作业
直接上代码:
DemoMapper接口:
package com.mapper; import com.pojo.Goods; import java.util.List; import java.util.Map; public interface DemoMapper { /** * 通过 模糊商品名称,供应商ID,是否付款 来查询goods表的所有信息和provider表的名称 * @param map * @return */ List<Goods> getGoodsListBy(Map<String,String> map); }
DemoMapper.xml:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<?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"> <!--这里写接口的路径是因为光靠ID,是无法找到SQL语句的,必须通过namespace写接口路径才行--> <mapper namespace="com.mapper.DemoMapper"> <resultMap id="userList" type="Goods"> <result column="goods_code" property="goods_code"></result> <result column="goods_name" property="goods_name"></result> <result column="money" property="money"></result> <result column="pay_state" property="pay_state"></result> <result column="start_time" property="start_time"></result> <association property="provider" javaType="Provider"> <result column="provider_id" property="provider_id"></result> <result column="provider_name" property="provider_name"></result> </association> </resultMap> <select id="getGoodsListBy" resultMap="userList"> SELECT g.goods_code,g.goods_name,p.provider_id,p.provider_name , g.money,g.pay_state,g.start_time FROM goods g , provider p <trim prefix="where" prefixOverrides="AND |OR" suffix="AND g.provider_id = p.provider_id"> <if test="userName !=null and userName!=''"> g.goods_name LIKE concat('%',#{userName},'%') </if> <if test="user_pay_state!=null and user_pay_state !=''"> AND g.pay_state =#{user_pay_state} </if> <if test="user_provider_id!=null and user_provider_id !=''"> AND p.provider_id = #{user_provider_id} </if> </trim> </select> </mapper>
测试类:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
import com.mapper.DemoMapper; import com.pojo.Goods; import util.MyBatisUtil; import org.apache.ibatis.session.SqlSession; import org.junit.Test; import java.util.HashMap; import java.util.List; import java.util.Map; public class Junit { @Test public void test01(){ SqlSession sqlSession = MyBatisUtil.createSqlSession(); DemoMapper mapper = sqlSession.getMapper(DemoMapper.class); Map<String,String> map = new HashMap<String, String>(); map.put("userName",""); map.put("user_pay_state",""); map.put("user_provider_id",""); List<Goods> list = mapper.getGoodsListBy(map); for (Goods goods : list) { System.out.println(goods.getGoods_code()+" "+goods.getGoods_name()+" "+goods.getProvider().getProvider_id()+" "+goods.getProvider().getProvider_name()+" "+goods.getMoney()+" "+goods.getPay_state()+" "+goods.getStart_time()); } MyBatisUtil.closeSqlSession(sqlSession); } }
这里的测试我就不一一说了,我已经验证过,4中情况下都可以输入成功:
1、全部都写 2、全部都没写(查询所有) 3、任一写一个 4、任一写两个