shop--10.商品--解除商品与某商品类别的关联的实现

ProductDao.java

    /**
     * 删除商品类别之前，将商品类别Id置为空
     * 
     * @param productCategoryId
     * @return
     */
    int updateProductCategoryToNull(long productCategoryId);

ProductDao.xml

    <update id="updateProductCategoryToNull" parameterType="Long">
        UPDATE
        tb_product
        SET
        product_category_id = null
        WHERE
        product_category_id = 
        #{productCategoryId}
    </update>

接着将之前的ProductCategoryServiceImpl中的删除给完善好

    //由于先将商品类别 商品id置为空 再删除 分为两步 所以使用事务
    @Transactional
    @Override
    public ProductCategoryExecution deleteProductCategory(long productCategoryId, long shopId)
            throws ProductCategoryOperationException {
        // TODO 将此商品类别下的商品Id置为空
        //解除tb_product里的商品与该productcategoryId的关联
        try {
            int effectedNum = productDao.updateProductCategoryToNull(productCategoryId);
            if(effectedNum < 0) {
                throw new ProductCategoryOperationException("商品类别更新失败");
            }
        }catch (Exception e) {
            throw new ProductCategoryOperationException("deleteProductCategory error" + e.getMessage());
        }
        //删除该productCategory
        try {
            int effectedNum = productCategoryDao.deleteProductCategory(productCategoryId, shopId);
            if(effectedNum <= 0) {
                throw new ProductCategoryOperationException("商品类别删除失败");
            }else {
                return new ProductCategoryExecution(ProductCategoryStateEnum.SUCCESS);
            }
        }catch (Exception e) {
            throw new ProductCategoryOperationException("deleteProductCategory error :" + e.getMessage());
        }
    }