SQL 尝试持久化实体时，具有相同标识符值的不同对象已与会话关联
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/13762713/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
提示：将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间：2020-09-01 12:30:10 来源:igfitidea点击:
a different object with the same identifier value was already associated with the session when trying to persist entity
提问by user1767476
I have a slight problem that I don't know how to solve. Could you help me please? When I am trying to persist entity I get next exception:
我有一个小问题，我不知道如何解决。请问你能帮帮我吗？当我尝试持久化实体时，出现下一个异常：
12:47:39,398 ERROR [org.black.dmitriy.entityHome.ScheduleHome] (http--127.0.0.1-8080-1) javax.persistence.EntityExistsException: a different object with the same identifier value was already associated with the session: [org.black.dmitriy.entity.Schedule#1]
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1333) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1289) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1295) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:859) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_04]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_04]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_04]
at java.lang.reflect.Method.invoke(Method.java:601) [rt.jar:1.7.0_04]
at org.jboss.seam.persistence.EntityManagerInvocationHandler.invoke(EntityManagerInvocationHandler.java:46) [jboss-seam.jar:2.3.0.Final]
at $Proxy81.persist(Unknown Source) at org.jboss.seam.framework.EntityHome.persist(EntityHome.java:84) [jboss-seam.jar:2.3.0.Final]
at org.black.dmitriy.entityHome.ConversationHome.tryPersist(ConversationHome.java:147) [ejb.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_04]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_04]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_04]
at java.lang.reflect.Method.invoke(Method.java:601) [rt.jar:1.7.0_04]
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.core.ConversationInterceptor.aroundInvoke(ConversationInterceptor.java:65) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.transaction.TransactionInterceptor.work(TransactionInterceptor.java:97) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.util.Work.workInTransaction(Work.java:61) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.transaction.TransactionInterceptor.aroundInvoke(TransactionInterceptor.java:91) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:186) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:104) [jboss-seam.jar:2.3.0.Final]
at org.black.dmitriy.entityHome.ScheduleHome_$$_javassist_seam_8.tryPersist(ScheduleHome_$$_javassist_seam_8.java) [ejb.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_04]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_04]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_04]
at java.lang.reflect.Method.invoke(Method.java:601) [rt.jar:1.7.0_04]
at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:335) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:348) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.parser.AstPropertySuffix.invoke(AstPropertySuffix.java:58) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.parser.AstValue.invoke(AstValue.java:96) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.component.UICommand.broadcast(UICommand.java:315) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158) [jboss-seam.jar:2.3.0.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:397) [jbossweb-7.0.13.Final.jar:]
at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50) [jboss-as-jpa-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) [jbossweb-7.0.13.Final.jar:]
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) [jbossweb-7.0.13.Final.jar:]
at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_04]
I use seam 2.3, hibernate. I have one insert statement in my import.sql file:
我使用seam 2.3，休眠。我的 import.sql 文件中有一个插入语句：
INSERT INTO Schedules (id, name, dayCount, lessonCount, firstTermSize, secondTermSize, subgroupSize) VALUES(1, '2012/2013', 5, 8, 9, 9, 18)
which inserts one enity into table Schedules.
它将一个实体插入到表 Schedules 中。
Then I create new Schedule entity throw web page using EntityHome
然后我使用 EntityHome 创建新的 Schedule 实体抛出网页
@Name("scheduleHome")
@Scope(ScopeType.CONVERSATION)
public class ScheduleHome extends ConversationHome<Schedule> {
private static final long serialVersionUID = 1L;
public ScheduleHome() {
}
@Override
protected boolean isUnique() {
Schedule schedule = getInstance();
Schedule foundSchedule = ScheduleDAO.instance().getByName(schedule.getName());
if ((foundSchedule != null) && (!foundSchedule.equals(schedule))) {
showExistsErrorMessage(getInstance().getName());
return false;
}
return true;
}
@Override
protected Schedule createInstance() {
return new Schedule();
}
@Override
public String getEditOutcome() {
return "scheduleEdit";
}
@Override
protected void prepareEntityForSaving() {
}
}
and the superclass
和超类
public abstract class ConversationHome<T> extends EntityHome<T> {
private static final long serialVersionUID = 1L;
private String parentView;
public boolean isParentViewExists() {
return parentView != null && parentView.length() > 0;
}
public void setParentView(String parentView) {
this.parentView = parentView;
}
public String getParentView() {
return parentView;
}
public abstract String getEditOutcome();
protected abstract void prepareEntityForSaving();
protected abstract boolean isUnique();
@Override
@Create
public void create() {
create(false);
}
protected void create(boolean createNestedConversation) {
Conversation conversation = Conversation.instance();
if (!createNestedConversation && conversation.isLongRunning()) {
getLog().debug("conversation already started, nested will not create(isLongRunning = #0, isNested = #1)", conversation.isLongRunning(), conversation.isNested());
} else {
conversation.begin(false, conversation.isLongRunning());
conversation.changeFlushMode(FlushModeType.MANUAL);
getLog().debug("create(isLongRunning = #0, isNested = #1, id = #2)", conversation.isLongRunning(), conversation.isNested(), conversation.getId());
}
super.create();
}
private boolean init(Long id) {
FacesContext context = FacesContext.getCurrentInstance();
setParentView(Pages.getViewId(context));
if (id != null) {
setId(id);
try {
getInstance();
getLog().debug("instance initialized #0", getInstance());
} catch (EntityNotFoundException e) {
getLog().error(e);
return false;
}
}
return true;
}
public String startEdit(Long id) {
getLog().debug("start editing #0", id);
if (init(id)) {
return getEditOutcome();
} else {
return cancel();
}
}
public String cancel() {
if (isManaged()) {
getEntityManager().refresh(getInstance());
}
return returnToParent();
}
@End
protected String returnToParent() {
if (isParentViewExists()) {
Conversation conversation = Conversation.instance();
getLog().debug("end conversation(id = #0, isLongRunning = #1, isNested = #2)",
conversation.getId(), conversation.isLongRunning(), conversation.isNested());
conversation.end(true);
return getParentView();
} else {
clearInstance();
return null;
}
}
public String tryPersist() {
if (isUnique()) {
try {
prepareEntityForSaving();
String outcome = persist();
if (!"failed".equals(outcome)) {
return returnToParent();
}
} catch (Exception e) {
getLog().error(getInstance(), e);
showSaveErrorMessage(e);
}
}
return "failed";
}
}
and when i try to persist it i get this exception. and message on web page
当我尝试坚持它时，我得到了这个例外。和网页上的消息
Save error with message: a different object with the same identifier value was already associated with the session: [org.black.dmitriy.entity.Schedule#1]
保存错误消息：具有相同标识符值的不同对象已与会话关联：[org.black.dmitriy.entity.Schedule#1]
It seams that hibernate set id property to 1, but I already have entity with id = 1, because I manually created it throw import.sql.
它接缝将 hibernate 设置 id 属性设置为 1，但我已经有了带有 的实体id = 1，因为我手动创建了它抛出 import.sql。
Here is my Schedule entity :
这是我的 Schedule 实体：
import java.util.ArrayList;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
@Entity
@Table(name = "Schedules")
public class Schedule {
@Id
@GeneratedValue
@Column(name = "id", nullable = false)
private Long id;
@NotNull
@Column(name = "name", nullable = false, length = 40)
private String name;
@Column(name = "dayCount")
private int dayCount = 5;
@Column(name = "lessonCount")
private int lessonCount = 8;
@Column(name = "firstTermSize")
private int firstTermSize = 9;
@Column(name = "secondTermSize")
private int secondTermSize = 9;
@Column(name = "subgroupSize")
private int subgroupSize = 18;
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, targetEntity = Faculty.class)
private List<Faculty> faculties = new ArrayList<>();
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, targetEntity = Building.class)
private List<Building> buildings = new ArrayList<>();
public Schedule() {
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getDayCount() {
return dayCount;
}
public void setDayCount(int dayCount) {
this.dayCount = dayCount;
}
public int getLessonCount() {
return lessonCount;
}
public void setLessonCount(int lessonCount) {
this.lessonCount = lessonCount;
}
public int getFirstTermSize() {
return firstTermSize;
}
public void setFirstTermSize(int firstTermSize) {
this.firstTermSize = firstTermSize;
}
public int getSecondTermSize() {
return secondTermSize;
}
public void setSecondTermSize(int secondTermSize) {
this.secondTermSize = secondTermSize;
}
public int getSubgroupSize() {
return subgroupSize;
}
public void setSubgroupSize(int subgroupSize) {
this.subgroupSize = subgroupSize;
}
public List<Faculty> getFaculties() {
return faculties;
}
public void setFaculties(List<Faculty> faculties) {
this.faculties = faculties;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((id == null) ? 0 : id.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof Schedule)) {
return false;
}
Schedule other = (Schedule) obj;
if (id == null) {
if (other.id != null) {
return false;
}
} else if (!id.equals(other.id)) {
return false;
}
return true;
}
@Override
public String toString() {
return this.name;
}
}
As you can see there is @GeneratedValue annotation on id property, so I think that hibernate should generate id himself and hibernate should know that there is entity in database with id = 1, and set id in new entity = 2. But Hibernate sets id in new entity to 1. Could you halp me please?
如您所见，id 属性上有@GeneratedValue 注释，所以我认为hibernate 应该自己生成id，hibernate 应该知道数据库中有id = 1 的实体，并在新实体中设置id = 2。但是Hibernate 设置了id在新实体到 1. 你能帮我吗？
回答by Sazzadur Rahaman
The problem was how hibernate generates your id's, it starts from 1. When it assigns 1 to an object before saving it into database, it sees a row with same id already exists in the database and causes the exception. The simple and natural solution of this problem is simply to restrict hibernate, so that it can not assign 1as an id to any object of the concerning class (in your case).
问题是 hibernate 如何生成你的id's，它从 1 开始。当它在将对象保存到数据库之前将 1 分配给一个对象时，它看到数据库中已经存在具有相同 id 的行并导致异常。这个问题的简单而自然的解决方案是简单地限制休眠，使其不能1作为 id分配给相关类的任何对象（在您的情况下）。
Solution for mySql:
mySql的解决方案：
If you are using mySql, you can create table manually and set the auto increment like:
如果您使用的是 mySql，您可以手动创建表并设置自动增量，如：
CREATE TABLE IF NOT EXISTS `testTable` (
`id` number(11) NOT NULL AUTO_INCREMENT,
...,
...,
...,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2; //assigning id by hibernate, will start from 2.
And in your domain class you can have id annotated like bellow:
在您的域类中，您可以像下面这样注释 id：
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ID")
public long getId() {
....
}
GenerationType.AUTOby default uses auto increment in mySql. and after setting AUTO_INCREMENT=2hibernate will start assigning id's from 2(hence 1is skipped).
GenerationType.AUTO默认情况下在 mySql 中使用自动增量。并且在设置AUTO_INCREMENT=2hibernate 后将开始分配 id 的来源2（因此1被跳过）。
Solution for Oracle:
甲骨文解决方案：
The same thing for oracle can be done if you restrict hibernate use a "sequence" and you set the initial point of the sequence as your wish. You can create a sequence to be start from 2and increment by 1like bellow:
如果您限制休眠使用“序列”并根据需要设置序列的初始点，则可以为 oracle 做同样的事情。您可以创建一个序列，以如下方式开始2和递增1：
create sequence idSequence
start with 2
increment by 1
maxvalue 9999999999999;
And you can specify your sequence to be used to generate id's of your domain class's object like bellow:
您可以指定用于生成域类对象的 id 的序列，如下所示：
@Id
@SequenceGenerator(name = "idGeneratorSeq", sequenceName = "idSequence")
@GeneratedValue(strategy = GenerationType.AUTO, generator = "idGeneratorSeq")
@Column(name = "ID")
public long getId() {
....
}
And your problem is sovled.
您的问题已解决。
回答by prageeth
Do the following steps before calling persist()method.
在调用persist()方法之前执行以下步骤。
First detach your current instance
首先分离您当前的实例
getEntityManager().detach(getInstance());
Now set its Idto null
现在将其设置Id为空
getInstance().setId(null);
Now persist
现在坚持
String outcome = persist();
