chengduzhongchuliang/migrations/20261028_quality_direction.sql

-- Apply once before deploying the editor/API changes. Adjust fa_ if using a custom prefix.
-- NULL preserves historical inference until a user explicitly saves a direction.
ALTER TABLE `fa_testing_params`
  ADD COLUMN `direction` varchar(5) DEFAULT NULL COMMENT '指标偏好：upper越小越好（高值预警）、lower越大越好（低值预警）';