参考链接http://blog.youkuaiyun.com/qing_gee/article/details/47122227
解决方案一:
<select id="getTitleAndExplains" resultType="map" parameterType="string">
SELECT t.title,t.explain
FROM T_FLOW_S_EXPLAIN t
<if test="_parameter !=null and _parameter !=''">
where t.functionid=#{_parameter}
</if>
</select>
解决方案二:
List<Map<String, String>> getTitleAndExplains(@Param("id") String id);