我尽量叙事的清楚点吧，可能稍微啰嗦点。报错内容让我很头疼，我都开始怀疑mybatits 3.0.2 和mysql 5.1是不是本身就有bug了。

请大神们稍事略过下面的代码，然后我再叙述

项目使用到了spring 3  + mybatits 3.0.2 + mysql 5.1

在存储历史记录是报错。偶尔报错，感觉应该是万分之几的概率吧。

Caused by: org.springframework.dao.DuplicateKeyException: SqlSession operation; SQL []; Duplicate entry '5879889-35399' for key 'user_id'; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '5879889-35399' for key 'user_id'
	at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:241)
	at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72)
	at org.mybatis.spring.SqlSessionTemplate.wrapException(SqlSessionTemplate.java:364)
	at org.mybatis.spring.SqlSessionTemplate$7$1.doInSqlSession(SqlSessionTemplate.java:344)
	at org.mybatis.spring.SqlSessionTemplate.execute(SqlSessionTemplate.java:173)
	at org.mybatis.spring.SqlSessionTemplate.execute(SqlSessionTemplate.java:155)
	at org.mybatis.spring.SqlSessionTemplate$7.invoke(SqlSessionTemplate.java:339)
	at $Proxy59.addFavorite(Unknown Source)
	at -------------------------------------.addFavorite(---------.java:104)
	at -------------------------------------$$FastClassByCGLIB$$bf29fae7.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
	at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:692)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:625)
	at ------------------------------------$$EnhancerByCGLIB$$1aaa1136.addFavorite(<generated>)
	at-------------------------------------.addFavorite(--------.java:277)
	... 32 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '58179889-353994' for key 'user_id'
	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:411)
	at com.mysql.jdbc.Util.getInstance(Util.java:386)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1039)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3609)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3541)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
	at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
	at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1362)
	at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.execute(NewProxyPreparedStatement.java:989)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:22)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:51)
	at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:29)
	at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:73)
	at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:43)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:102)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:91)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:54)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:35)
	at $Proxy59.addFavorite(Unknown Source)
	at sun.reflect.GeneratedMethodAccessor926.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.mybatis.spring.SqlSessionTemplate$7$1.doInSqlSession(SqlSessionTemplate.java:342)
	... 48 more

   上面一堆横杆是我替换了我项目的路径或者类名，

    异常中得Duplicate entry '5879889-35399' for key 'user_id'我解释一下

    5859889是用户id，35399是书籍id，我再写sql的时候，明明是写对对应的字段的。但是在写入数据库的时候就报错了。

    sql如下

   <insert id="addFavorite"  useGeneratedKeys="true" keyProperty="id"  >
        INSERT INTO favorites (<include refid="favorite.columns" />
         <![CDATA[
        ) VALUES (
        	#{id} ,
        	#{userId} ,
        	#{bookId} ,
        	NOW() 
        )
    ]]>
  </insert>

   业务代码如下

favorite = new Favorite();
favorite.setBookId(bookInfo.getId());
favorite.setUserId(user.getId());
FavoriteFacade.addFavorite(favorite);// 加入收藏

    对于favorite的bookId和userId我都设置的是Integer类型。

    不知道为什么，两个字段的内容，再写入数据库的时候，就写在了一块。中间的 - ，是咋回事啊，哪里冒出来的啊？？？？数据库中user_id是int类型。

    项目跑了许久了。但是时不时就报着个错误。我感觉我的代码，写的没问题。所以就开始怀疑mybatits 3.0.2 和mysql 5.1是不是本身就有bug了。

    大神们，给点建议吧~~~