校园商铺-4店铺注册功能模块-1Dao层之更新店铺

1. dao层增加更新店铺的方法

package com.csj2018.o2o.dao;
import com.csj2018.o2o.entity.Shop;
public interface ShopDao {
	/**
	 * 新增店铺
	 * @param shop
	 * @return 返回影响的行数；-1插入失败
	 */
	int insertShop(Shop shop);
	/**
	 * 更新店铺信息
	 * @param shop
	 * @return 返回影响的行数
	 */
	int updateShop(Shop shop);
}

2.mapper增加update方法的配置

<?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" >
 <!-- useGeneratedKeys="true"，一旦数据插入成功，使用JDBC的getGeneratedKeys获取数据库自增主键值 -->
 <mapper namespace="com.csj2018.o2o.dao.ShopDao">
	<insert id="insertShop" useGeneratedKeys="true"
		keyColumn="shop_id" keyProperty="shopId">
		insert into
		tb_shop(owner_id, area_id, shop_category_id, shop_name,
		shop_desc, shop_addr, phone, shop_img, priority,
		create_time, last_edit_time, enable_status, advice)
		values
		(#{owner.userId}, #{area.areaId}, #{shopCategory.shopCategoryId}, #{shopName},
		#{shopDesc}, #{shopAddr}, #{phone}, #{shopImg}, #{priority},
		#{createTime}, #{lastEditTime}, #{enableStatus}, #{advice});
	</insert>
	<update id="updateShop" parameterType="com.csj2018.o2o.entity.Shop">
		update tb_shop
		<set>
			<if test="shopName != null">shop_name=#{shopName},</if><!--Mybatis的另外一个优势是支持动态SQL的生成-->
			<if test="shopDesc != null">shop_desc=#{shopDesc},</if><!--<if test="属性 != null ">表字段=#{属性},</if>不是最后一行要加 ' , '-->
			<if test="shopAddr != null">shop_addr=#{shopAddr},</if>
			<if test="phone != null">phone=#{phone},</if>
			<if test="shopImg != null">shop_img=#{shopImg},</if>
			<if test="priority != null">priority=#{priority},</if>
			<if test="lastEditTime != null">last_edit_time=#{lastEditTime},</if>
			<if test="enableStatus != null">enable_status=#{enableStatus},</if>
			<if test="advice != null">advice=#{advice},</if>
			<if test="area != null">area_id=#{area.areaId},</if>
			<if test="shopCategory != null">shop_category_id=#{shopCategory.shopCategoryId}</if>
		</set>
		where shop_id=#{shopId}
	</update>
</mapper>

2.1 为什么需要动态SQL呢？

假设某一张表只有A和B两列，有时只需要更新A，有时只需要更新B，有时A和B都要更新。

如果不支持动态语句的话，就需要写3条update语句才能满足数据的更新，如果支持动态SQL，只需要写一个方法就可以了

<if test="shopName != null">shop_name=#{shopName},</if>
<!--先判断是否传入了shopName，如果传入，shopName不等于null，条件成立，将shop_name=#{shopName}添加到更新语句-->

3.测试类编写测试方法

package com.csj2018.o2o.dao;

import static org.junit.Assert.assertEquals;

import java.util.Date;

import org.junit.Ignore;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import com.csj2018.o2o.BaseTest;
import com.csj2018.o2o.entity.Area;
import com.csj2018.o2o.entity.PersonInfo;
import com.csj2018.o2o.entity.Shop;
import com.csj2018.o2o.entity.ShopCategory;

public class ShopDaoTest extends BaseTest{
	@Autowired
	private ShopDao shopDao;
	@Test
	@Ignore
	public void testInsertShop() {}

	@Test
	public void testUpdateShop() {
		Shop shop = new Shop();
		shop.setShopId(1L);
		shop.setShopDesc("江南皮革厂");
		shop.setShopAddr("皮革厂路1号");
		shop.setPhone("0571-3770571");
		shop.setLastEditTime(new Date());

		int effectedNum = shopDao.updateShop(shop);
		assertEquals(1,effectedNum);
		System.out.print(effectedNum);
	}
}