MyBatis其他方式来实现多表查询的操作
- 利用Java中的集合框架（List，Map）
- 其中List存储多个查询返回的记录
- Map查询返回字段，同时记录表中一条数据
<?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="com.gxa.mapper.StudentMapper_2">
<select id="getStudent" resultType="java.util.HashMap">
SELECT sid,sname,a.t_id,t_name FROM student a, teacher b WHERE a.t_id=b.t_id
</select>
</mapper>
package com.gxa.test;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import com.gxa.pojo.Student;
import com.gxa.pojo.Teacher;
import com.gxa.pojo.Team;
public class Test03 {
private static SqlSessionFactorysqlSessionFactory;
private static Reader reader;
static {
try {
reader = Resources.getResourceAsReader("config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (IOException e) {
e.printStackTrace();
}
}
@Test
public void m03() {
SqlSessionsqlSession = sqlSessionFactory.openSession();
String sql = "com.gxa.mapper.StudentMapper_2.getStudent";
List<Map<String, Object>> list = sqlSession.selectList(sql);
System.out.println(list);
sqlSession.close();
}
}
