-- Convert holiday statistics numeric columns from binary floating point to exact decimal storage.
-- Run once against the traffic_audit database.
ALTER TABLE holiday_passenger_flow
  MODIFY COLUMN passenger_count DECIMAL(30,15) NOT NULL COMMENT '发送旅客数（万人次）';

ALTER TABLE holiday_vehicle_flow
  MODIFY COLUMN vehicle_count DECIMAL(30,15) NOT NULL COMMENT '车流量（万辆次）';

ALTER TABLE holiday_passenger_coefficient
  MODIFY COLUMN coefficient DECIMAL(30,15) NOT NULL COMMENT '客运系数';

-- The seeded coefficient was averaged from repeated 2.4 cells through a Java double.
-- Normalize the migrated value to the exact Excel decimal.
UPDATE holiday_passenger_coefficient
SET coefficient = 2.4
WHERE year IN (2024, 2025, 2026);