org.apache.ibatis.exceptions.PersistenceException: Error querying database. Cause: java.sql.SQLException: Parameter index out of range (2 > number of parameters, which is 1). ### The error may e

1.笔者的目录结构如下:

2.由于单元测试报错:org.apache.ibatis.exceptions.PersistenceException:
### Error querying database.  Cause: java.sql.SQLException: Parameter index out of range (2 > number of parameters, which is 1).
### The error may exist in top/wajq/mapper/CustomerMapper.xml
### The error may involve top.wajq.mapper.CustomerMapper.findCustomerByNameAndJobs-Inline
### The error occurred while setting parameters
### SQL: select * from t_customer where 1=1        and username like concat('%','?','%')            and jobs=?
### Cause: java.sql.SQLException: Parameter index out of range (2 > number of parameters, which is 1).
    at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:111)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:102)
    at top.wajq.test.MybatisTest.findCustomerByNameAndJobs(MybatisTest.java:168)
    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 org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: java.sql.SQLException: Parameter index out of range (2 > number of parameters, which is 1).
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)
    at com.mysql.jdbc.PreparedStatement.checkBounds(PreparedStatement.java:3326)
    at com.mysql.jdbc.PreparedStatement.setInternal(PreparedStatement.java:3310)
    at com.mysql.jdbc.PreparedStatement.setString(PreparedStatement.java:4146)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:70)
    at com.sun.proxy.$Proxy9.setString(Unknown Source)
    at org.apache.ibatis.type.StringTypeHandler.setNonNullParameter(StringTypeHandler.java:31)
    at org.apache.ibatis.type.StringTypeHandler.setNonNullParameter(StringTypeHandler.java:26)
    at org.apache.ibatis.type.BaseTypeHandler.setParameter(BaseTypeHandler.java:50)
    at org.apache.ibatis.scripting.defaults.DefaultParameterHandler.setParameters(DefaultParameterHandler.java:81)
    at org.apache.ibatis.executor.statement.PreparedStatementHandler.parameterize(PreparedStatementHandler.java:80)
    at org.apache.ibatis.executor.statement.RoutingStatementHandler.parameterize(RoutingStatementHandler.java:61)
    at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:74)
    at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:59)
    at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:267)
    at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:137)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:96)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:77)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:108)
    ... 25 more

通过仔细阅读错误信息确定了是由于{SQL: select * from t_customer where 1=1        and username like concat('%','?','%')            and jobs=?}这句话产生了错误,大意是由于动态SQL语句不正确,所以查看sql配置:<select id="findCustomerByNameAndJobs" parameterType="top.wajq.bean.Custumer" resultType="top.wajq.bean.Custumer">
        select * from t_customer where 1=1
        <if test="username !=null and username != ''">
            and username like concat('%','#{username}','%')
        </if>
        <if test="jobs !=null and jobs != ''">
            and jobs=#{jobs}
        </if>
    </select> 

   多了引号。 正确如下: and username like concat('%',#{username','%')，果然对了。
总结：1.要对数据库的数据完整以及是否存在查询;

　　　2.mybatis是与数据库相关的所以极大多数是SQL语句的问题，排查数据库的语句问题；

　　    3.由于要进行mapper配置所以其中的名称信息需极细心，

　　    4.其次要进行单元测试从而达到查错的目的。