<insert id=" insert" parameterType="com.imooc.mybatis.entity.Goods">
    INSERT INTO t_goods(title,sub_title,original_cost,current_price,discount,is_free_delivery,category_id)
    VALUE (#{title},#{subTitle},#{originalCost},#{currentPrice},#{discount},#{isFreeDelivery},#{categoryId})
    <selectKey resultType="Integer" keyProperty="goodsId" order="AFTER">
        select last_insert_id()
    </selectKey>
</insert>

 @Test
    public void testInsert() throws Exception{
        SqlSession session = null;
        try {
            session = MyBatisUtils.openSession();
            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);
            //insert()方法返回值代表本次成功插入的记录总数
            int num = session.insert("goods.insert", goods);
            session.commit();
            System.out.println(goods.getGoodsId());
        } catch (Exception e) {
            if (session != null) {
                session.rollback();
            }
            throw e;
        }finally {
            MyBatisUtils.closeSession(session);
        }
    }
}