-- 采集协议单分期：应缴费提前天数 + 各期缴费比例
ALTER TABLE `biz_protocol_payment`
  ADD COLUMN `installment_advance_days` INT NULL DEFAULT 30 COMMENT '第2期起应缴费提前天数' AFTER `installment_start_date`,
  ADD COLUMN `installment_ratios` VARCHAR(256) NULL COMMENT '各期缴费比例JSON数组' AFTER `installment_advance_days`;