Cause: No type handler could be found to map the property 'reporter' to the colu

在做根据ID查询一个带有外键的主表类时，如果在映射文件方法里返回结果使用相应类，则会报此种错误：Cause: com.ibatis.sqlmap.client.SqlMapException: No type handler could be found to map the property 'reporter' to the column 'reporter'.  One or both of the types, or the combination of types is not supported.

解决办法：使用resultMap。

错误代码：

<select id="selectPetitonLetterById" parameterClass="int" resultClass="PetitionLetter">
  	select * from t_petitionletter where id = #id#
  </select>

正确代码：

<resultMap id="PetitionLetterResult" class="PetitionLetter">
    <result property="id" column="id"/>
    <result property="identifier" column="identifier"/>
    <result property="reporter" column="reporter" select="selectReporter"/>
    <result property="letterInformation" column="letterInformation" select="selectLetterInformation"/>
    <result property="supervision" column="supervision" select="selectSupervision"/>
    <result property="processFlow" column="processFlow" select="selectProcessFlow"/>
  </resultMap>

<select id="selectPetitonLetterById" parameterClass="int" resultMap="PetitionLetterResult">
select * from t_petitionletter where id = #id#
  </select>