-- ============================================================
-- 门店配送规则(阶梯配送费)升级脚本
-- 将固定的"配送价格"扩展为基于距离区间的"配送规则"
-- 配送规则存为 JSON 数组: [{minKm,maxKm,price}]，区间左闭右开
-- 无规则匹配时回退 delivery_price(默认配送费)
-- ============================================================

ALTER TABLE `yshop_store_shop`
  ADD COLUMN `delivery_rules` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci COMMENT '配送规则JSON:[{minKm,maxKm,price}]' AFTER `delivery_price`;

-- 可选:为已有支持外卖的门店初始化一条示例规则(请按需调整)
-- UPDATE `yshop_store_shop`
--   SET `delivery_rules` = '[{"minKm":0,"maxKm":3,"price":8},{"minKm":3,"maxKm":5,"price":12}]'
--   WHERE `distance` > 0 AND `delivery_rules` IS NULL;