<sqlMap namespace="ProductClass">
//产品小类结果集
<resultMap id="manyResult" class="java.util.HashMap">
<result property="xiaoid" column="xiaoid"/>
<result property="xiaoname" column="xiaoname"/>
<result property="parentid" column="parentid"/>
</resultMap>
//产品大类结果集
<resultMap id="oneResult" class="java.util.HashMap">
<result property="daid" column="daid" />
<result property="daname" column="daname" />
<result property="children" javaType="java.util.ArrayList" select="selectMany" column="daid" />
//这而的children属性javaType必须指定是java.util.List或java.util.Collection
</resultMap>
<select id="selectOne" resultMap="oneResult">
SELECT JZDL_DM as
daid,JZDL_MC
as daname from DM_JZDL
</select>
<select id="selectMany" resultMap="manyResult" parameterClass="string">
SELECT JZXL_DM as
xiaoid,JZXL_MC as xiaoname,JZDL_DM as parentid
from
DM_JZXL where
JZDL_DM=#daid#
</select>
</sqlMap>
<resultMap class="Department" id="dep" groupBy="id">
<result property="id" column="_id"/>
<result property="name" column="_name"/>
<result property="location" column="_location"/>
<result property="employees" resultMap="department.emp"/>
</resultMap>
<resultMap class="cn.com.legendapl.ibatis.domain.Employee" id="emp">
<result property="id" column="e_id"/>
<result property="name" column="e_name"/>
<result property="title" column="e_title"/>
</resultMap>
<select id="query" parameterClass="java.util.Map" resultMap="dep">
select
d._id,
d._name,
d._location,
e._id as e_id,
e._name as e_name,
e._title as e_title
from
t_dep as d
left join
t_emp as e
on
d._id = e._dep_id
<dynamic prepend="where">
<isNotEmpty property="id" prepend="and"> d._id = #id# </isNotEmpty>
</dynamic>
</select>
在名为dep的resultMap中配置一项groupBy="id"，这样，ibatis在处理结果集时，把id相同的几项“看成”一项来处理。
注意：groupBy属性的配置，是指的映射到的模型的property name 而不是查询的结果集的列名。