-- 订单增加下游服务商名称（排货确认时写入 itfx 服务商名 / 分组名）。
-- 可重复执行。

SET @db := DATABASE();

SET @exists := (
  SELECT COUNT(1)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order'
    AND COLUMN_NAME = 'DownstreamSupplierName'
);

SET @sql := IF(
  @exists = 0,
  'ALTER TABLE `t_order` ADD COLUMN `DownstreamSupplierName` VARCHAR(128) NULL COMMENT ''下游 API 服务商名称'' AFTER `DownstreamSupplierCode`',
  'SELECT ''t_order.DownstreamSupplierName already exists'' AS info'
);

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;