MyBatis，集合的嵌套结果为空

问题描述：

我在MyBatis网站中创建一个具有嵌套集合的映射器，当我执行select操作时，我的对象（Provider）返回，但其中的集合（ ProviderParameter）是空的，当我转到数据库工具并应用相同的查询时，我得到预期的结果（集合也返回）。MyBatis，集合的嵌套结果为空

这里是我的映射：

<resultMap id="Provider" type="xxx.Provider"> 
     <result column="idProvider" property="idProvider"/> 
     <result column="providerType" property="providerType"/> 
     <result column="username" property="username"/> 
     <result column="password" property="password"/> 
     <result column="licenceInformation" property="licenseInformation"/> 
     <collection property="parameters" ofType="xxx.ProviderParameter"> 
      <result column="idProviderParameter" property="idProviderParameter"/> 
      <result column="name" property="name"/> 
      <result column="value" property="value"/> 
     </collection> 
    </resultMap>

和选择：

<select id="getProviderById" resultType="xxx.Provider"> 
    select P.idProvider   as idProvider 
      ,P.providerType  as providerType 
      ,P.username   as username 
      ,P.password   as password 
      ,P.licenceInformation as licenceInformation 
      ,PP.idProviderParameter as idProviderParameter 
      ,PP.name    as name 
      ,PP.value    as value 
    from [dbo].[msg_Provider] AS P 
    left outer join [dbo].[msg_ProviderParameter] AS PP on P.idProvider = PP.idProvider  
    where P.idProvider = #{idProvider} 
</select>

答

我的问题是，在选择我把与resultType而不是resultMap，但

所以选择应该是如：

<select id="getProviderById" resultMap="Provider"> 
    select P.idProvider   as idProvider 
      ,P.providerType  as providerType 
      ,P.username   as username 
      ,P.password   as password 
      ,P.licenceInformation as licenceInformation 
      ,PP.idProviderParameter as idProviderParameter 
      ,PP.name    as name 
      ,PP.value    as value 
    from [dbo].[msg_Provider] AS P 
    left outer join [dbo].[msg_ProviderParameter] AS PP on P.idProvider = PP.idProvider  
    where P.idProvider = #{idProvider} 
</select>

MyBatis，集合的嵌套结果为空

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