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Java 使用jpa删除映射的元素

java jpa

Java 使用jpa删除映射的元素,java,jpa,eclipselink,one-to-many,Java,Jpa,Eclipselink,One To Many,几天来，我一直在想如何从映射中删除持久化元素。我发现线程有类似的问题，但最终没有一个能帮到我。 一切正常，添加和持久化元素，编辑和更新元素等等。除了删除元素。我有一个时间表，每个工作日有5张地图。下面是代码的基本部分 附表: @Entity public class Schedule extends JPAEntity implements Serializable { ... @OneToMany(mappedBy = "schedule", cascade = CascadeTyp

几天来，我一直在想如何从映射中删除持久化元素。我发现线程有类似的问题，但最终没有一个能帮到我。 一切正常，添加和持久化元素，编辑和更新元素等等。除了删除元素。我有一个时间表，每个工作日有5张地图。下面是代码的基本部分

附表:

@Entity
public class Schedule extends JPAEntity implements Serializable {

...
    @OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "id")
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> monday;

    @OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "id")
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> tuesday;

    @OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "id")
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> wednesday;

    @OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "id")
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> thursday;

    @OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "id")
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> friday;

    public boolean removeSubject(final int index, final SchoolSubject oldSubject) {
        final String day = oldSubject.getWeekday();

        switch (day) {
        case "Montag":
            return monday.remove(index, oldSubject);
        case "Dienstag":
            return tuesday.remove(index, oldSubject);
        case "Mittwoch":
            return wednesday.remove(index, oldSubject);
        case "Donnerstag":
            return thursday.remove(index, oldSubject);
        case "Freitag":
            return friday.remove(index, oldSubject);
        }
        return false;
    }
JPA实体：

@MappedSuperclass
@EntityListeners(JPAEntityListener.class)
public class JPAEntity {


    @Id
    @GeneratedValue
    private Long id;
因此，我在另一个逻辑类中的delete方法如下所示：

    @Override
    public void removeSubject(User user, Schedule schedule, SchoolSubject oldSubject) {
        if (schedule.removeSubject(oldSubject.getHourTime() - 1, oldSubject)) {
            schoolSubjectDAO.remove(oldSubject);
        }

        scheduleDAO.update(schedule);
        try {
            userDAO.update(user);
        } catch (final DuplicateUniqueFieldException e) {
            throw new UnexpectedUniqueViolationException(e);
        }
    }

 public void addSubject(User user, Schedule schedule, SchoolSubject subject)
            throws DateAlreadyOccupiedException {
        schedule.addSubject(subject.getHourTime() - 1, subject);
        scheduleDAO.update(schedule);
        try {
            userDAO.update(user);
        } catch (final DuplicateUniqueFieldException e) {
            throw new UnexpectedUniqueViolationException(e);
        }
    }

Severe:   javax.faces.el.EvaluationException: javax.ejb.EJBTransactionRolledbackException
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101)
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
    at javax.faces.component.UICommand.broadcast(UICommand.java:315)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at de.unibremen.st.gradelog.filter.AuthorizationFilter.doFilter(AuthorizationFilter.java:94)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: javax.ejb.EJBTransactionRolledbackException
    at com.sun.ejb.containers.BaseContainer.mapLocal3xException(BaseContainer.java:2342)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2123)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2044)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:220)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
    at com.sun.proxy.$Proxy613.update(Unknown Source)
    at de.unibremen.st.gradelog.persistence.__EJB31_Generated__UserDAO__Intf____Bean__.update(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:434)
    at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:127)
    at org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
    at org.jboss.weld.bean.proxy.InjectionPointPropagatingEnterpriseTargetBeanInstance.invoke(InjectionPointPropagatingEnterpriseTargetBeanInstance.java:67)
    at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:100)
    at de.unibremen.st.gradelog.persistence.UserDAO$Proxy$_$$_Weld$EnterpriseProxy$.update(Unknown Source)
    at de.unibremen.st.gradelog.businesslogic.ScheduleManager.addSubject(ScheduleManager.java:56)
    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:498)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
    at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
    at sun.reflect.GeneratedMethodAccessor86.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
    at com.sun.proxy.$Proxy605.addSubject(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:498)
    at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:434)
    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 de.unibremen.st.gradelog.businesslogic.IScheduleManager$1688850411$Proxy$_$$_Weld$EnterpriseProxy$.addSubject(Unknown Source)
    at de.unibremen.st.gradelog.controller.ScheduleBean.save(ScheduleBean.java:100)
    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:498)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
    at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
    at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
    ... 41 more
Caused by: javax.ejb.TransactionRolledbackLocalException: Exception thrown from bean
    at com.sun.ejb.containers.EJBContainerTransactionManager.checkExceptionClientTx(EJBContainerTransactionManager.java:666)
    at com.sun.ejb.containers.EJBContainerTransactionManager.postInvokeTx(EJBContainerTransactionManager.java:511)
    at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4566)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2074)
    ... 109 more
Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150605-31e8258): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID'  cannot accept a NULL value.
Error Code: 20000
Call: INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)
    bind => [2 parameters bound]
Query: DataModifyQuery(name="monday" sql="INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)")
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:879)
    at org.eclipse.persistence.internal.jpa.QueryImpl.performPreQueryFlush(QueryImpl.java:967)
    at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:207)
    at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:473)
    at de.unibremen.st.gradelog.persistence.UserDAO.getUserForUsername(UserDAO.java:227)
    at de.unibremen.st.gradelog.persistence.UserDAO.update(UserDAO.java:151)
    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:498)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
    at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
    at sun.reflect.GeneratedMethodAccessor86.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    ... 107 more
Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150605-31e8258): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID'  cannot accept a NULL value.
Error Code: 20000
Call: INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)
    bind => [2 parameters bound]
Query: DataModifyQuery(name="monday" sql="INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)")
    at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:902)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeNoSelect(DatabaseAccessor.java:964)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:633)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:560)
    at org.eclipse.persistence.internal.sessions.AbstractSession.basicExecuteCall(AbstractSession.java:2055)
    at org.eclipse.persistence.sessions.server.ClientSession.executeCall(ClientSession.java:306)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:242)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:228)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeNoSelectCall(DatasourceCallQueryMechanism.java:271)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeNoSelect(DatasourceCallQueryMechanism.java:251)
    at org.eclipse.persistence.internal.queries.StatementQueryMechanism.executeNoSelect(StatementQueryMechanism.java:118)
    at org.eclipse.persistence.queries.DataModifyQuery.executeDatabaseQuery(DataModifyQuery.java:85)
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:904)
    at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3267)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1857)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1839)
    at org.eclipse.persistence.mappings.ManyToManyMapping.insertAddedObjectEntry(ManyToManyMapping.java:630)
    at org.eclipse.persistence.mappings.ManyToManyMapping.performDataModificationEvent(ManyToManyMapping.java:838)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:160)
    at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:4260)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1441)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithPreBuiltChangeSet(UnitOfWorkImpl.java:1587)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.writeChanges(RepeatableWriteUnitOfWork.java:455)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:874)
    ... 141 more
Caused by: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID'  cannot accept a NULL value.
    at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
    at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.executeUpdate(Unknown Source)
    at com.sun.gjc.spi.base.PreparedStatementWrapper.executeUpdate(PreparedStatementWrapper.java:125)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:892)
    ... 164 more
Caused by: org.apache.derby.client.am.SqlException: Column 'FRIDAY_ID'  cannot accept a NULL value.
    at org.apache.derby.client.am.Statement.completeExecute(Unknown Source)
    at org.apache.derby.client.net.NetStatementReply.parseEXCSQLSTTreply(Unknown Source)
    at org.apache.derby.client.net.NetStatementReply.readExecute(Unknown Source)
    at org.apache.derby.client.net.StatementReply.readExecute(Unknown Source)
    at org.apache.derby.client.net.NetPreparedStatement.readExecute_(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.readExecute(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.executeUpdateX(Unknown Source)
    ... 167 more
我正在调试该方法，我正在成功地从计划中删除该元素。但是
scheduleDAO.update（schedule）
似乎不能完全工作。就像我说的，其他一切都完美无瑕

更新

我现在按照克里兹的建议，将其更改为单向关系，并删除
SchoolSubject.schedule
字段

更新的时间表类别：

@Entity
public class Schedule extends JPAEntity implements Serializable {

    /**
     * Die eindeutige SerialisierungsID.
     */
    private static final long serialVersionUID = -3554837193392512324L;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> monday;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> tuesday;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> wednesday;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> thursday;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @MapKey(name = "hourTime")
    private Map<Integer, SchoolSubject> friday;
我得到的错误如下：

    @Override
    public void removeSubject(User user, Schedule schedule, SchoolSubject oldSubject) {
        if (schedule.removeSubject(oldSubject.getHourTime() - 1, oldSubject)) {
            schoolSubjectDAO.remove(oldSubject);
        }

        scheduleDAO.update(schedule);
        try {
            userDAO.update(user);
        } catch (final DuplicateUniqueFieldException e) {
            throw new UnexpectedUniqueViolationException(e);
        }
    }

 public void addSubject(User user, Schedule schedule, SchoolSubject subject)
            throws DateAlreadyOccupiedException {
        schedule.addSubject(subject.getHourTime() - 1, subject);
        scheduleDAO.update(schedule);
        try {
            userDAO.update(user);
        } catch (final DuplicateUniqueFieldException e) {
            throw new UnexpectedUniqueViolationException(e);
        }
    }

Severe:   javax.faces.el.EvaluationException: javax.ejb.EJBTransactionRolledbackException
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101)
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
    at javax.faces.component.UICommand.broadcast(UICommand.java:315)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at de.unibremen.st.gradelog.filter.AuthorizationFilter.doFilter(AuthorizationFilter.java:94)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: javax.ejb.EJBTransactionRolledbackException
    at com.sun.ejb.containers.BaseContainer.mapLocal3xException(BaseContainer.java:2342)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2123)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2044)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:220)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
    at com.sun.proxy.$Proxy613.update(Unknown Source)
    at de.unibremen.st.gradelog.persistence.__EJB31_Generated__UserDAO__Intf____Bean__.update(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:434)
    at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:127)
    at org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
    at org.jboss.weld.bean.proxy.InjectionPointPropagatingEnterpriseTargetBeanInstance.invoke(InjectionPointPropagatingEnterpriseTargetBeanInstance.java:67)
    at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:100)
    at de.unibremen.st.gradelog.persistence.UserDAO$Proxy$_$$_Weld$EnterpriseProxy$.update(Unknown Source)
    at de.unibremen.st.gradelog.businesslogic.ScheduleManager.addSubject(ScheduleManager.java:56)
    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:498)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
    at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
    at sun.reflect.GeneratedMethodAccessor86.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
    at com.sun.proxy.$Proxy605.addSubject(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:498)
    at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:434)
    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 de.unibremen.st.gradelog.businesslogic.IScheduleManager$1688850411$Proxy$_$$_Weld$EnterpriseProxy$.addSubject(Unknown Source)
    at de.unibremen.st.gradelog.controller.ScheduleBean.save(ScheduleBean.java:100)
    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:498)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
    at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
    at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
    ... 41 more
Caused by: javax.ejb.TransactionRolledbackLocalException: Exception thrown from bean
    at com.sun.ejb.containers.EJBContainerTransactionManager.checkExceptionClientTx(EJBContainerTransactionManager.java:666)
    at com.sun.ejb.containers.EJBContainerTransactionManager.postInvokeTx(EJBContainerTransactionManager.java:511)
    at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4566)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2074)
    ... 109 more
Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150605-31e8258): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID'  cannot accept a NULL value.
Error Code: 20000
Call: INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)
    bind => [2 parameters bound]
Query: DataModifyQuery(name="monday" sql="INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)")
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:879)
    at org.eclipse.persistence.internal.jpa.QueryImpl.performPreQueryFlush(QueryImpl.java:967)
    at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:207)
    at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:473)
    at de.unibremen.st.gradelog.persistence.UserDAO.getUserForUsername(UserDAO.java:227)
    at de.unibremen.st.gradelog.persistence.UserDAO.update(UserDAO.java:151)
    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:498)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
    at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
    at sun.reflect.GeneratedMethodAccessor86.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    ... 107 more
Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150605-31e8258): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID'  cannot accept a NULL value.
Error Code: 20000
Call: INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)
    bind => [2 parameters bound]
Query: DataModifyQuery(name="monday" sql="INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)")
    at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:902)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeNoSelect(DatabaseAccessor.java:964)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:633)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:560)
    at org.eclipse.persistence.internal.sessions.AbstractSession.basicExecuteCall(AbstractSession.java:2055)
    at org.eclipse.persistence.sessions.server.ClientSession.executeCall(ClientSession.java:306)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:242)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:228)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeNoSelectCall(DatasourceCallQueryMechanism.java:271)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeNoSelect(DatasourceCallQueryMechanism.java:251)
    at org.eclipse.persistence.internal.queries.StatementQueryMechanism.executeNoSelect(StatementQueryMechanism.java:118)
    at org.eclipse.persistence.queries.DataModifyQuery.executeDatabaseQuery(DataModifyQuery.java:85)
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:904)
    at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3267)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1857)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1839)
    at org.eclipse.persistence.mappings.ManyToManyMapping.insertAddedObjectEntry(ManyToManyMapping.java:630)
    at org.eclipse.persistence.mappings.ManyToManyMapping.performDataModificationEvent(ManyToManyMapping.java:838)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:160)
    at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:4260)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1441)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithPreBuiltChangeSet(UnitOfWorkImpl.java:1587)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.writeChanges(RepeatableWriteUnitOfWork.java:455)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:874)
    ... 141 more
Caused by: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID'  cannot accept a NULL value.
    at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
    at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.executeUpdate(Unknown Source)
    at com.sun.gjc.spi.base.PreparedStatementWrapper.executeUpdate(PreparedStatementWrapper.java:125)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:892)
    ... 164 more
Caused by: org.apache.derby.client.am.SqlException: Column 'FRIDAY_ID'  cannot accept a NULL value.
    at org.apache.derby.client.am.Statement.completeExecute(Unknown Source)
    at org.apache.derby.client.net.NetStatementReply.parseEXCSQLSTTreply(Unknown Source)
    at org.apache.derby.client.net.NetStatementReply.readExecute(Unknown Source)
    at org.apache.derby.client.net.StatementReply.readExecute(Unknown Source)
    at org.apache.derby.client.net.NetPreparedStatement.readExecute_(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.readExecute(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.executeUpdateX(Unknown Source)
    ... 167 more
你不能像那样重复使用
mappedBy
。在您坚持
时间表
并尝试从数据库加载它之后，JPA无法知道哪些
科目
实体转到
周一
，哪些转到
周二
，依此类推。您试图做的是将关系的一侧（
SchoolSubject.schedule
）映射到多个相反的一侧（
schedule.monday，schedule.周二，
）。这在JPA中是非法的

我能想到的实现您想要的映射的唯一方法是使用单向关系（最好是而不使用连接列），如下所示：

@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> monday;
...

@OneToMany（cascade=CascadeType.ALL，orphan=true）
@映射键（name=“hourTime”）
私人地图星期一；
...
您还需要删除
SchoolSubject.schedule
字段（或者，为了保持双向关系，您需要每周每天在
SchoolSubject
中删除一个字段，但我猜这不是您想要的）

这样，JPA将把
Schedule
和
SchoolSubject
之间的关系保存在单独的联接表中，每周每天一个联接表（这样它们就不会混淆）。如果您确实需要联接列方法，请为每个映射使用单独的联接列（
monday\u id
，
suday\u id
等）（不要使用相同的列名，也不要使用主键列，我假设名为
id
的列为主键列）

你能添加removeSubject impl吗？还有，你能在更新之前执行merge吗？是的，我用这个方法更新了类计划，但是就像我说的，在调试时，这个方法似乎没有问题。它正在成功地从实体的映射中删除对象。合并实际上是由scheduleDAO.update（schedule）执行的，它基本上是javax.persistence.EntityManager中的merge（）方法，当添加一个元素并执行scheduleDAO.update（schedule）时，我看到一切都很好。您使用的是什么持久性提供程序？这个版本是什么？它是EliclipseLink（JPA2.1）谢谢你的回答！当我试图像您所说的那样解决这个问题时，我得到一个sql异常，表示列FRIDAY\u ID不能接受空值。我在数据库操作方面还真的没有经验，我现在应该如何继续？如果我发布整个错误跟踪会有帮助吗？如果你发布更新的代码会有帮助。我忘了提到，在上面的设置中，您不能将join列声明为
nullable=false
（如果您决定使用“每周每天字段”方法，您也不能使用
@manytone
侧的
optional=false
标志）我更新了新代码。我没有你建议的
@ManyToOne
关系，也没有
nullable=false
的join列，那可能是什么呢？根据当前映射，
SCHEDULE\u school subject
表应该不再存在。您确定在更新后从头开始重新创建了整个数据库架构吗？另外，尝试将
@JoinTable（name='schedule\u monday'）
，
@JoinTable（name='schedule\u tuday'）
（依此类推）添加到每个映射中表示存储
subject
的地图键与
subject.hourTime
的值不同。这是故意的吗？您确实意识到，在使用JPA从持久存储加载映射后，键将对应于
subject.hourTime
？