Mybatisペア、ペアマルチマッピング

原文のリンク:http://www.cnblogs.com/xdp-gacl/p/4264440.html
 

           ：association
    <!-- 
       ：    
        ：                     
                      (       )
    -->
    
    <!--   resultMap                  -->
    <resultMap type="me.gacl.domain.Classes" id="ClassResultMap">
        <id property="id" column="c_id"/>
        <result property="name" column="c_name"/>
        <association property="teacher" javaType="me.gacl.domain.Teacher">
            <id property="id" column="t_id"/>
            <result property="name" column="t_name"/>
        </association>
    </resultMap>
    
    <select id="getClass" parameterType="int" resultMap="ClassResultMap">
        select * from class c, teacher t where c.teacher_id=t.t_id and c.c_id=#{id}
    </select>
    

    
    <!-- 
       ：      
        ：        SQL              
    -->
    
     <!--   resultMap                  -->
     <resultMap type="me.gacl.domain.Classes" id="ClassResultMap2">
        <id property="id" column="c_id"/>
        <result property="name" column="c_name"/>
        <association property="teacher" column="teacher_id" select="getTeacher"/>
     </resultMap>
    
     <select id="getClass2" parameterType="int" resultMap="ClassResultMap2">
        select * from class where c_id=#{id}
     </select>
     
     <select id="getTeacher" parameterType="int" resultType="me.gacl.domain.Teacher">
        SELECT t_id id, t_name name FROM teacher WHERE t_id=#{id}
     </select>


		       ：collection
		<!--
		   :     :                      
     -->
    <resultMap type="me.gacl.domain.Classes" id="ClassResultMap3">
        <id property="id" column="c_id"/>
        <result property="name" column="c_name"/>
        <association property="teacher" column="teacher_id" javaType="me.gacl.domain.Teacher">
            <id property="id" column="t_id"/>
            <result property="name" column="t_name"/>
        </association>
        <!-- ofType  students         -->
        <collection property="students" ofType="me.gacl.domain.Student">
            <id property="id" column="s_id"/>
            <result property="name" column="s_name"/>
        </collection>
    </resultMap>
    
    <select id="getClass3" parameterType="int" resultMap="ClassResultMap3">
        select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.C_id=s.class_id and  c.c_id=#{id}
    </select>
    
    <!-- 
           ：    ：        SQL              
     -->
     <resultMap type="me.gacl.domain.Classes" id="ClassResultMap4">
        <id property="id" column="c_id"/>
        <result property="name" column="c_name"/>
        <association property="teacher" column="teacher_id" javaType="me.gacl.domain.Teacher" select="getTeacher2"></association>
        <collection property="students" ofType="me.gacl.domain.Student" column="c_id" select="getStudent"></collection>
     </resultMap>
     
     <select id="getClass4" parameterType="int" resultMap="ClassResultMap4">
        select * from class where c_id=#{id}
     </select>
     
     <select id="getTeacher2" parameterType="int" resultType="me.gacl.domain.Teacher">
        SELECT t_id id, t_name name FROM teacher WHERE t_id=#{id}
     </select>
     
     <select id="getStudent" parameterType="int" resultType="me.gacl.domain.Student">
        SELECT s_id id, s_name name FROM student WHERE class_id=#{id}
     </select>