你的student表有有一条记录,比如他的学校id是1,然后你在学校表里面把id为1的记录删掉了。但是student里面记录没有任何改动。所以你去查的时候,student的学校id仍为1,但通过这个学校id,找不到记录。就报这个错误了。No row with the given identifier exists。可以在数据库里面设置他们级联删除的策略(你应该没有设置外键),或者在实现的时候用代码来判断。
对不起,我说的明确一点,譬如我数据库中有2个表,一个是student,一个是school,他们在hibernate里对应的关系是多对一,现在我不小心把school里的一条记录删除了,我在查找这条删除记录的student时,级联查询到对应的school,但是现在school已经删除,所以在获取student.getSchool.getName()(获取学校名子)时报异常,如下org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [org.ld.vo.Classes#7]
at org.hibernate.ObjectNotFoundException.throwIfNull(ObjectNotFoundException.java:27)
at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:128)
at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:177)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:87)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:862)
at org.hibernate.impl.SessionImpl.internalLoad(SessionImpl.java:830)
at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:266)
at org.hibernate.type.EntityType.resolve(EntityType.java:303)
at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:116)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:842)
at org.hibernate.loader.Loader.doQuery(Loader.java:717)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.loadEntity(Loader.java:1785)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:47)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:41)
at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:2730)
at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:365)
at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:346)
at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:123)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:82)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:862)
at org.hibernate.impl.SessionImpl.immediateLoad(SessionImpl.java:820)
at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:62)
at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:98)
at org.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:158)
at org.ld.vo.Student$$EnhancerByCGLIB$$4f3b49c3.getStuName(<generated>)
at org.ld.test.manytooneTest.testLoad2(manytooneTest.java:76)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:128)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)