Mybatis关联映射一对多

Mybatis关联映射一对多
班级、学生一对多
studentMapper.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="studentMapper"> 
    <select id="getStudents" resultMap="getStudentMap">
        select * from class c,student s where s.classnumber=c.classnumber
    </select>
    <delete id="deleteStudents" parameterType="int">
        delete from student where id=#{id}
    </delete>
    <resultMap type="pojo.student" id="getStudentMap">
        <id column="id" property="id"></id>
        <result column="name" property="name"/>
        <result column="sex" property="sex"/>
        <result column="classnumber" property="classnumber"/>
        <result column="birth" property="birthday"/>
        <association property="c" javaType="pojo.classes">
            <id column="classnumber" property="classnumber"/>
            <result column="classname" property="classname"/>
        </association>
    </resultMap>
 
</mapper>

Mybatis关联映射一对多测试类

package test;

import java.io.InputStream;
import java.util.Date;
import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import pojo.student;

public class mytest {
	SqlSession session;
    
    @Before
    public void beforeLoadXML(){
        //加载 mybatis 配置文件
        InputStream inputStream = mytest.class.
                getClassLoader().getResourceAsStream("mybatis-configuration.xml");
        //构建sqlSession的工厂
        SqlSessionFactory sqlSessionFactory =
                new SqlSessionFactoryBuilder().build(inputStream);
        //根据 sqlSessionFactory 产生 session
        session = sqlSessionFactory.openSession();
    }
    
    @Test
    public void testgetAllStudents(){
    	String statement = "studentMapper.getStudents";
    	List<student> s = session.selectList(statement);
    	System.out.println(s);
    }
    
    @Test
    public void testDeleteStudent(){
       //字符串statement由 studentMapper.xml 文件中 两个部分构成
        //<mapper namespace="studentMapper"> 的 namespace 的值
        //<select id="deleteStudents" > id 值
    	testgetAllStudents();
    	String statement = "studentMapper.deleteStudents";
    	session.delete(statement,201402003);
    	session.commit();
    	testgetAllStudents();
        session.close();    	
    }

}

对应的注解开发就是新写一个接口类，.xml里的namespace值与接口类名对应；
接口方法名与sql语句的id值对应；就没什么大问题了

参考一
 参考二

Mybatis关联映射一对多

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