Mybatis一对多延迟加载方法映射错误

代码报错：


```java
org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for mapper.OrderDetailMapper.SelectByODId
### The error may exist in mapper/OrderMapper.xml
### The error may involve mapper.OrderMapper.orderAndDetail2
### The error occurred while handling results
### SQL: select * from `order` where id=?
### Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for mapper.OrderDetailMapper.SelectByODId

    at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:149)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:76)
    at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:87)
    at org.apache.ibatis.binding.MapperProxy$PlainMethodInvoker.invoke(MapperProxy.java:152)
    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:85)
    at jdk.proxy2/jdk.proxy2.$Proxy11.orderAndDetail2(Unknown Source)
    at TestDemo1.testSelect3(TestDemo1.java:65)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
    at java.base/java.lang.reflect.Method.invoke(Method.java:578)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
    at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
    at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
    at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)
Caused by: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for mapper.OrderDetailMapper.SelectByODId
    at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:1031)
    at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:821)
    at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:814)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getNestedQueryMappingValue(DefaultResultSetHandler.java:782)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getPropertyMappingValue(DefaultResultSetHandler.java:504)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.applyPropertyMappings(DefaultResultSetHandler.java:480)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getRowValue(DefaultResultSetHandler.java:404)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValuesForSimpleResultMap(DefaultResultSetHandler.java:354)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValues(DefaultResultSetHandler.java:328)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSet(DefaultResultSetHandler.java:301)
    at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:194)
    at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:65)
    at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
    at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)
    at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:325)
    at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:89)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)
    ... 34 more

mapper.xml 涉及部分:  


```xml
<resultMap id="OrderMapperDetail2" type="order">
        <collection property="orderDetailList" select="mapper.OrderDetailMapper.SelectByODId" fetchType="eager"  column="{orderId=id}">

        </collection>
    </resultMap>
    <select id="orderAndDetail2" resultMap="OrderMapperDetail2">
        select * from `order` where id=#{id}
    </select>

接口：

package mapper;

import entity.Order;
import entity.OrderDetail;

import java.util.List;

public interface OrderDetailMapper {
    OrderDetail SelectByODId(int id);
}

测试方法：


@Test
    public void testSelect3() throws IOException {
        OrderMapper orderMapper = sqlSession.getMapper(OrderMapper.class);
        Order order = orderMapper.orderAndDetail2(100);

        System.out.println(order);
        System.out.println(order.getOrderDetailList());

    }

```

路径没写完导致找不到相关mapper，这儿从com开始写

不知道你这个问题是否已经解决, 如果还没有解决的话:

你可以参考下这个问题的回答, 看看是否对你有帮助, 链接: https://ask.csdn.net/questions/7749270
我还给你找了一篇非常好的博客，你可以看看是否有帮助，链接：Mybatis中多表联查，查询出来的字段出现重名，造成数据异常的解决方法！

除此之外, 这篇博客: mybatis 一对多分页查询问题中的 解决方案： 部分也许能够解决你的问题, 你可以仔细阅读以下内容或者直接跳转源博客中阅读:

先分页查询user id，再根据userid 查询用户，虽然效率上会慢很多

<select id="selectUserByCond" resultMap="adminUserDto">
        select id, login, first_name, last_name, email, image_url, activated, lang_key,
            created_by, created_date, last_modified_by, last_modified_date, ua.authority_name roles
        FROM jhi_user u left join jhi_user_authority ua on ua.user_id = u.id
        where u.id in
        (
            SELECT
                distinct a. id
            from (
                select distinct id
                <if test="page.orderColumn != null and page.orderColumn.size() > 0">
                    <foreach collection="page.orderColumn" item="it" open="," close="" separator=",">
                        #{it,jdbcType=VARCHAR}
                    </foreach>
                </if>
                FROM jhi_user u left join jhi_user_authority ua on ua.user_id = u.id
                WHERE 1 = 1
                <if test="cond.search != null and cond.search != ''">
                    and ( login = #{cond.search, jdbcType=VARCHAR}
                        or first_name like concat('%', #{cond.search, jdbcType=VARCHAR}, '%')
                        )
                </if>
                <if test="cond.roles != null and cond.roles.size() > 0">
                    and ua.authority_name in
                    <foreach collection="cond.roles" item="it" open="(" close=")" separator=",">
                        #{it,jdbcType=VARCHAR}
                    </foreach>
                </if>
                order by #{page.order}
                limit #{page.offset}, #{page.size }
            ) a
        )
    </select>

SELECT id,
       login,
       first_name,
       last_name,
       email,
       image_url,
       activated,
       lang_key,
       created_by,
       created_date,
       last_modified_by,
       last_modified_date,
       ua.authority_name roles
FROM jhi_user u
         left join jhi_user_authority ua on ua.user_id = u.id
where u.id in (
    select a.id
    from (
             select distinct id, login
             from jhi_user u
                      left join jhi_user_authority ua on ua.user_id = u.id
             order by login
             limit 0, 2
         ) a
)

查询结果如下
在这里插入图片描述
结果正确，问题解决

您还可以看一下汤小洋老师的MyBatis入门视频课程课程中的映射文件小节, 巩固相关知识点

如果你已经解决了该问题, 非常希望你能够分享一下解决方案, 写成博客, 将相关链接放在评论区, 以帮助更多的人 ^-^

Mybatis一对多延迟加载 方法映射错误

Mybatis一对多延迟加载方法映射错误