作业4,5,6

 上代码;

DemoMapper接口:

 /**
     * 通过商品id修改商品名
     * @param map
     * @return
     */


    Integer updateGoods_nameById(Map<String,String > map);

DemoMapper.xml:

 <update id="updateGoods_nameById">

    UPDATE goods
<trim prefix="set" suffix="WHERE goods_id = #{userId}">

<if test="userName!=null and userName !=''">
    goods_name = #{userName}
</if>


</trim>


    </update>

效果:

 

 

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 直接上代码:

DemoMapper接口；

/**
 * 通过数组传参 foreach遍历查询信息
 * @param its
 * @return
 */

List<Goods> getGoodsListBy_in(Integer [] its);

DemoMapper.xml:

</select>
    <select id="getGoodsListBy_in" resultType="com.pojo.Goods">
SELECT * FROM goods where goods_id in
<foreach collection="array" index="index" item="item" open="(" separator="," close=")">
    #{item}
</foreach>
    </select>

测试类:

 @Test
    public void test04(){
        SqlSession sqlSession = MyBatisUtil.createSqlSession();

        DemoMapper mapper = sqlSession.getMapper(DemoMapper.class);

//        Map<String,String> map = new HashMap<String, String>();

        Integer [] its = {1,2,3};

        List<Goods> list = mapper.getGoodsListBy_in(its);

        for (Goods goods : list) {
            System.out.println(goods.getGoods_code()+" "+goods.getGoods_name());
        }
        MyBatisUtil.closeSqlSession(sqlSession);
    }

测试结果:

--------------------------------------------------------------------------------------

直接上代码:

接口:

 /**
     * 使用Map集合传参，通过foreach遍历查询信息
     * @return
     */

    List<Goods> getGoodsListBy_map(Map<String,Object> map);

xml:

    <select id="getGoodsListBy_map" resultType="com.pojo.Goods">

SELECT * FROM goods where goods_id in

这里的collection是相当于Map的key  我们要通过这个key找到对应的集合然后遍历，所以这里的collection = 测试的its---- key;
<foreach collection="its" index="index" item="item" open="(" separator="," close=")">
    #{item}
</foreach>
    </select>

测试类:

    @Test
    public void test05(){
        SqlSession sqlSession = MyBatisUtil.createSqlSession();

        DemoMapper mapper = sqlSession.getMapper(DemoMapper.class);

        Map<String,Object> map = new HashMap<String, Object>();

       List<Integer> list = new ArrayList<Integer>();

       list.add(1);
       list.add(2);
       list.add(3);
        map.put("its",list);
        List<Goods> goodsListBy_map = mapper.getGoodsListBy_map(map);

        for (Goods goods : goodsListBy_map) {
            System.out.println(goods.getGoods_code()+" "+goods.getGoods_name());
        }
        MyBatisUtil.closeSqlSession(sqlSession);
    }

测试结果: