mybatis复杂结果集映射

多对一映射

多个学生对映一个老师

    <!--多表查询-->
    <select id="getAllStudent" resultMap="getAllStudent">
        select sid,sname,t.tid,name from student s,teacher t
        where s.tid = t.tid
    </select>
    <!--处理结果集-->
    <resultMap id="getAllStudent" type="student">
        <id property="sid" column="sid"></id>
        <result property="sname" column="sname"></result>
   <!--处理老师类型-->
        <association property="teacher" javaType="teacher">
            <id property="tid" column="tid"></id>
            <result property="name" column="name"></result>
        </association>
    </resultMap>

测试结果：

一对多映射

select t.tid,name,sid,sname from student s,teacher t
where s.tid = t.tid and t.tid = #{tid}

<resultMap id="getTeacher" type="teacher">
    <id property="tid" column="tid"></id>
    <result property="name" column="name"></result>
    <!-- 集合对应的泛型用oftype-->
    <collection property="students" ofType="student">
        <id column="sid" property="sid"></id>
        <result column="sname" property="sname"></result>
    </collection>
</resultMap>

测试结果：