有成员扩展了一些集合。在没有深入研究结构的情况下重新运行代码会使错误消息消失。似乎查看私有延迟加载集合的行为使得NHibernate加载了当时不应该加载的东西(因为它们是在私有成员中)。|189734|代码本身被包装在一个相当复杂的事务中，该事务可以更新大量记录和许多依赖项，作为该事务(导入过程)的一部分。|189735|希望能给其他遇到这个问题的人提供一个线索。|189736|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

Just came across this message but in c# code. Not sure if it's relevant (exactly the same error message though).

I was debugging the code with breakpoints and expanded some collections through private members while debugger was at a breakpoint. Having re-run the code without digging through structures made the error message go away. It seems like the act of looking into private lazy-loaded collections has made NHibernate load things that were not supposed to be loaded at that time (because they were in private members).

The code itself is wrapped in a fairly complicated transaction that can update large number of records and many dependencies as part of that transaction (import process).

Hopefully a clue to anyone else who comes across the issue.

blocks|key|2810494|text|使用以下命令将分配对象ID的任务从Hibernate转移到数据库：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2810495|<generator+class="native"/>|code-block|syntax|javascript|2810496|这为我解决了这个问题。|2810497|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Transfer the task of assigning the object ID from Hibernate to the database by using:

<pre class="lang-java prettyprint-override"><code>&lt;generator class="native"/&gt;
</code></pre>

This solved the problem for me.

blocks|key|190137|text|你只需要做一件事。运行session_object.clear()，然后保存新对象。这将清除会话(命名恰当)，并从会话中删除有问题的重复对象。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|190138|entityMap^0|B|M|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

You only need to do one thing. Run <code>session_object.clear()</code> and then save the new object. This will clear the session (as aptly named) and remove the offending duplicate object from your session.

blocks|key|2810528|text|解决上述问题的一种方法是覆盖hashcode()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2810529|同时在保存之前和之后刷新休眠会话。|2810530|getHibernateTemplate().flush();|code-block|syntax|javascript|2810531|将分离的对象显式设置为null也会有所帮助。|2810532|entityMap^0|E|A|0|0|0|B|4|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|U|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

One way to solve the above problem will be to override the <code>hashcode()</code>. 
Also flush the hibernate session before and after save. 

<pre><code>getHibernateTemplate().flush();
</code></pre>

Explicitly setting the detached object to <code>null</code> also helps.

blocks|key|2810556|text|将注释@GeneratedValue添加到您要插入的bean。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2810557|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Add the annotation
@GeneratedValue
to the bean you are inserting.

blocks|key|190219|text|我几天前就遇到了这个错误，我花了太多的时间来修复这个错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|190220|+public+boolean+save(OrderHeader+header)+{
++++Session+session+=+sessionFactory.openSession();


++++Transaction+transaction+=+session.beginTransaction();

++++try+{
++++++++session.save(header);

++++++++for+(OrderDetail+detail+:+header.getDetails())+{
++++++++++++session.save(detail);
++++++++}

++++++++transaction.commit();
++++++++session.close();

++++++++return+true;
++++}+catch+(HibernateException+exception)+{

++++++++exception.printStackTrace();
++++++++transaction.rollback();
++++++++return+false;
++++}
}|code-block|syntax|javascript|190221|在我收到这个错误之前，我没有提到OrderDetil对象上的ID生成类型。当不生成Orderdetails的id时，它将每个OrderDetail对象的Id保持为0。这就是#jbx所解释的。是的，这是最好的答案。这是一个如何发生的例子。|190222|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I had this error few days a go and I sped too many time on fixing this error. 

<pre><code> public boolean save(OrderHeader header) {
 Session session = sessionFactory.openSession();


 Transaction transaction = session.beginTransaction();

 try {
 session.save(header);

 for (OrderDetail detail : header.getDetails()) {
 session.save(detail);
 }

 transaction.commit();
 session.close();

 return true;
 } catch (HibernateException exception) {

 exception.printStackTrace();
 transaction.rollback();
 return false;
 }
}
</code></pre>

Before i get this error , I didn't have mentioned ID generation type on the OrderDetil Object. when without generating Orderdetails' id it keeps Id as 0 for every OrderDetail objects. this what #jbx explained. Yes it is the best answer. this one example how it happens.

blocks|key|2810713|text|只需将cascade设置为MERGE，就可以了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2810714|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Just set cascade to MERGE, that should do the trick.

blocks|key|3023406|text|我同意@Hemant+Kumar的观点，非常感谢。根据他的解决方案，我解决了我的问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3023407|例如：|3023408|@Test
public+void+testSavePerson()+{
++++try+(Session+session+=+sessionFactory.openSession())+{
++++++++Transaction+tx+=+session.beginTransaction();
++++++++Person+person1+=+new+Person();
++++++++Person+person2+=+new+Person();
++++++++person1.setName("222");
++++++++person2.setName("111");
++++++++session.save(person1);
++++++++session.save(person2);
++++++++tx.commit();
++++}
}|code-block|syntax|javascript|3023409|Person.java|3023410|public+class+Person+{
++++private+int+id;
++++private+String+name;

++++@Id
++++@Column(name+=+"id")
++++public+int+getId()+{
++++++++return+id;
++++}

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

++++@Basic
++++@Column(name+=+"name")
++++public+String+getName()+{
++++++++return+name;
++++}

++++public+void+setName(String+name)+{
++++++++this.name+=+name;
++++}

}|3023411|这段代码在我的应用程序中总是出错：A+different+object+with+the+same+identifier+value+was+already+associated+with+the+session，后来我发现我忘记了自动增加我的主键！|offset|length|style|CODE|BOLD|3023412|我的解决方案是在您的主键上添加以下代码：|3023413|@GeneratedValue(strategy+=+GenerationType.AUTO)|3023414|entityMap^0|0|0|0|0|0|H|2H|38|9|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|11|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|12|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|13|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|14|8|@$O|15|P|16|Q|R]|$O|17|P|18|Q|S]]|9|@]|A|$]]|$1|T|3|U|5|6|7|19|8|@]|9|@]|A|$]]|$1|V|3|W|5|F|7|1A|8|@]|9|@]|A|$G|H]]|$1|X|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|Y|$]]

I agree with @Hemant Kumar, thank you very much. According his solution, I solved my problem.

For example：

<pre><code>@Test
public void testSavePerson() {
 try (Session session = sessionFactory.openSession()) {
 Transaction tx = session.beginTransaction();
 Person person1 = new Person();
 Person person2 = new Person();
 person1.setName("222");
 person2.setName("111");
 session.save(person1);
 session.save(person2);
 tx.commit();
 }
}
</code></pre>

Person.java

<pre><code>public class Person {
 private int id;
 private String name;

 @Id
 @Column(name = "id")
 public int getId() {
 return id;
 }

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

 @Basic
 @Column(name = "name")
 public String getName() {
 return name;
 }

 public void setName(String name) {
 this.name = name;
 }

}
</code></pre>

This code always make mistake in my application:
<code>A different object with the same identifier value was already associated with the session</code>, later I found out that I forgot
to autoincrease my primary key! 

My solution is to add this code on your primary key:

<pre><code>@GeneratedValue(strategy = GenerationType.AUTO)
</code></pre>

blocks|key|192469|text|试着把你的查询代码放在前面。这解决了我的问题。例如，更改以下内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|192470|query1+
query2+-+get+the+error+
update|code-block|syntax|javascript|192471|要这样做：|192472|query2
query1
update|192473|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Try to place the code of your query before.
That fix my problem.
e.g. change this:

<pre><code>query1 
query2 - get the error 
update
</code></pre>

to this:

<pre><code>query2
query1
update
</code></pre>

blocks|key|2810804|text|找到Hibernate中的"Cascade“属性并将其删除。当您设置“级联”可用时，它将调用其他操作(保存、更新和删除)到另一个与相关类有关系的实体上。因此，将发生相同的身份值。这对我很管用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2810805|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Find the "Cascade" atribute in Hibernate and delete it. When you set "Cascade" available, it will call other operations (save, update and delete) on another entities which has relationship with related classes. So same identities value will be happened. 
It worked with me.

blocks|key|2810821|text|当我像这样插入一行时，我遇到了这个问题，因为主键生成是错误的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2810822|public+void+addTerminal(String+typeOfDevice,Map<Byte,Integer>+map)+{
++++++++//+TODO+Auto-generated+method+stub
++++++++try+{
++++++++++++Set<Byte>+keySet+=+map.keySet();
++++++++++++for+(Byte+byte1+:+keySet)+{
++++++++++++++++Device+device=new+Device();
++++++++++++++++device.setNumDevice(DeviceCount.map.get(byte1));
++++++++++++++++device.setTimestamp(System.currentTimeMillis());
++++++++++++++++device.setTypeDevice(byte1);
++++++++++++++++this.getHibernateTemplate().save(device);
++++++++++++}
++++++++++++System.out.println("hah");
++++++++}catch+(Exception+e)+{
++++++++++++//+TODO:+handle+exception
++++++++++++logger.warn("wrong");
++++++++++++logger.warn(e.getStackTrace()%2Be.getMessage());
++++++++}
}|code-block|syntax|javascript|2810823|我将id生成器类更改为identity。|2810824|<id+name="id"+type="int">
++++<column+name="id"+/>
++++<generator+class="identity"++/>
+</id>|2810825|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I met the problem because of the primary key generation is wrong,when I insert a row like this:

<pre><code>public void addTerminal(String typeOfDevice,Map&lt;Byte,Integer&gt; map) {
 // TODO Auto-generated method stub
 try {
 Set&lt;Byte&gt; keySet = map.keySet();
 for (Byte byte1 : keySet) {
 Device device=new Device();
 device.setNumDevice(DeviceCount.map.get(byte1));
 device.setTimestamp(System.currentTimeMillis());
 device.setTypeDevice(byte1);
 this.getHibernateTemplate().save(device);
 }
 System.out.println("hah");
 }catch (Exception e) {
 // TODO: handle exception
 logger.warn("wrong");
 logger.warn(e.getStackTrace()+e.getMessage());
 }
}
</code></pre>

I change the id generator class to identity

<pre><code>&lt;id name="id" type="int"&gt;
 &lt;column name="id" /&gt;
 &lt;generator class="identity" /&gt;
 &lt;/id&gt;
</code></pre>

blocks|key|190270|text|在我的例子中，只有flush()不起作用。我必须在flush()之后使用clear()。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|190271|public+Object+merge(final+Object+detachedInstance)
++++{
++++++++this.getHibernateTemplate().flush();
++++++++this.getHibernateTemplate().clear();
++++++++try
++++++++{
++++++++++++this.getHibernateTemplate().evict(detachedInstance);
++++++++}
}|code-block|syntax|javascript|190272|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In my case only flush() did not work. I had to use a clear() after flush().

<pre><code>public Object merge(final Object detachedInstance)
 {
 this.getHibernateTemplate().flush();
 this.getHibernateTemplate().clear();
 try
 {
 this.getHibernateTemplate().evict(detachedInstance);
 }
}
</code></pre>

blocks|key|190278|text|这意味着您正在尝试保存表中的多行，其中包含对同一对象的引用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|190279|检查您的实体类的id属性。|190280|@Id
private+Integer+id;|code-block|syntax|javascript|190281|至|190282|@Id
@GeneratedValue(strategy+=+GenerationType.IDENTITY)
@Column(unique+=+true,+nullable+=+false)
private+Integer+id;|190283|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

This means you are trying to save multiple rows in your table with the reference to the same object.

check your Entity Class' id property.

<pre><code>@Id
private Integer id;
</code></pre>

to

<pre><code>@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(unique = true, nullable = false)
private Integer id;
</code></pre>

blocks|key|189907|text|如果使用EntityRepository，则使用saveAndFlush而不是save|type|unstyled|depth|inlineStyleRanges|entityRanges|data|189908|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

if you use EntityRepository then use saveAndFlush instead of save

blocks|key|188167|text|如果在IDE中打开了一个表达式选项卡，该选项卡将在导致此异常的对象上进行hibernate+get调用。我正试着删除同样的对象。另外，我在delete调用上有一个断点，这似乎是发生这个错误所必需的。只需将另一个表达式选项卡设置为前面的选项卡，或者更改设置以使ide不会在断点处停止，就解决了这个问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|188168|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If left an expressions tab in my IDE open which was making a hibernate get call on the object causing this exception. I was trying to delete this same object. Also I had a breakpoint on the delete call which seems to be necessary to get this error to happen. Simply making another expressions tab to be the front tab or changing the setting so that the ide does not stop on breakpoints solved this problem.

blocks|key|3023653|text|确保您的实体具有与所有映射实体相同的层代类型|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3023654|例如:+UserRole|3023655|public+class+UserRole+extends+AbstractDomain+{

@Id
@GeneratedValue(strategy+=+GenerationType.AUTO)
private+Long+id;

private+String+longName;

private+String+shortName;

@Enumerated(EnumType.STRING)
private+CommonStatus+status;

private+String+roleCode;

private+Long+level;

@Column(columnDefinition+=+"integer+default+0")
private+Integer+subRoleCount;

private+String+modification;

@ManyToOne(fetch+=+FetchType.LAZY)
private+TypeOfUsers+licenseType;|code-block|syntax|javascript|3023656|}|3023657|模块：|3023658|public+class+Modules+implements+Serializable+{

@Id
@GeneratedValue(strategy+=+GenerationType.AUTO)
private+Long+id;

private+String+longName;

private+String+shortName;|3023659|3023660|具有映射的主实体|3023661|public+class+RoleModules+implements+Serializable{

@Id
@GeneratedValue(strategy+=+GenerationType.AUTO)
private+Long+id;

@ManyToOne(fetch+=+FetchType.LAZY,+cascade+=+CascadeType.MERGE)
private+UserRole+role;

@ManyToOne(fetch+=+FetchType.LAZY,+cascade+=+CascadeType.MERGE)
private+Modules+modules;

@Type(type+=+"yes_no")
private+boolean+isPrimaryModule;

public+boolean+getIsPrimaryModule()+{
++++return+isPrimaryModule;
}|3023662|3023663|entityMap^0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|11|8|@]|9|@]|A|$G|H]]|$1|O|3|J|5|6|7|12|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|13|8|@]|9|@]|A|$]]|$1|R|3|S|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|T|3|J|5|6|7|15|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|16|8|@]|9|@]|A|$]]]|V|$]]

Make Sure, your entity have same Generation Type with all Mapped Entitys

Ex : UserRole 

<pre><code>public class UserRole extends AbstractDomain {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String longName;

private String shortName;

@Enumerated(EnumType.STRING)
private CommonStatus status;

private String roleCode;

private Long level;

@Column(columnDefinition = "integer default 0")
private Integer subRoleCount;

private String modification;

@ManyToOne(fetch = FetchType.LAZY)
private TypeOfUsers licenseType;
</code></pre>

}

Module : 

<pre><code>public class Modules implements Serializable {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String longName;

private String shortName;
</code></pre>

}

Main Entity with Mapping

<pre><code>public class RoleModules implements Serializable{

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
private UserRole role;

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
private Modules modules;

@Type(type = "yes_no")
private boolean isPrimaryModule;

public boolean getIsPrimaryModule() {
 return isPrimaryModule;
}
</code></pre>

}

blocks|key|189985|text|除了前面的所有答案之外，如果您为您的类使用值对象而不在VO+Transformer类中设置id属性，那么在大型项目中解决此问题的可能方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|189986|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In addition to all the previous answers, a possible fix to this problem in a large scale project, if your using a Value Object for your classes don't set the id attribute in the VO Transformer class.

blocks|key|192563|text|只需提交当前事务。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|192564|currentSession.getTransaction().commit();|code-block|syntax|javascript|192565|现在您可以开始另一个事务，并在实体上执行任何操作|192566|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

just commit current transaction. 

<pre><code>currentSession.getTransaction().commit();
</code></pre>


now you can begin another Transaction and do anything on entity

blocks|key|2811109|text|另一种情况是，可以由自定义allocationSize生成相同的错误消息|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2811110|@Id
@Column(name+=+"idpar")
@GeneratedValue(strategy+=+GenerationType.SEQUENCE,+generator+=+"paramsSequence")
@SequenceGenerator(name+=+"paramsSequence",+sequenceName+=+"par_idpar_seq",+allocationSize+=+20)
private+Long+id;|code-block|syntax|javascript|2811111|没有匹配|2811112|alter+sequence+par_idpar_seq+increment+20;|2811113|可能会导致在插入期间进行约束验证(这很容易理解)，或者“具有相同标识符值的不同对象已经与会话关联”--这种情况不太明显。|2811114|entityMap^0|D|E|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|Y|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

Another case when same error message can by generated, custom <code>allocationSize</code>:
<pre><code>@Id
@Column(name = &quot;idpar&quot;)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = &quot;paramsSequence&quot;)
@SequenceGenerator(name = &quot;paramsSequence&quot;, sequenceName = &quot;par_idpar_seq&quot;, allocationSize = 20)
private Long id;
</code></pre>
without matching
<pre><code>alter sequence par_idpar_seq increment 20;
</code></pre>
can cause constraint validation during insert(that one is easy to understand) or ths &quot;a different object with the same identifier value was already associated with the session&quot; - this case was less obvious.

blocks|key|190483|text|出现这个问题的原因是，在您的子表中有不同的对象副本引用相同的原始数据，因此spring试图将您的对象视为新对象，但在保存它时会识别出有一个具有相同主键的原始数据。所以它给出了上面的错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|190484|这个问题的最佳解决方案是从DB+(您已经知道父对象的主键)加载整个对象(具有子实体的父实体)，然后从新对象(您试图保存)更新从DB加载的对象中的值，然后保存从具有新值的DB加载的对象。|190485|这将更新数据库中的值，而不会出现上述错误。|190486|PS-不需要更新in，因为它们已经存在于从DB加载的对象中，只更新需要更改的值|190487|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

The reason for this issue is you have have different copies of objects referring into same raw in your child table, so spring trying to treat your object as new object but while saving it identifies there is a raw with same primary key. So it gives above error.
Best solution for this issue is to load the whole object (parent entity with child entities) from DB (you already know the primary key of parent object), then update values in the object loaded from DB from your new object(which you were trying to save) and then save the object you loaded from the DB which has new values.
This will update your values in the DB without giving above error.
PS- Do not need to update ids as they already exist in object loaded from DB, update only the values need to be changed

blocks|key|2811210|text|如果您使用的是spring数据，另一种解决方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2811211|2811212|将对entityManager.persist()的调用替换为对repository.save()的调用，|unordered-list-item|offset|length|style|CODE|2811213|使用对repository.findBy...|2811214|的调用替换对entityManager.query().getResultList()等的调用|2811215|这样，弹簧数据就可以跟踪对象。它支持多个get和persist调用。|2811216|entityMap^0|0|0|2|N|W|H|0|3|K|0|6|11|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|S|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|T|8|@$F|U|G|V|H|I]|$F|W|G|X|H|I]]|9|@]|A|$]]|$1|J|3|K|5|E|7|Y|8|@$F|Z|G|10|H|I]]|9|@]|A|$]]|$1|L|3|M|5|6|7|11|8|@$F|12|G|13|H|I]]|9|@]|A|$]]|$1|N|3|O|5|6|7|14|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|Q|$]]

Another way to solve this if you are using spring data:
<ul>
<li>replace calls to <code>entityManager.persist()</code> with calls to <code>repository.save()</code>, and</li>
<li>replace calls to <code>entityManager.query().getResultList()</code> etc with calls to <code>repository.findBy...</code></li>
</ul>
This way, spring data keeps track of the objects. It enables multiple get and persist calls.

blocks|key|2811254|text|它不只是@Id尝试@Id+@GeneratedValue(策略=+GenerationType.AUTO)，它对我有效|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2811255|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

instead of just @Id
try
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
it worked for me

blocks|key|192654|text|在我的例子中，我有OneToOne关系，在用外键保存一行之后，尝试用相同的外键保存另一行时抛出相同的异常。这意味着需求不是OneToOne关系，而应该是ManyToOne。所以我把它改成了ManyToOne，它开始工作了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|192655|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In my case, I had OneToOne relationship and after saving one row with a foreign key, attempt to save another row with the same foreign key throw the same exception. It means that requirement was not OneToOne relationship, but should be ManyToOne. So I have changed it to ManyToOne and it started working.

I essentially have some objects in this configuration (the real data model is a bit more complex):

<ul>
<li>A has a many-to-many relationship with B. (B has <code>inverse="true"</code>)</li>
<li>B has a many-to-one relationship with C. (I have <code>cascade</code> set to <code>"save-update"</code>)</li>
<li>C is a kind of type/category table.</li>
</ul>

Also, I should probably mention that the primary keys are generated by the database on save.

With my data, I sometimes run into problems where A has a set of different B objects, and these B objects refer to the same C object.

When I call <code>session.saveOrUpdate(myAObject)</code>, I get a hibernate error saying: <code>"a different object with the same identifier value was already associated with the session: C"</code>. I know that hibernate can't insert/update/delete the same object twice in the same session, but is there some way around this? This doesn't seem like it would be that uncommon of a situation.

During my research of this problem, I have seen folks suggest the use of <code>session.merge()</code>, but when I do that, any "conflicting" objects get inserted into the database as blank objects with all values set to null. Clearly that isn't what we want.

[Edit] Another thing I forgot to mention is that (for architectural reasons beyond my control), each read or write needs to be done in a separate session.

Hibernate Error: a different object with the same identifier value was already associated with the session

数据库

调试器

Java

我基本上在这个配置中有一些对象(实际的数据模型稍微复杂一点)：类别A与B具有多对多关系。(B与inverse="true")B具有多对一关系。(我将cascade设置为"save-update")C是一种类型/类别表。另外，我可能应该提一下，主键是由数据库在保存时生成的。对于我的数据，我有时会遇到这样的问题:A有一组不...

问Hibernate错误:具有相同标识符值的不同对象已与该会话关联
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