MyBatis中一对一，一对多，多对一的用法

public class Teacher {  private Integer id;  private String name;  private List students;

  //......此处省略get,set方法}

public class Student{  private Integer id;  private String name;  private Teacher  teacher ;    //......此处省略get,set方法}

/***一对一：查某个学生信息并且查出他的老师*/Student queryStudentInfoById(@Param("id") Integer id);/***一对多: 查某个老师并且查出老师所有的学生*/Teacher queryTeacherInfoById(@Param("id") Integer id);/***多对一：查询所有同学并且查出同学对应的老师*/List queryStudentInfo();

              

    SELECT id,name,teacher_id FROM student WHERE id = #{id}  

    select  id,name  from teacher where id = #{teacher_id} 

              

    SELECT id,name FROM teacher where id = #{id}  

    select  id,name  from student where teacher_id = #{id} 

              

    SELECT id,name FROM student  

    select  id,name  from teacher where id = #{teacher_id}