MyBatis批处理，使用foreach

1.批量插入

	<insert id="batchInsert" parameterType="java.util.List">
        insert into t_goods(title,sub_title,original_cost,current_price,discount,is_free_delivery,category_id)
        values
        <foreach collection="list" item="item" index="index" separator=",">
            (#{item.title},#{item.subTitle},#{item.originalCost},#{item.currentPrice},#{item.discount},#{item.isFreeDelivery},#{item.categoryId})
        foreach>
    insert>

测试代码：

/**
     * 批量插入测试
     */
    @Test
    public void testBatchInsert(){
        SqlSession session=null;
        try{
            long st=new Date().getTime();
            session=MyBatisUtils.openSession();
            List list=new ArrayList();
            for (int i = 0; i < 10000; i++) {
                Goods goods=new Goods();
                goods.setTitle("测试商品");
                goods.setSubTitle("测试子标题");
                goods.setOriginalCost(200f);
                goods.setCurrentPrice(100f);
                goods.setDiscount(0.5f);
                goods.setIsFreeDelivery(1);
                goods.setCategoryId(43);
                list.add(goods);
            }
//            insert()方法返回值代表本次成功插入的记录总数
            session.insert("goods.batchInsert",list);
//            提交事务数据
            session.commit();
            long et=new Date().getTime();
            System.out.println("执行时间:"+(et-st)+"毫秒");
        }catch(Exception e){
            throw e;
        }finally{
            MyBatisUtils.closeSession(session);
        }
    }

批量插入数据的局限性：

• 无法获取插入数据的id

• 批量生成的SQL太长，可能会被服务器拒绝

2.批量删除

	<delete id="batchDelete" parameterType="java.util.List">
        delete from t_goods where goods_id in
        <foreach collection="list" item="item" index="index" open="(" close=")" separator=",">
            #{item}
        foreach>
    delete>

测试代码

/**
     * 批量删除测试
     */
    @Test
    public void testBatchDelete(){
        SqlSession session=null;
        try{
            long st=new Date().getTime();
            session=MyBatisUtils.openSession();
            List list=new ArrayList();
              list.add(1910);
              list.add(1911);
              list.add(1912);
              list.add(1913);
//            delete()方法返回值代表本次成功删除的记录总数
            session.delete("goods.batchDelete",list);
//            提交事务数据
            session.commit();
            long et=new Date().getTime();
            System.out.println("执行时间:"+(et-st)+"毫秒");
        }catch(Exception e){
            throw e;
        }finally{
            MyBatisUtils.closeSession(session);
        }
    }