Mybaits一对多处理。 一对多：比如：一个老师拥有多个学生！对于老师而言，就是一对多的关系！上一节，多对一地址：点击访问数据库（和上一篇Mybatis多对一的处理一样）CREATE TABLE `teacher` ( `id` INT(10) NOT NULL, `name` VARCHAR(30) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=INNODB DEFAULT CHARSET=utf8; INSERT INTO teacher(`id`, `name`) VALUES (1, '庞老师'); CREATE TABLE `student` ( `id` INT(10) NOT NULL, `name` VARCHAR(30) DEFAULT NULL, `tid` INT(10) DEFAULT NULL, PRIMARY KEY (`id`), KEY `fktid` (`tid`), CONSTRAINT `fktid` FOREIGN KEY (`tid`) REFERENCES `teacher` (`id`) ) ENGINE=INNODB DEFAULT CHARSET=utf8; INSERT INTO `student` (`id`, `name`, `tid`) VALUES ('1', '小明', '1'); INSERT INTO `student` (`id`, `name`, `tid`) VALUES ('2', '小红', '1'); INSERT INTO `student` (`id`, `name`, `tid`) VALUES ('3', '小张', '1'); INSERT INTO `student` (`id`, `name`, `tid`) VALUES ('4', '小李', '1'); INSERT INTO `student` (`id`, `name`, `tid`) VALUES ('5', '小王', '1'); 实体类（省略了构造函数、Setter/Getter）//Teacher类 public class Teacher { private int id; private String name; //一个老师拥有多个学生 private List<Student> students; } //Student类 public class Student { private int id; private String name; private int tid; } TeacherMapper接口（interface）//获取指定老师下的所有学生以及老师的信息 Teacher getTeacher(@Param("tid") int id); Teacher getTeacher2(@Param("tid") int id); 按照查询嵌套处理<select id="getTeacher2" resultMap="TeacherStudent2"> select * from mybatis.teacher where id = #{tid} </select> <resultMap id="TeacherStudent2" type="Teacher"> <collection property="students" javaType="ArrayList" ofType="Student" select="getStudentByTeacherId" column="id"/> </resultMap> <select id="getStudentByTeacherId" resultType="Student"> select * from mybatis.student where tid = #{tid} </select> 按照结果嵌套处理<!--按结果嵌套查询--> <select id="getTeacher" resultMap="TeacherStudent"> select s.id sid,s.name sname,t.name tname,t.id tid from student s,teacher t where s.tid = t.id and t.id = #{tid} </select> <resultMap id="TeacherStudent" type="Teacher"> <result property="id" column="tid"/> <result property="name" column="tname"/> <!--复杂的属性 对象：association 集合：collection 集合中的泛型信息，使用ofType获取 --> <collection property="students" ofType="Student"> <result property="id" column="sid"/> <result property="name" column="sname"/> <result property="tid" column="tid"/> </collection> </resultMap> 测试类@Test public void getTeacher(){ SqlSession sqlSession = MybatisUtils.getSqlSession(); TeacherMapper mapper = sqlSession.getMapper(TeacherMapper.class); Teacher teacher = mapper.getTeacher(1); System.out.println(teacher); sqlSession.close(); } @Test public void getTeacher2(){ SqlSession sqlSession = MybatisUtils.getSqlSession(); TeacherMapper mapper = sqlSession.getMapper(TeacherMapper.class); Teacher teacher = mapper.getTeacher2(1); System.out.println(teacher); sqlSession.close(); }