org.apache.ibatis.exceptions.PersistenceException: 
### Error updating database.  Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for studentDao.insert
### Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for studentDao.insert
    at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:200)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:185)
    at cn.mgy.dao.impl.StudentDoImpl.insert(StudentDoImpl.java:14)
    at cn.mgy.test.StudentTest.insert(StudentTest.java:18)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    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$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for studentDao.insert
    at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:860)
    at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:693)
    at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:686)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:197)
    ... 26 more

1 <?xml version="1.0" encoding="UTF-8"?>
2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd" >
3 <mapper namespace="studnetDao">  <!--修改为 <mapper namespace="studentDao">-->
4   <insert id="insert" useGeneratedKeys="true" keyProperty="studentId">
5       INSERT INTO tb_student(STUDENT_NAME, STUDENT_PWD)
6     VALUES (#{studentName}, #{studentPwd})
7   </insert>
8 </mapper>