Hibernate:找到具有给定标识符的多个行错误

Question

我正在使用spring 4.0.5和hibernate 4.3.5; 我正面临一个hibernate的错误,我无法弄清楚我错在哪里(因为我确定我错了).我有一个与自身相关的表,它代表一个Web树,每个根节点可以有几个子节点,所以我创建了这个类:

@DynamicUpdate
@Cache(region = "it.eng.angelo.spring.dao.hibernate.models.WebTree", usage = CacheConcurrencyStrategy.READ_WRITE)
@Entity
@Table(name = "MEDIA_GALL_TREE", indexes = {@Index(name = "NOME_FOLDER_IDX", columnList = "NOME_FOLDER")})
public class WebTree extends AbstractModel
{

    private static final long serialVersionUID = -4572195412018767502L;
    private long id;
    private String text;
    private boolean opened;
    private boolean disabled;
    private boolean selected;
    private Set<WebTree> children = new HashSet<WebTree>(0);
    private Set<Media> media = new HashSet<Media>(0);
    private WebTree father;
    private WcmDomain dominio;
    public WebTree()
    {
        super();
    }
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ID_FOLDER", unique = true, nullable = false)
    public long getId()
    {
        return id;
    }
    public void setId(long id)
    {
        this.id = id;
    }
    @Column(name = "NOME_FOLDER", nullable = false, unique=false)
    public String getText()
    {
        return text;
    }
    public void setText(String text)
    {
        this.text = text;
    }
    @Column(name = "OPENED_FOLDER")
    public boolean isOpened()
    {
        return opened;
    }
    public void setOpened(boolean opened)
    {
        this.opened = opened;
    }
    @Column(name = "DISABLED_FOLDER")
    public boolean isDisabled()
    {
        return disabled;
    }
    public void setDisabled(boolean disabled)
    {
        this.disabled = disabled;
    }
    @Column(name = "SELECTED_FOLDER")
    public boolean isSelected()
    {
        return selected;
    }
    public void setSelected(boolean selected)
    {
        this.selected = selected;
    }
    @OneToMany(mappedBy = "father", orphanRemoval = true, targetEntity = WebTree.class)
    public Set<WebTree> getChildren()
    {
        return children;
    }
    public void setChildren(Set<WebTree> children)
    {
        this.children = children;
    }
    @ManyToOne(targetEntity = WebTree.class)
    @JoinColumn(name = "ID_PADRE", nullable = true)
    public WebTree getFather()
    {
        return father;
    }
    public void setFather(WebTree father)
    {
        this.father = father;
    }
    @OneToOne
    @JoinColumn(name="ID_DOMINIO", nullable=false)
    public WcmDomain getDominio()
    {
        return dominio;
    }
    public void setDominio(WcmDomain dominio)
    {
        this.dominio = dominio;
    }
    @OneToMany( mappedBy = "folder", orphanRemoval = true, targetEntity = Media.class, cascade = { CascadeType.ALL })
    public Set<Media> getMedia()
    {
        return media;
    }
    public void setMedia(Set<Media> media)
    {
        this.media = media;
    }

}

正如你所看到的......这是一个非常简单的POJO类; 现在我创建了这个单元测试:

@Test
public void testLoadModifyTree()
{
    try
    {
        DetachedCriteria dc = DetachedCriteria.forClass(MediaGalleryTree.class);
        dc.setFetchMode("father", FetchMode.JOIN);
        dc.add(Property.forName("id").eq(4l));
        List<MediaGalleryTree> result = hibSvc.search(dc, IConstants.NO_PAGINATION, IConstants.NO_PAGINATION);
        for (MediaGalleryTree mediaGalleryTree : result)
        {
            logger.info(mediaGalleryTree.getId());
        }
    }
    catch (Exception e)
    {
        logger.error(e.getMessage(), e);
    }
}

好吧,我查了一下,在DB中我只有1张ID为4的记录; 好吧,当我执行此查询时,我收到以下错误:

18:48:43,123 ERROR [WcmHibernateDao] Errore nella ricerca con detached criteria DetachableCriteria(CriteriaImpl(it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree:this[][id=4])); More than one row with the given identifier was found: 2, for class: it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree
org.hibernate.HibernateException: More than one row with the given identifier was found: 2, for class: it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree
    at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:100)
    at org.hibernate.loader.entity.EntityLoader.loadByUniqueKey(EntityLoader.java:161)
    at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:2385)
    at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:767)
    at org.hibernate.type.EntityType.resolve(EntityType.java:505)
    at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:170)
    at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:144)
    at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1114)
    at org.hibernate.loader.Loader.processResultSet(Loader.java:972)
    at org.hibernate.loader.Loader.doQuery(Loader.java:920)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:354)
    at org.hibernate.loader.Loader.doList(Loader.java:2553)
    at org.hibernate.loader.Loader.doList(Loader.java:2539)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2369)
    at org.hibernate.loader.Loader.list(Loader.java:2364)
    at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:126)
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1682)
    at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:380)
    at it.eng.comi.spring.dao.WcmHibernateDao.searchEntity(WcmHibernateDao.java:140)
    at it.eng.comi.spring.service.impl.WcmRdbmsExtSvcImpl.search(WcmRdbmsExtSvcImpl.java:237)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    at com.sun.proxy.$Proxy45.search(Unknown Source)
    at it.eng.comi.test.ComiTests.testLoadModifyTree(ComiTests.java:578)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:233)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:176)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
18:48:43,135 ERROR [WcmRdbmsExtSvcImpl] Errore nella ricerca con deatchedCriteria DetachableCriteria(CriteriaImpl(it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree:this[][id=4])); Errore nella ricerca con detached criteria DetachableCriteria(CriteriaImpl(it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree:this[][id=4])); More than one row with the given identifier was found: 2, for class: it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree
it.eng.comi.exception.CoMiDbException: Errore nella ricerca con detached criteria DetachableCriteria(CriteriaImpl(it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree:this[][id=4])); More than one row with the given identifier was found: 2, for class: it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree
    at it.eng.comi.spring.dao.WcmHibernateDao.searchEntity(WcmHibernateDao.java:146)
    at it.eng.comi.spring.service.impl.WcmRdbmsExtSvcImpl.search(WcmRdbmsExtSvcImpl.java:237)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    at com.sun.proxy.$Proxy45.search(Unknown Source)
    at it.eng.comi.test.ComiTests.testLoadModifyTree(ComiTests.java:578)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:233)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:176)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.hibernate.HibernateException: More than one row with the given identifier was found: 2, for class: it.eng.comi.spring.dao.hibernate.models.MediaGalleryTree
    at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:100)
    at org.hibernate.loader.entity.EntityLoader.loadByUniqueKey(EntityLoader.java:161)
    at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:2385)
    at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:767)
    at org.hibernate.type.EntityType.resolve(EntityType.java:505)
    at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:170)
    at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:144)
    at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1114)
    at org.hibernate.loader.Loader.processResultSet(Loader.java:972)
    at org.hibernate.loader.Loader.doQuery(Loader.java:920)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:354)
    at org.hibernate.loader.Loader.doList(Loader.java:2553)
    at org.hibernate.loader.Loader.doList(Loader.java:2539)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2369)
    at org.hibernate.loader.Loader.list(Loader.java:2364)
    at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:126)
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1682)
    at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:380)
    at it.eng.comi.spring.dao.WcmHibernateDao.searchEntity(WcmHibernateDao.java:140)
    ... 43 more

执行代码时,hibernate打印这些查询:

Hibernate: 
    select
        this_.ID_FOLDER as ID_FOLDE1_7_2_,
        this_.UT_INS as UT_INS2_7_2_,
        this_.DT_INS as DT_INS3_7_2_,
        this_.DT_UPD as DT_UPD4_7_2_,
        this_.UT_UPD as UT_UPD5_7_2_,
        this_.DISABLED_FOLDER as DISABLED6_7_2_,
        this_.ID_DOMINIO as ID_DOMI10_7_2_,
        this_.ID_PADRE as ID_PADR11_7_2_,
        this_.OPENED_FOLDER as OPENED_F7_7_2_,
        this_.SELECTED_FOLDER as SELECTED8_7_2_,
        this_.NOME_FOLDER as NOME_FOL9_7_2_,
        wcmdomain2_.ID_DOMINIO as ID_DOMIN1_8_0_,
        wcmdomain2_.UT_INS as UT_INS2_8_0_,
        wcmdomain2_.DT_INS as DT_INS3_8_0_,
        wcmdomain2_.DT_UPD as DT_UPD4_8_0_,
        wcmdomain2_.UT_UPD as UT_UPD5_8_0_,
        wcmdomain2_.WCM_NOME_DOMINIO as WCM_NOME6_8_0_,
        mediagalle3_.ID_FOLDER as ID_FOLDE1_7_1_,
        mediagalle3_.UT_INS as UT_INS2_7_1_,
        mediagalle3_.DT_INS as DT_INS3_7_1_,
        mediagalle3_.DT_UPD as DT_UPD4_7_1_,
        mediagalle3_.UT_UPD as UT_UPD5_7_1_,
        mediagalle3_.DISABLED_FOLDER as DISABLED6_7_1_,
        mediagalle3_.ID_DOMINIO as ID_DOMI10_7_1_,
        mediagalle3_.ID_PADRE as ID_PADR11_7_1_,
        mediagalle3_.OPENED_FOLDER as OPENED_F7_7_1_,
        mediagalle3_.SELECTED_FOLDER as SELECTED8_7_1_,
        mediagalle3_.NOME_FOLDER as NOME_FOL9_7_1_ 
    from
        MEDIA_GALL_TREE this_ 
    inner join
        WCM_DOMAIN wcmdomain2_ 
            on this_.ID_DOMINIO=wcmdomain2_.ID_DOMINIO 
    left outer join
        MEDIA_GALL_TREE mediagalle3_ 
            on this_.ID_PADRE=mediagalle3_.ID_FOLDER 
    where
        this_.ID_FOLDER=?
Hibernate: 
    select
        mediagalle0_.ID_FOLDER as ID_FOLDE1_7_2_,
        mediagalle0_.UT_INS as UT_INS2_7_2_,
        mediagalle0_.DT_INS as DT_INS3_7_2_,
        mediagalle0_.DT_UPD as DT_UPD4_7_2_,
        mediagalle0_.UT_UPD as UT_UPD5_7_2_,
        mediagalle0_.DISABLED_FOLDER as DISABLED6_7_2_,
        mediagalle0_.ID_DOMINIO as ID_DOMI10_7_2_,
        mediagalle0_.ID_PADRE as ID_PADR11_7_2_,
        mediagalle0_.OPENED_FOLDER as OPENED_F7_7_2_,
        mediagalle0_.SELECTED_FOLDER as SELECTED8_7_2_,
        mediagalle0_.NOME_FOLDER as NOME_FOL9_7_2_,
        wcmdomain1_.ID_DOMINIO as ID_DOMIN1_8_0_,
        wcmdomain1_.UT_INS as UT_INS2_8_0_,
        wcmdomain1_.DT_INS as DT_INS3_8_0_,
        wcmdomain1_.DT_UPD as DT_UPD4_8_0_,
        wcmdomain1_.UT_UPD as UT_UPD5_8_0_,
        wcmdomain1_.WCM_NOME_DOMINIO as WCM_NOME6_8_0_,
        mediagalle2_.ID_FOLDER as ID_FOLDE1_7_1_,
        mediagalle2_.UT_INS as UT_INS2_7_1_,
        mediagalle2_.DT_INS as DT_INS3_7_1_,
        mediagalle2_.DT_UPD as DT_UPD4_7_1_,
        mediagalle2_.UT_UPD as UT_UPD5_7_1_,
        mediagalle2_.DISABLED_FOLDER as DISABLED6_7_1_,
        mediagalle2_.ID_DOMINIO as ID_DOMI10_7_1_,
        mediagalle2_.ID_PADRE as ID_PADR11_7_1_,
        mediagalle2_.OPENED_FOLDER as OPENED_F7_7_1_,
        mediagalle2_.SELECTED_FOLDER as SELECTED8_7_1_,
        mediagalle2_.NOME_FOLDER as NOME_FOL9_7_1_ 
    from
        MEDIA_GALL_TREE mediagalle0_ 
    inner join
        WCM_DOMAIN wcmdomain1_ 
            on mediagalle0_.ID_DOMINIO=wcmdomain1_.ID_DOMINIO 
    left outer join
        MEDIA_GALL_TREE mediagalle2_ 
            on mediagalle0_.ID_PADRE=mediagalle2_.ID_FOLDER 
    where
        mediagalle0_.ID_DOMINIO=?

这些是我的表记录:

id_folder; ut_ins; dt_ins; dt_upd; ut_upd; disabled_folder; opened_folder; selected_folder; nome_folder; id_dominio; id_padre
"1";"system";"2014-06-12 18:23:16.649";"2014-06-12 18:23:16.649";"system";FALSE;FALSE;FALSE;"Root 1";1;
"2";"system";"2014-06-12 18:23:16.662";"2014-06-12 18:23:16.662";"system";FALSE;FALSE;FALSE;"Root 2";2;
"4";"wpsAdmin";"2014-06-13 16:18:01.428";"2014-06-13 18:12:14.228";"wpsAdmin";FALSE;FALSE;FALSE;"Testina";2;2
"7";"wpsAdmin";"2014-06-13 17:33:05.575";"2014-06-13 17:33:10.275";"wpsAdmin";FALSE;FALSE;FALSE;"Angelo";2;2

愿有人告诉我哪里错了吗？在我看来,这一切都是正确的......欢迎任何提示

谢谢Angelo

请注意:如果我以这种方式改变我的POJO类方法getChildern,那么一切都很好:

@OneToMany( mappedBy = "father", targetEntity = WebTree.class, fetch=FetchType.EAGER)
public Set<WebTree> getChildren()
{
    return children;
}

但我想知道为什么会这样做？

谢谢Angelo

Answer 1

我org.hibernate.HibernateException: More than one row with the given identifier was found:对此问题有所了解,并且在StackOverflow上找不到任何帮助.解决问题需要一段时间,所以我在这里记录解决方案.我正在使用JPA/Hibernate和Spring Data.

首先,这不是由数据库中的重复行引起的,因为显然不可能有重复的主键.相反,这是由Hibernate查找一个对象引起的,并急切地用LEFT OUTER JOIN填充一对一的关系.Hibernate假设一行会返回,但是有两个回来,因为有两个对象与一对一关系相关联.

这是我的对象的简化版本:

@Entity
@Table(name = "plate")
public class Plate {
    private static final long serialVersionUID = 1L;

    @Id
    @SequenceGenerator(name="test_seq", sequenceName="test_seq")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "test_seq")
    @Column(name = "id")
    private Long id;

    @Version
    @Column(name = "object_version")
    private long objectVersion;

    @Column(name = "name")
    private String name;

    @OneToOne(mappedBy = "plate")
    private Sheet sheet;

    public Sheet getSheet() {
        return sheet;
    }

    public void setSheet(Sheet sheet) {
        if (this.sheet != null) {
            this.sheet.setPlate(null);
        }

        this.sheet = sheet;
        sheet.setPlate(this);
    }
}


@Entity
@Table(name = "sheet")
public class Sheet {
    private static final long serialVersionUID = 1L;

    @Id
    @SequenceGenerator(name="test_seq", sequenceName="test_seq")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "test_seq")
    @Column(name = "id")
    private Long id;

    @Version
    @Column(name = "object_version")
    private long objectVersion;

    @Column(name = "sheet_name")
    private String sheetName;

    @OneToOne
    @JoinColumn(name = "plate_id")
    private Plate plate;

    public Plate getPlate() {
        return plate;
    }

    // Do not use. Use Plate.setSheet() instead
    void setPlate(Plate plate) {
        this.plate = plate;
    }
}

问题在于Plate和Sheet之间的@OneToOne关系.我最初不想删除孤立表.在我的代码中,我通过id查找了一个Plate并添加了一个新的Sheet.这删除了原始工作表中的"工具与工作表"关系.当我提交事务时,我假设JPA会保存所有修改过的对象(Plate,原始Sheet和新Sheet).

这不是真的!JPA显然通过从最初加载的对象(Plate)向下走层次来找到修改过的对象,并且它错过了现在孤立的原始Sheet被修改的事实.这意味着原始Sheet的sheet.plate_id列未在数据库中清除.换句话说,我打破了他们在数据模型中的关系,但它无法保存到数据库中.所以下次我尝试加载时,Hibernate会运行如下查询:

select
    plate1_.id as id1_19_12_, 
    plate1_.object_version as object_v2_19_12_, 
    plate1_.name as name3_19_12_, 
    sheet2_.id as id1_39_12_, 
    sheet2_.object_version as object_v2_39_12_, 
    sheet2_.sheet_name as sheet_nam2_39_12_, 
    sheet2_.plate_id as plate_id4_39_12_, 
from 
    plate plate1_
    left outer join sheet sheet2_ on plate1_.id = sheet2_.plate_id
where 
    plate1_.id=?

这会在结果集中返回2行并产生此错误:

org.hibernate.HibernateException: More than one row with the given identifier was found: 10045, for class: com.example.Plate

这是骗人的:在数据库中只有一个具有该id的Plate行,但是有两个Sheets链接到它.

解决方案:似乎我有两个选择:在一对一关系中全部级联并删除orphan,或者每次我删除与Plate的关系时,显式调用我的存储库类来查找并保存原始工作表.我选择了第一个选择并将其添加到板类中:

@OneToOne(mappedBy = "plate", cascade = CascadeType.ALL, orphanRemoval = true)
private Sheet sheet;

这解决了这个问题.

Answer 2

对不起; 这是我的错误......在我的实体类中,我错误地将关系映射为oneToOne; 相反,它是oneToMany :)现在一切都很好..... 这是我的新实体类:

@DynamicUpdate
@Cache(region = "it.eng.angelo.spring.dao.hibernate.models.MediaGalleryTree", usage = CacheConcurrencyStrategy.READ_WRITE)
@Entity
@Table(name = "MEDIA_GALL_TREE", indexes = {@Index(name = "NOME_FOLDER_IDX", columnList = "NOME_FOLDER")})
public class MediaGalleryTree extends AbstractModel
{

    private static final long serialVersionUID = -4572195412018767502L;
    private long id;
    private String text;
    private boolean opened;
    private boolean disabled;
    private boolean selected;
    private Set<MediaGalleryTree> children = new HashSet<MediaGalleryTree>(0);
    private Set<FedoraCommonsEntity> media = new HashSet<FedoraCommonsEntity>(0);
    private MediaGalleryTree father;
    private WcmDomain dominio;
    public MediaGalleryTree()
    {
        super();
    }
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ID_FOLDER", unique = true, nullable = false)
    public long getId()
    {
        return id;
    }
    public void setId(long id)
    {
        this.id = id;
    }
    @Column(name = "NOME_FOLDER", nullable = false, unique=false)
    public String getText()
    {
        return text;
    }
    public void setText(String text)
    {
        this.text = text;
    }
    @Column(name = "OPENED_FOLDER")
    public boolean isOpened()
    {
        return opened;
    }
    public void setOpened(boolean opened)
    {
        this.opened = opened;
    }
    @Column(name = "DISABLED_FOLDER")
    public boolean isDisabled()
    {
        return disabled;
    }
    public void setDisabled(boolean disabled)
    {
        this.disabled = disabled;
    }
    @Column(name = "SELECTED_FOLDER")
    public boolean isSelected()
    {
        return selected;
    }
    public void setSelected(boolean selected)
    {
        this.selected = selected;
    }
    @OneToMany( mappedBy = "father", orphanRemoval = true, 
                targetEntity = MediaGalleryTree.class)
    public Set<MediaGalleryTree> getChildren()
    {
        return children;
    }
    public void setChildren(Set<MediaGalleryTree> children)
    {
        this.children = children;
    }
    @ManyToOne(targetEntity = MediaGalleryTree.class)
    @JoinColumn(name = "ID_PADRE", nullable = true)
    public MediaGalleryTree getFather()
    {
        return father;
    }
    public void setFather(MediaGalleryTree father)
    {
        this.father = father;
    }
    @ManyToOne(targetEntity = WcmDomain.class, cascade={CascadeType.ALL})
    @JoinColumn(name="ID_DOMINIO", nullable=false)
    public WcmDomain getDominio()
    {
        return dominio;
    }
    public void setDominio(WcmDomain dominio)
    {
        this.dominio = dominio;
    }
    @OneToMany( mappedBy = "folder", orphanRemoval = true, 
            targetEntity = Media.class, cascade = { CascadeType.ALL })
    public Set<FedoraCommonsEntity> getMedia()
    {
        return media;
    }
    public void setMedia(Set<FedoraCommonsEntity> media)
    {
        this.media = media;
    }

}

安杰洛

Answer 3

如果您@OneToOne的类中有映射，则将获取类型更新为 LAZY。因为默认情况下OneToOne 的获取类型是 EAGER，所以当我们获取主类（WebTree）类的对象时，它将获取OneToOne映射类的对象，因此当休眠映射该对象时，它会抛出异常。简而言之，如果您有OneToOne映射，则将其替换为@OneToOne(fetch = FetchType.LAZY).

Answer 4

上述解决方案都不适合我的情况。我只能通过将双向一对一关系更改为单向一对一关系来使其发挥作用。

Answer 5

我遇到了同样的问题，我还将映射从 OneToOne 映射更改为 OneToMany 映射。之前，我错误地将映射定义为 OneToOne。现在它可以正常工作了。

老的

@OneToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY)
    @JoinColumn(name="appointmentId", nullable=false, insertable=false, updatable=false)
    private Appointment appointment;

当前的

@ManyToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY)
    @JoinColumn(name="appointmentId", nullable=false, insertable=false, updatable=false)
    private Appointment appointment;