实体类
private int id;
private String name;
private List<Student> students;
private int id;
private String name;
private int tid;
按照结果嵌套处理
<select id="getTeacher" resultMap="TeacherMap">
select s.id sid,s.name sname,t.name tname,t.id tid
from student s,teacher t
where t.id = s.tid
and t.id = #{tid};
</select>
<resultMap id="TeacherMap" type="Teacher">
<result property="id" column="tid"/>
<result property="name" column="tname"/>
<collection property="students" ofType="Student">
<result property="id" column="sid"/>
<result property="name" column="sname"/>
</collection>
</resultMap>
按查询嵌套处理
<select id="getTeacher2" resultMap="TeacherMap2">
select * from teacher where id = #{tid}
</select>
<resultMap id="TeacherMap2" type="Teacher">
<collection property="students" javaType="ArrayList" ofType="Student" column="id" select="getStudentByTeacherID"/>
</resultMap>
<select id="getStudentByTeacherID" resultType="Student">
select * from student where tid = #{tid}
</select>