org.hibernate.StaleStateException

1.异常：

org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:268)at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185)at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)at com.ever.config.App2.test2(App2.java:25)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.internal.runners.TestMethod.invoke(TestMethod.java:59)at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:98)at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:79)at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:87)at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:77)at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:42)at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:88)at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:51)at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:44)at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:27)at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:37)at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)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:459)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

出现org.hibernate.StaleStateException:  Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1

异常的原因:
1.使用的是hibernate的saveOrUpdate方法保存实例。saveOrUpdate方法要求主键为null（或不写）时才执行SAVE，在其它情况下执行UPDATE。在保存实例的时候是新增，但你的主键不为null，所以使用的是UPDATE，但是数据库里没有主键相关的值，所以出现异常。