mybatis多对多关联实战教程(推荐)

 DROP TABLE IF EXISTS `student`; CREATE TABLE `student` ( `id` int(11) NOT NULL, `name` varchar(255) DEFAULT NULL, `age` int(11) DEFAULT NULL, `gender` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `student` VALUES ('1', '刘德华', '55', '0'); INSERT INTO `student` VALUES ('2', '张惠妹', '49', '1'); INSERT INTO `student` VALUES ('3', '谢霆锋', '35', '0'); INSERT INTO `student` VALUES ('4', '王菲', '47', '1'); INSERT INTO `student` VALUES ('5', '汪峰', '48', '0'); INSERT INTO `student` VALUES ('6', '章子怡', '36', '1');

 DROP TABLE IF EXISTS `teacher`; CREATE TABLE `teacher` ( `id` int(11) NOT NULL, `name` varchar(255) DEFAULT NULL, `gender` varchar(255) DEFAULT NULL, `subject` varchar(255) DEFAULT NULL, `degree` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `teacher` VALUES ('1', '王晶', '0', 'CHINESE', '大专'); INSERT INTO `teacher` VALUES ('2', '冯小刚', '0', 'ENGLISH', '本科'); INSERT INTO `teacher` VALUES ('3', '吴京', '0', 'MATHEMATICS', '大专'); INSERT INTO `teacher` VALUES ('4', '王倦', '1', 'MATHEMATICS', '研究生');

 DROP TABLE IF EXISTS `stu_teach_rel`; CREATE TABLE `stu_teach_rel` ( `id` int(11) NOT NULL, `stu_id` int(11) NOT NULL, `teach_id` int(11) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `stu_teach_rel` VALUES ('1', '1', '1'); INSERT INTO `stu_teach_rel` VALUES ('2', '2', '1'); INSERT INTO `stu_teach_rel` VALUES ('3', '1', '2'); INSERT INTO `stu_teach_rel` VALUES ('4', '2', '2'); INSERT INTO `stu_teach_rel` VALUES ('5', '2', '3'); INSERT INTO `stu_teach_rel` VALUES ('6', '3', '1'); INSERT INTO `stu_teach_rel` VALUES ('7', '3', '2'); INSERT INTO `stu_teach_rel` VALUES ('8', '1', '3'); INSERT INTO `stu_teach_rel` VALUES ('9', '4', '1'); INSERT INTO `stu_teach_rel` VALUES ('10', '4', '2'); INSERT INTO `stu_teach_rel` VALUES ('11', '5', '3'); INSERT INTO `stu_teach_rel` VALUES ('12', '5', '4'); INSERT INTO `stu_teach_rel` VALUES ('13', '6', '1'); INSERT INTO `stu_teach_rel` VALUES ('14', '6', '3');

 package com.yihaomen.mybatis.model; import com.yihaomen.mybatis.enums.Gender; import java.util.List; public class Student { private String id; private String name; private int age; private Gender gender; private List teachers; setters&getters }

 package com.yihaomen.mybatis.model; import com.yihaomen.mybatis.enums.Gender; import com.yihaomen.mybatis.enums.Subject; import java.util.List; public class Teacher { private int id; private String name; private Gender gender; private Subject subject; private String degree; private List students; setters&getters }

 package com.yihaomen.mybatis.dao; import com.yihaomen.mybatis.model.Student; import org.springframework.stereotype.Repository; import java.util.List; @Repository public interface StudentMapper { List selectStudents(); }

       SELECT s.id, s.name, s.gender, t.id teach_id, t.name tname, t.gender tgender, t.subject tsubject, t.degree tdegree FROM student s LEFT JOIN stu_teach_rel str ON s.id = str.stu_id LEFT JOIN teacher t ON t.id = str.teach_id 

 package com.yihaomen.service.student; import com.yihaomen.mybatis.dao.StudentMapper; import com.yihaomen.mybatis.model.Student; import com.yihaomen.mybatis.model.Teacher; import com.yihaomen.service.BaseTest; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import java.util.List; public class TestStudent extends BaseTest { public static void testStuTeachRela() { SqlSessionFactory sqlSessionFactory = getSession(); SqlSession session = sqlSessionFactory.openSession(); StudentMapper mapper = session.getMapper(StudentMapper.class); List list = mapper.selectStudents(); for(Student s : list) { System.out.println("------------------"); System.out.println(s.getName() + "," + s.getAge() + "," + s.getGender()); for(Teacher t : s.getTeachers()) { System.out.println(t.getName() + "," + t.getGender() + "," + t.getSubject()); } } } public static void main(String[] args) { testStuTeachRela(); } }