Question

问候SO社区

我遇到了Hibernate JPA的问题：每当我调用entityManger.merge(entity)时，Hibernate都会尝试插入它。我从OpenJPA迁移到正常工作的地方，但无论我做什么，我都无法工作。

我一直在搜索SO和Google以寻找问题的解决方案，或者至少是指向正确方向的东西，没有运气。最接近我的问题的帖子尚未得到解答：entitymanager merge insert instead of update JPA Hibernate

我正在尝试插入与Organization实体具有单向@OneToOne关系的实体User。我添加了Casecade.Persist，因此User实体仅在创建/保留Organization时受到影响。持久化操作按预期工作。但是，正如之前提到的，merge不能按预期工作，而是尝试持久/插入。

有人可以帮我解决这个问题吗？

我想只使用JPA Hibernate并远离Hibernate特定的实现，以防我需要迁移到另一个JPA提供程序。

环境：

这是 Maven 项目，我正在使用 Wildfly 10

以下是我的代码：

我使用MappedSuperClass作为常用的SQL字段：

@MappedSuperclass
public abstract class BaseEntity implements Serializable{
    protected static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    protected Long id;

    //[UPDATE] I omitted the version field thinking it wasn't relevant, but now I believe this is the root of my problem. If I remove this field merge works as expected.
    @Version
    Long version
    // getters and setters
}

我想插入的实体：

@Entity
public class Organization extends BaseEntity{

    @Column
    private String name;

    @Column
    private String description;

    @OneToOne(cascade = CascadeType.PERSIST)
    @JoinColumn(unique = true, insertable = true)
    private User user;

    // getters and setters
}

User实体：

@Entity
public class User extends BaseEntity implements Serializable {
    private static final long serialVersionUID = 1L;

    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 100)
    private String username;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 256)
    private String password;
    @Size(max = 45)
    private String firstName;
    @Size(max = 45)
    private String lastName;

    //getters and setters

}

我尝试在JAX-RS休息方法中合并实体：

@Path("{id}")
@PUT
@Consumes("application/json")
@Produces("application/json")
public Organization edit(Organization entity,
                         @PathParam("id") Long id) {
    //Omitting how I got the userId as it is not relevant to the situation at hand
    entity.setUser(entityManager.find(User.class, userId));
    super.edit(entity);

    return entity;
}

注意：

上面的实体对象，我在请求中作为JSON对象传递并由Jackson编组，包含所有必需的字段， [尤其是主键（id）] 。
两个实体和MappedSuperClass都在persistence.xml

我在hibernate.show_sql中启用了persistence.xml以查看发生了什么：

<property name = "hibernate.show_sql" value = "true" />

下面是我得到的异常的堆栈跟踪：

17:58:08,804 INFO  [stdout] (default task-4) Hibernate: insert into Organization (createdBy, lastUpdatedBy, version, description, name, user_id) values (?, ?, ?, ?, ?, ?)  
17:58:09,302 WARN  [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (default task-4) SQL Error: 1062, SQLState: 23000
17:58:09,303 ERROR [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (default task-4) Duplicate entry '1' for key 'UK_5lqexr38qf28ptx0lhuhqor9w'
17:58:09,401 ERROR [org.jboss.as.ejb3.invocation] (default task-4) WFLYEJB0034: EJB Invocation failed on component OrganizationFacadeREST for method public com.scholarjet.model.Organization com.scholarjet.service.OrganizationFacadeREST.edit(com.scholarjet.model.Organization,java.lang.Long): javax.ejb.EJBException: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not execute statement
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.handleExceptionInOurTx(CMTTxInterceptor.java:187)
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:277)
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:327)
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:239)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.invocationmetrics.WaitTimeInterceptor.processInvocation(WaitTimeInterceptor.java:43)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.security.SecurityContextInterceptor.processInvocation(SecurityContextInterceptor.java:100)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.interceptors.ShutDownInterceptorFactory$1.processInvocation(ShutDownInterceptorFactory.java:64)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:66)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.interceptors.AdditionalSetupInterceptor.processInvocation(AdditionalSetupInterceptor.java:54)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.ContextClassLoaderInterceptor.processInvocation(ContextClassLoaderInterceptor.java:64)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:356)
    at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:636)
    at org.jboss.invocation.AccessCheckingInterceptor.processInvocation(AccessCheckingInterceptor.java:61)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:356)
    at org.jboss.invocation.PrivilegedWithCombinerInterceptor.processInvocation(PrivilegedWithCombinerInterceptor.java:80)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
    at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:195)
    at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:185)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
    at org.jboss.as.ee.component.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:73)
    at com.scholarjet.service.OrganizationFacadeREST$$$view4.edit(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:436)
    at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:127)
    at org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
    at org.jboss.weld.bean.proxy.InjectionPointPropagatingEnterpriseTargetBeanInstance.invoke(InjectionPointPropagatingEnterpriseTargetBeanInstance.java:67)
    at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:100)
    at com.scholarjet.service.OrganizationFacadeREST$Proxy$_$$_Weld$EnterpriseProxy$.edit(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:139)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:295)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:249)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:236)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:395)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:202)
    at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221)
    at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
    at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
    at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
    at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
    at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
    at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
    at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
    at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
    at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
    at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
    at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284)
    at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
    at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
    at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
    at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
    at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not execute statement
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1608)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1171)
    at org.jboss.as.jpa.container.AbstractEntityManager.merge(AbstractEntityManager.java:565)
    at com.scholarjet.service.AbstractFacade.edit(AbstractFacade.java:32)
    at com.scholarjet.service.OrganizationFacadeREST.edit(OrganizationFacadeREST.java:110)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
    at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:82)
    at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.processInvocation(Jsr299BindingsInterceptor.java:93)
    at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.invocationmetrics.ExecutionTimeInterceptor.processInvocation(ExecutionTimeInterceptor.java:43)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.jpa.interceptor.SBInvocationInterceptor.processInvocation(SBInvocationInterceptor.java:47)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
    at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:83)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
    at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:52)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.component.pool.PooledInstanceInterceptor.processInvocation(PooledInstanceInterceptor.java:51)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:275)
    ... 84 more
Caused by: org.hibernate.exception.ConstraintViolationException: could not execute statement
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:59)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:109)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:95)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:207)
    at org.hibernate.dialect.identity.GetGeneratedKeysDelegate.executeAndExtract(GetGeneratedKeysDelegate.java:57)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:42)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2792)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3363)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:597)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:232)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:213)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:256)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:317)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:272)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:178)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:109)
    at org.hibernate.jpa.event.internal.core.JpaMergeEventListener.saveWithGeneratedId(JpaMergeEventListener.java:56)
    at org.hibernate.event.internal.DefaultMergeEventListener.saveTransientEntity(DefaultMergeEventListener.java:255)
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsTransient(DefaultMergeEventListener.java:235)
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:173)
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:69)
    at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:840)
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:822)
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:827)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1161)
    ... 116 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '1' for key 'UK_5lqexr38qf28ptx0lhuhqor9w'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
    at com.mysql.jdbc.Util.getInstance(Util.java:372)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3835)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3771)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2435)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2582)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2535)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1911)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2145)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2081)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2066)
    at org.jboss.jca.adapters.jdbc.WrappedPreparedStatement.executeUpdate(WrappedPreparedStatement.java:537)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:204)
    ... 138 more

[UPDATE]

在PUT请求中提交的JSON对象：

{
  "id": 1,
  "name": "2 My Org 1",
  "description": "2 Org 1 Description 1"
}

就toString输出而言，我没有覆盖（覆盖？）此对象的toString方法。所以现在它返回toString中的默认Object方法：

com.francisco.model.Organization@1

如果它有帮助，我在我调用super.edit(entity)的行中放置一个断点并运行调试器。这是entity：

的内容

我还应该注意super.edit(entity)只是打电话： entityManager.merge(entity)

Answer 1

我省略了认为它不相关的版本字段，但现在我相信这是我问题的根源。如果我删除此字段合并按预期工作。

这是因为@Version和优化锁定的工作方式。

我总是不希望将@Version属性暴露给外部世界，因为它允许一些外部事件在我需要OptimisiticLockException被修改的情况下强制更新，当同一行被修改时多个会议同时进行。

您要做的是利用传输对象模式并覆盖实际数据库对象顶部的传入数据：

@Path("{id}")
@PUT
@Consumes("application/json")
@Produces("application/json")
public Organization edit(OrganizationDTO dto,
                     @PathParam("id") Long id) {
  // lookup entity from database
  Organization org = entityManager.find( Organization.class, entity.getId() );
  // map changable values to the entity
  org.setName( dto.getName() );
  org.setDescription( dto.getDescription() );
  org.setUser( entityManager.find( User.class, userId ) );
  dto.setUser( org.getUser() );
  // merge changes
  entityManager.merge( org );
  // return dto
  return dto;
}

我相信你可以利用ObjectMapper来制作映射叠加层，而不必对其进行硬编码;我将此作为练习。

但问题的关键在于，您的问题的根源在于您尝试将传入的JSON数据视为完整的Organization对象，并尝试在数据库中更新它，而实际上它是＆＃39 ;部分数据。

如果您的初始JSON中提供了版本值，则假设提供的版本值与数据库中的值匹配，则hibernate将按预期使用合并。没有匹配的非空值会引发OptimisticLockException。

EntityManager合并插入新实体

1 个答案: