一、實體類package?com.liu.po;

/**

*?訂單類

*

*?@author?yingjie

*

*/

public?class?OrderInfo?{

private?Integer?orderId;

private?String?orderName;

private?Double?orderPrice;

private?UserInfo?userInfo;

public?UserInfo?getUserInfo()?{

return?userInfo;

}

public?void?setUserInfo(UserInfo?userInfo)?{

this.userInfo?=?userInfo;

}

public?Integer?getOrderId()?{

return?orderId;

}

public?void?setOrderId(Integer?orderId)?{

this.orderId?=?orderId;

}

public?String?getOrderName()?{

return?orderName;

}

public?void?setOrderName(String?orderName)?{

this.orderName?=?orderName;

}

public?Double?getOrderPrice()?{

return?orderPrice;

}

public?void?setOrderPrice(Double?orderPrice)?{

this.orderPrice?=?orderPrice;

}

@Override

public?String?toString()?{

return?"OrderInfo?[orderId="?+?orderId?+?",?orderName="?+?orderName

+?",?orderPrice="?+?orderPrice?+?",?userInfo="?+?userInfo?+?"]";

}

}

用戶類package?com.liu.po;

import?java.util.List;

/**

*?用戶信息的實體類

*

*?@author?yingjie

*

*/

public?class?UserInfo?{

private?Integer?userId;

private?String?userName;

private?String?userSex;

private?List?orderList;

public?List?getOrderList()?{

return?orderList;

}

public?void?setOrderList(List?orderList)?{

this.orderList?=?orderList;

}

public?Integer?getUserId()?{

return?userId;

}

public?void?setUserId(Integer?userId)?{

this.userId?=?userId;

}

public?String?getUserName()?{

return?userName;

}

public?void?setUserName(String?userName)?{

this.userName?=?userName;

}

public?String?getUserSex()?{

return?userSex;

}

public?void?setUserSex(String?userSex)?{

this.userSex?=?userSex;

}

@Override

public?String?toString()?{

return?"UserInfo?[userId="?+?userId?+?",?userName="?+?userName

+?",?userSex="?+?userSex?+?"]";

}

}

二、Mapper XML映射文件

多對一:<?xml ?version="1.0"?encoding="UTF-8"??>

mapper

PUBLIC?"-//mybatis.org//DTD?Mapper?3.0//EN"

"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

select?*?from?order_info

一對多<?xml ?version="1.0"?encoding="UTF-8"??>

mapper

PUBLIC?"-//mybatis.org//DTD?Mapper?3.0//EN"

"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

select

a.*,b.*

from

user_info?a,

order_info?b

where

a.user_id?=?b.user_id

and?a.user_id=#{userId}

三、Mapper 接口package?com.liu.mapper;

import?java.util.List;

import?com.liu.po.OrderInfo;

public?interface?OrderMapper?{

public?List?selectOrder();

}

package?com.liu.mapper;

import?com.liu.po.UserInfo;

public?interface?UserInfoMapper?{

public?UserInfo?selectUser(Integer?userId);

}

四、單元測試

package com.liu;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import com.liu.mapper.OrderMapper;

import com.liu.mapper.UserInfoMapper;

import com.liu.po.OrderInfo;

import com.liu.po.UserInfo;

import com.liu.utils.DBFactory;

public class OrderTest {

SqlSession session = null;

UserInfoMapper mapper = null;

OrderMapper orderMapper = null;

@Before

public void testBefore() {

session = DBFactory.getSession();

mapper = session.getMapper(UserInfoMapper.class);

orderMapper = session.getMapper(OrderMapper.class);

}

@After

public void testAfter() {

session.close();

}

@Test

public void selectOrder() {

List list = orderMapper.selectOrder();

for (OrderInfo order : list) {

System.out.println(order);

}

}

@Test

public void selectUser() {

UserInfo user = mapper.selectUser(4);

System.out.println(user);

List list = user.getOrderList();

for (OrderInfo order : list) {

System.out.println(order);

}

}

}

總結

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