MyBatis基础-09-mybatis自关联一对多查询

mybatis.xml

EmployeeMapper.xml

	
	
		
		
		
	
	
	
		select id,name,job
		from t_employee
		where mgr=#{pid}
	
	
	
		select id,name,job
		from t_employee
		where id=#{id}
	

MyBatisUtil.java

package com.monkey1024.util;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

/*
 * DCL鐨勫崟渚嬫ā寮�
 */
public class MyBatisUtil {
	// 鏃犻渶灏嗘瀯閫犳柟娉曠鏈夊寲锛屽洜涓鸿繖閲岄潰鍙淇濊瘉鍒涘缓涓�涓猄qlSessionFactory鐨勫璞�
	// private MyBatisUtil()
	private static volatile SqlSessionFactory sqlSessionFactory;

	public static SqlSession getSqlSession() {
		try {
			if (sqlSessionFactory == null) {
				// 璇诲彇涓婚厤缃枃浠�
				InputStream input = Resources.getResourceAsStream("mybatis.xml");
				synchronized (MyBatisUtil.class) {
					if (sqlSessionFactory == null) {
						sqlSessionFactory = new SqlSessionFactoryBuilder().build(input);
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		//mybatis鑷姩鎻愪氦浜嬪姟
//		return sqlSessionFactory.openSession(true);
		return sqlSessionFactory.openSession();

	}
}

EmployeeDao.java

package com.monkey1024.dao;

import java.util.List;

import com.monkey1024.bean.Employee;

public interface EmployeeDao {
	List selectChildrenByPid(int mgr);
	
	List selectEmployeeByPid(int id);
}

EmployeeTest01.java

package com.monkey1024.test;

import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.monkey1024.bean.Employee;
import com.monkey1024.dao.EmployeeDao;
import com.monkey1024.util.MyBatisUtil;

public class EmployeeTest01 {
	private SqlSession sqlSession;
	private EmployeeDao employeeDao;
	@Before
	public void init(){
		sqlSession = MyBatisUtil.getSqlSession();
		employeeDao = sqlSession.getMapper(EmployeeDao.class);
		
	}
	@After
	public void closeSession(){
		if(sqlSession!=null){
			sqlSession.close();
		}
	}
	@Test
	public void selectChildrenByPid(){
		List employees = employeeDao.selectChildrenByPid(1002);
		employees.forEach(e->{
			System.out.println(e);
		});
	}
	@Test
	public void selectEmployeeByPid(){
		List employees = employeeDao.selectEmployeeByPid(1002);
		employees.forEach(e->{
			System.out.println(e);
		});
	}
	
}