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  • A query was run and no Result Maps were found for...原来是mapper.xml文件出了问题,是使用MyBatis最常见的一种错误

    今天遇到一个问题,原来是mapper.xml文件出了问题,是使用MyBatis最常见的一种错误

    报错的结果是这样的:

     A query was run and no Result Maps were found for the Mapped Statement 'cn.zrgk.dao.RoleMapper.getRoleList'.  

      It's likely that neither a Result Type nor a Result Map was specified.
    org.apache.ibatis.executor.ExecutorException: A query was run and no Result Maps were found for the Mapped Statement 'cn.zrgk.dao.RoleMapper.getRoleList'. 
       It's likely that neither a Result Type nor a Result Map was specified. org.apache.ibatis.executor.resultset.FastResultSetHandler.validateResultMapsCount(FastResultSetHandler.java:177) org.apache.ibatis.executor.resultset.FastResultSetHandler.handleResultSets(FastResultSetHandler.java:150) org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:57) org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:70) org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:57) org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:259) org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:132) org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:105) org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:81) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) java.lang.reflect.Method.invoke(Method.java:606)

    我的mapper.xml文件中有个查询语句是这样写的:

       大家看看图一,好像根本没有错误,对吗?再看看

      是的,没错,我没有指定这个方法的返回类型,系统无法识别,于是就这样改了一下,发现不报错了

    所以平时啊,我们要多多注意这些细节,更要去多加理解

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  • 原文地址:https://www.cnblogs.com/dqh94/p/7455210.html
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