Hibernate保存數據自動生成主鍵出現奇怪異常Duplicate entry '0' for key 1

今天在寫一塊程序的時候，出現了一個異常信息，搗鼓了一上午，終於找到了異常原因——不僅僅是簡單的主鍵沖突問題

測試數據庫：MySQL

異常信息如下：

org.hibernate.exception.ConstraintViolationException: could not insert: [org.xxx.entity.PropertyType]
	at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94)
	at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
	at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:64)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2176)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2656)
	at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71)
	at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
	at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:321)
	at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:204)
	at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:130)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
	at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
	at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
	at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:563)
	at org.hibernate.impl.SessionImpl.save(SessionImpl.java:551)
	at org.hibernate.impl.SessionImpl.save(SessionImpl.java:547)
	at org.xianfeng.hibernate.dao.HibernateDaoImpl.save(HibernateDaoImpl.java:110)
	at org.xianfeng.platform.property.service.impl.PropertyTypeServiceImpl.saveOrUpdate(PropertyTypeServiceImpl.java:58)
	at org.xianfeng.platform.test.TestPropTypeService.save(TestPropTypeService.java:31)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	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:38)
	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)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '0' for key 1
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
	at com.mysql.jdbc.Util.getInstance(Util.java:381)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
	at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
	at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2019)
	at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1937)
	at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1922)
	at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:105)
	at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94)
	at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57)
	... 40 more

通過異常信息可以確定——的確是數據庫表的主鍵沖突了

但是定義主鍵的時候是指定為native自動生成的，可是為什么還會沖突呢？並且把hibernate的實體類映射文件修改為assigned還是會出現相同的異常，這就真是奇了怪了

在網上搜羅了一下，也有人遇到過Hibernate主鍵沖突的異常，通常的原因都是指定的主鍵相同或者沒有把主鍵生成策略設置為native

可是我的程序明明都避免了這兩個原因，為什么還是會出現了呢？

快中午的時候，無奈之下，全部刪除重新寫一遍的沖動都有，后來想了想還是先從頭檢查一遍吧。在檢查的過程中，發現了主鍵沖突的真實原因——建表語句中的主鍵id沒有自動增長，即沒有指定為auto_increment

通過這次調試異常，似乎若有所思

1、Hibernate的異常機制還不是很完善，不能明確拋出具體的異常，以后在寫框架的過程中也需要完善框架異常

2、解決問題要有一套好的方法，不到萬不得已，不能刪除重寫，畢竟還是很耗費時間的

3、遇到問題要不煩不燥，雖然五一放假，但是也同樣需要更多的耐心

。。。。。。